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TRANSCRIPT
INTERVIEW
Novalux on how it hasadapted VCSELs tomeet market needs
Fibre-optic concretegives architects a newsource of inspiration
MATERIALS
NOVALUX TAKES VCSELS TO A NEW POWER LEVEL
SEMICONDUCTOR LASERS
The European magazine for photonics professionals
April 2004 Issue 116
INSIDEPHOTONICS EUROPE
SHOW PREVIEW
NEWS5 This month Fibre optic concrete lets the light in • Optical data
storage fuels blue laser diode market
6 Business Emcore wins solar cell deal • Revenue soars at Biolase • Rofin invests in fibre delivery skills
8 Analysis Why buy when you can partner?
TECHNOLOGY11 Applications Tough fibre sensor beats extremes • Optical
sensor tackles tuberculosis • Philips demonstrates fluid lens
14 R&D OFC showcases telecoms •Terahertz waves transmit music
15 Patents Medical laser makers lock horns over key patent
FEATURES17 Redesigned VCSELs take a leap in power
High-power infrared or visible light from a VCSEL-type architecture – could NECSELs offer an alternative to conventional laser technology? President and CEO of Novalux Jeff Cannon talks to Siân Harris.
21 Clearing up confusion in laser classificationThe class assigned to a laser is only part of the picture when deciding how it should be used safely. Karl Schulmeister describes some common pitfalls and misconceptions.
26 Photonic fibre finds its first applicationsA new type of optical fibre that rewrites the rules for guiding light is now coming of age. Rob van den Berg talks to three start-ups that are busy exploring the commercial potential and applications of photonic crystal fibre.
29 Careful mount design keeps mirrors alignedPicking the right mirror mount for your optical application could save you from hours of frustration. Colin Freeland gives a round-up of the different types of mount available.
SHOW PREVIEW34 Photonics Europe 2004
Your guide to the sessions and products that are not to be missed at the first ever Photonics Europe show in Strasbourg, France.
PRODUCTS43 Ultrafast lasers • Chillers • Retroreflectors • Framegrabbers
REGUL ARS20 Free Literature/Search Engine49 Recruitment50 Calendar
EDITORIALEditor Oliver GraydonTel: +44 (0)117 930 1015 [email protected]
Features editor Siân HarrisTel: +44 (0)117 930 [email protected]
Technology editor Jacqueline HewettTel: +44 (0)117 930 [email protected]
Production editor Lucy FarrarTechnical illustrator Alison Tovey
EUROPE/ROW SALESAdvertising sales manager Rob FisherTel: +44 (0)117 930 1260 [email protected]
Senior sales executive Simon AllardiceTel: +44 (0)117 930 1284 [email protected]
Key accounts manager Adrian ChanceTel: +44 (0)117 930 1193 [email protected]
US SALESSenior sales executive Debra WillsIOP Publishing Inc, Suite 929, 150 SouthIndependence Mall West, Philadelphia PA 19106, USATel: +1 215 627 0880 Fax: +1 215 627 [email protected]
ADVERTISING PRODUCTIONAdvertising production supervisor Rachel SermonTel: +44 (0)117 930 1277 [email protected]
Advertising production editor Joanne Derrick
CIRCULATION AND MARKETINGProduct manager Evie ForbesTel: +44 (0)117 930 1025 [email protected]
ART DIRECTORAndrew Giaquinto
PUBLISHERGeraldine Pounsford Tel: +44 (0)117 930 1022 [email protected]
PUBLISHING DIRECTORRichard Roe
OPTO & LASER EUROPEDirac House,Temple Back, Bristol BS1 6BE, UK. Tel: +44 (0)117 929 7481 Editorial fax: +44 (0)117 925 1942 Advertising fax: +44 (0)117 930 1178 Internet: optics.org/oleISSN 0966-9809 CODEN OL EEEV
SUBSCRIPTIONSComplimentary copies are sent to qualifyingindividuals (for more details see optics.org/ole/subscribe). For readers outside registration requirements: £111/€160 ($170 US and Canada)per year. Single issue £11/€16 ($15 US, Canadaand Mexico). CONTACT: IOPP Magazines, WDIS Ltd,Units 12 & 13, Cranleigh Gardens Industrial Estate,Southall, Middlesex UB1 2DB, UK.Tel: +44 (0)208 606 7518. Fax: +44 (0)208 606 7303.E-mail: opto&[email protected]
© 2004 IOP Publishing Ltd. The contents of OLE donot represent the views or policies of the Institute ofPhysics, its council or its officers unless so identified. This magazine incorporates Opto & Laser Products.Printed by Warners (Midlands) plc, The Maltings, West Street, Bourne, Lincolnshire PE10 9PH, UK.
I ssue 116 Apri l 2004 Contents
LED traffic signals get thegreen light in Aachen p7
Airborne LIDAR systemmaps salmon schools p13
Start-ups describe holeyfibre advances p26
SPIE launches PhotonicsEurope in Strasbourg p34
For the latest news on optics and photonics don’t forget to visit optics.org
Cover (Novalux) VCSELmaker adapts products tosurvive downturn. p17
Fibre optic concrete lets the light in
NEWSTHIS MONTH 5 BUSINESS 6 ANALYSIS 8
5OLE • Apr i l 2004 • optics.org
ARCHITECTURE
By Oliver GraydonThe days of dull, grey concretebuildings could be about to cometo an end. A Hungarian architecthas combined the world’s mostpopular building material withoptical fibre made by Schott to fab-ricate a new type of concrete thattransmits light.
A wall built from “LitraCon”allegedly has the same strength asone built from traditional concrete,but thanks to an embedded arrayof glass fibres it can display a viewof the outside world, such as thesilhouette of a tree.
“Thousands of optical glass fibresform a matrix and run parallel toeach other between the two mainsurfaces of every block,” explainedthe material’s inventor, ÁronLosonczi. “Shadows on the lighterside will appear with sharp outlineson the darker one. Even the coloursremain the same. This special effectcreates the general impression thatthe thickness and weight of a con-crete wall will disappear.”
The idea is that the new materialwill transform the interior envir-onment of concrete buildings by
making them feel light and airyrather than dark and heavy.
Losonczi, a 27-year-old architectfrom Csongrád, came up with theidea while he was studying at theRoyal University College of FineArts in Stockholm, Sweden. Afterdemonstrating the material atdesign exhibitions all over Europe,he has now formed a company to
commercialize the concept. The company, which is also
called LitraCon, is currently opti-mizing its manufacturing methodsand is planning to start selling pre-fabricated blocks of the materiallater this year.
“In theory, a wall structure builtout of the light-transmitting con-crete can be a couple of metres
thick, as the fibres work withoutany loss in light up to 20 m,” saidLosonczi. “Load-bearing struc-tures can also be built from theblocks, as glass fibres do not have anegative effect on the well-knownhigh compressive strength of con-crete. The blocks can be producedin various sizes with embeddedheat isolation too.”
Driven by strong demand for high-capacity DVD recorders, the mar-ket for blue/violet GaN laser diodesis set to soar with a compoundannual growth rate of 195% overthe next four years, according to astudy from Strategy Analytics, UK.Currently estimated at just $9 m(€7.27 m), the market is expectedto hit $272 m in 2008.
The report predicts that theemergence of blue/violet laser-based DVD recorders will quicklyovertake other established marketsfor GaN lasers such as printing,spectroscopy, biological agentdetection and laser projectors.
Indeed, the very first commercialDVD recorders that use blue
(405 nm) lasers have hit shops inJapan this year. Sony has alreadyreleased a model and Panasonic(Matsushita Electric) is preparingto launch one in July. Both arebased on the so-called Blu-ray for-mat and are designed to record sev-eral hours of high-definition TV.
In fact, by 2008, the report fore-casts that blue/violet DVD appli-cations will account for 97% of thetotal market for GaN lasers. Todaythe total market is far more divided,with 43% of sales listed under“other applications” in the report.
Asif Anwar, an analyst at the UKcompany, said that these “other”applications include microlithog-raphy, machine vision, metrology,
projection displays, bio-detectionand, intriguingly, underwater com-munication.
He believes that the proliferationof the technology will depend heav-ily on the development and com-mercial success of HD-TV, and thatthe standardization of the blue/vio-let DVD platform is essential.
“Despite the impressive growth,the existence of two competingstandards for violet-DVD, namelyBlu-ray and HD-DVD, will meanthat the GaN laser diode marketwill still be at an early stage ofdevelopment in 2008,” cautionedAnwar. “The influence of moviestudios and the IT industry will becrucial in deciding which format
becomes the accepted standard,and when next-generation DVDbegins to have mass appeal.”
GaN laser production is verymuch centred in Japan, saidAnwar: “Nichia maintains thelion’s share, but it will now start toface competition from other Japan-ese companies. Cree is expected toannounce a next-generation DVDlaser diode later in 2004.”
The Strategy Analytics report,“GaN laser diodes: markets andapplications”, also includes a tech-nology overview with a focus onsubstrate issues. Information onhow to obtain the report is avail-able from the company’s Web site.More: www.strategyanalytics.com
Optical data storage fuels blue laser diode market
Litr
aCon
Light-transmitting concrete called LitraCon is set to go on sale later this year. An embedded array of glass fibres allows thematerial to display the silhouette of shapes on the other side of the blocks.
MARKETS
Emcore wins solar cell deal
NEWSBUSINESS
SOLAR CELLS
6 OLE • Apr i l 2004 • optics.org
■ Lasers ■ Diodes ■ Optics ■ Scanners ■ Instrumentation ■ Micro-positioning
■ Service & Calibration center ■ Laser safety Euro
.Com
Emcore, the US semiconductorspecialist, has received a multi-mil-lion dollar contract from Boeing toprovide state-of-the-art solar cellsfor a high-power satellite that thecompany is constructing.
The model 702 satellite is beingdesigned for communication pur-poses, and is scheduled for launchin 2005. It will use 12 solar panelseach measuring 6 ×12 ft to gener-ate an electrical power of 18 kW,making it the highest-power model702 built to date. Each panel con-tains Emcore’s advanced triplejunction (ATJ) solar cells, whichuse layers of InGaP, InGaAs and Geto obtain an efficiency of 27.5%.
The ATJ cells are fully space
qualified and weigh just 84 mg persquare centimetre. Emcore saysthat the panels will be delivered bythe end of the year and that the
option for a second follow-on con-tract exists.
“We are very excited to be provid-ing our high-efficiency solar celltechnology to Boeing for the high-est-power model 702 satellite devel-oped,” commented Earl Fuller,vice-president of Emcore’s Photo-voltaic’s division. “Equipped withATJ solar cells, this satellite is able togenerate 18 kW of power at thestart of service and 15.5 kW at theend of its 15-year design life.”
Emcore managed to win thecontract even though Boeing is theowner of another high-efficiencysolar cell maker, SpectraLabs,which is also a specialist in triple-junction technology.
Powerhouse: a model 702 satelliteunder construction. The version nowbeing built will be able to generate18 kW of electrical power.
Boe
ing
Rofin-Sinar, the German maker ofsolid-state lasers, has acquired a90% stake in Optoskand AB, aSwedish developer of fibre-opticbeam delivery systems.
Optoskand is based in Gothen-burg and was founded in 2002 fol-lowing a spin-off from PermanovaLaserSystem AB. The firm has 25employees and its annual turnoveris around $3 m (€ 2.4 m).
Its fibre-optic systems deliver thehigh-power beam from a solid-statelaser to a workpiece that is to be cut,welded or marked. According toRofin, Optoskand’s fibres combinethe smallest losses on the marketwith a high damage threshold.
“Not only have we been a long-
time customer of Optoskand andenjoyed their quality in combi-nation with our various lasersources, but we also see this acquisi-tion as an opportunity to strengthenour market position in the compo-nent sector,” explained Rofin’s CEOPeter Wirth. “Optoskand will con-
tinue to operate as a stand-alonecompany and will also continue toprovide its products to other lasermanufacturers.”● Rofin-Sinar has also reportedits financial results for the threemonths ended 31 December2003. The firm had net sales of$71 m, a 22% rise over the sameperiod in 2002, while net incomerose 51% to reach $5.2 m.
“We had an excellent start toour new fiscal year, with strongsales and record earnings andorder intake,” commented Wirth.“Our Asian sales achieved a recordhigh due to increased demandfrom the semiconductor and elec-tronics industry.”
Rofin invests in fibre delivery skillsMATERIALS PROCESSING
Wirth: investing in the component sector.
Following a highly successfulEuropean project (TUNVIC) ontunable semiconductor lasers, tworesearchers from the TechnicalUniversity of Darmstadt, Ger-many, have formed a company tocommercialize long-wavelengthtunable VCSELs.
The start-up, called Two-ChipPhotonics AG, is now consideringthe market potential for its tunablelasers, which have a centre wave-length of 1550 nm and a tuningrange of about 30 nm. The lasersare made in collaboration withVertilas, the Walter Schottky Insti-tute in Munich and the TechnicalUniversity of Darmstadt.
Potential applications includegas sensing and inventory sparesfor telecom networks. Two-Chipalso offers a range of consultingservices for characterizing lasers.Its offerings include surface profil-ing, beam analysis and measure-ments of linewidth, chirp andbit-error-rate.
The lasers that were developedunder TUNVIC contain an InGaAsVCSEL with its top mirror removedand replaced with a movable MEMSmirror membrane. The laser’s emis-sion wavelength can be tuned byapplying a small current whichcauses the position of the mirrormembrane, and hence the length ofthe laser cavity, to change.
According to Two-Chip Photon-ics, its lasers are available in a TO5package and are capable of emit-ting output powers of 100 µW atroom temperature.
German start-up to commercializetunable VCSELs
START-UPS
Revenue soars at Biolase
NEWSBUSINESS
DENTAL LASERS
7OLE • Apr i l 2004 • optics.org
Biolase, the US maker of dentallasers, is going from strength tostrength. Since the beginning ofthe year, the firm has successfullycompleted a second public offering,announced encouraging end-of-year results, and expanded its salesforce and production capacity.
In February, the company made2.8 million shares available in itssecond public offering. Priced at$18.50 (€15.05) per share, theoffering netted Biolase just under$52 m, which was fed back intothe company on 3 March.
“With the offering behind us, wecan focus our resources on the busi-ness,” said Jeffery Jones, president ofBiolase. “We believe our balancesheet is now more in line with oursales growth. We intend to use theproceeds of the offering to addstrength to our growth and growthe company in a healthy fashion.”
Biolase’s expansion was evidenteven before the public offering. Forthe year ended 31 December 2003the company’s net sales came in at$49.1 m, up $21.8 m year-on-year. Cash flow from operatingactivities during 2003 was $6.3 m
compared with $477 000 for theprevious year. The company alsoposted a record net income for theyear of $19.1 m.
“We expect our annual operat-ing margin to expand from the15% annual rate achieved in2003,” Jones predicted. “During2004, we expect strong salesgrowth consistent with our histor-ical guidance of 40–50% and weexpect that our profitability willcontinue to increase.”
According to Jones, the com-pany’s short-term priority is mar-
ket penetration. To achieve thisgoal, Biolase has appointed newinternational distributors in ninecountries including Switzerland,the Netherlands, Russia and Brazil.It has also recruited seven newNorth American sales staff, takingits total workforce from 25 to 32.
To cope with the ever-increasingdemand for its products, Biolasehas also leased additional officeand manufacturing space at itsheadquarters in San Clemente,California. The new facility will beup and running by May 2004.
GE R M A N Y
Osram Opto Semiconductors issupplying the LEDs for a head-updisplay (HUD) that will feature inBMW 5 Series cars from this spring.The HUD is part of a driverinformation system that SiemensVDO Automotive is supplying toBMW. The LED light source, whichacts as the backlight for a liquid-crystal display, contains 128 high-brightness red and green LED chips.
KO R E A/JA PA N
Samsung Electronics and Sony areestablishing a joint company toproduce amorphous TFT LCDproducts. Called S-LCD, the newcompany will be based on an equaljoint investment by the two parties.The production line for seventh-generation amorphous TFT LCDpanels will be built at Samsung’sChungCheongNam-Do facility. Massproduction will start in the secondquarter of 2005.
UKUK-based optoelectronic chipmaker Intense Photonics says thatit is expanding its workforce andfacilities to handle demands fromnew markets such as printing anddefence. Having increased its totalstaff from 50 in late 2003 totoday’s 65, the firm says that itexpects this trend to continuethroughout the year. Intense saysthat it has also recently extended itscleanroom facilities by 25%.
GE R M A N Y
LINOS of Germany has recordedorders of €20.3 m for the first twomonths of fiscal 2004. This is anincrease of €10.4 m compared withthe same period last year, when theorder intake stood at €9.9 m.
CA N A DA
GSI Lumonics has announced thatits sales for fiscal year 2003 roseby 16.7% to $185.6 m (€150.9 m)compared with $159.1 m in 2002.The 2003 net loss of $2.2 m wasan improvement of $25.5 m overthe loss of $27.7 m for 2002.
IN BRIEF
The German city of Aachen hasawarded Siemens a €2 m contractto retrofit 111 of its traffic lightswith LEDs. The LEDs are a directreplacement for the incandescentbulbs used currently and offeradvantages such as lower mainte-nance costs, lower power con-sumption and longer lifetimes.
As part of a project betweenSiemens, Aixtron (a maker of opto-electronics fabrication equipment)and the city, LED traffic lights madetheir debut at a single road junctionin Aachen in 1998. After a suc-cessful and complaint-free trialperiod lasting five years, Aachenofficials are now deploying LEDtraffic lights on a larger scale.
“The installation of the LEDtraffic lights will start in the firstweek of April,” Andrea Maichin of
Aixtron told OLE. “Completion isplanned for May 2005. EighteenLEDs will be used for each colour.”
In 2002, market analysts esti-mated that 1.6 million LED trafficlights were in use worldwide –equivalent to an installation shareof 5%. And the popularity of LEDtraffic lights continues to grow asgovernments accept that the long-term savings outweigh the initialcost of deploying the technology.
The US state of California hasconverted approximately 10% ofits incandescent traffic lights toLED-based set-ups. Other citiesincluding Zurich in Switzerlandand Las Vegas in the US have alsobeen quick to adopt the technology.
Aachen adopts LED traffic lightsLEDS
LEDs on trial at Aachen’s test junction.
Jeffery Jones (right) says uptake of Biolase’s ‘Waterlase’, which uses laser lightcombined with a water–air mixture to cut oral tissue, has fuelled the firm’s growth.
Bio
lase
Aixt
ron
Why buy when you can partner?
NEWSANALYSIS
STRATEGIES
8 OLE • Apr i l 2004 • optics.org
By Siân HarrisIt seems that many large firms nowconsider partnerships rather thanacquisitions to be the best way toexpand their product range andbring new technology to the mar-ket. Recent examples of this strat-egy include deals struck betweenNewport Corporation and CrystalFibre, the Danish developer of pho-tonic crystal fibre; and betweenSpectra-Physics and SouthamptonPhotonics (SPI), the UK start-upwith fibre laser expertise.
The latter deal was announcedat the Photonics West show in Jan-uary and is the latest in a series ofpartnerships that Spectra-Physicshas set up. The firm told OLE thatpartnerships are now a centralpart of its strategy and it believesthat they are the best way to accel-erate the growth of its business.
“There is a heck of a lot of tech-nology out there and for us todevelop products in all of thosefields is probably unrealistic – we’dbe spread too thin with our engi-neering resources,” explained GuyBroadbent, Spectra-Physics’ CEO.“It makes more sense to focus ourresources on certain areas.”
Faced with this situation somelarger firms might consider acquir-ing a smaller business, but Broad-bent does not see this as the idealapproach. “First of all, 50 per centof all acquisitions fail. That’s just afact of life,” he said. “Another 30 percent are so-so and only 20 per centcreate a huge amount of value.”
He says that for a technologyacquisition to be successful, severalhurdles must be overcome. “Thereare many challenges when you doan acquisition in retaining the IP,knowledge and people. You mustalso make sure that the cultures fitand that you don’t end up with asprawling network of locationsaround the world that you have tointegrate and manage.”
Instead, Broadbent believes thatpartnerships are a faster andlower-risk way to take advantage
of new technology and get it to themarket-place. He adds that if theyare executed properly, such dealswill benefit both partners.
“The deal with SPI is set up to bea win–win situation,” said Broad-bent. “SPI had developed some[fibre laser] technologies and wasready to bring them to the market-place, while we have a strong brandand global distribution presence.”
There are benefits for SPI too.“This opens our technology up to awider market,” said Stuart Woods,director of business developmentat SPI. “As we grow and maturethis gives us access to a larger salesforce and a brand name that isestablished.” Woods says that SPIhopes that this partnership willcontinue for a number of years.
Tried and testedSpectra-Physics has already testedits partnership model with othercompanies. A few months beforethe SPI deal, it formed a partner-ship with Jenoptik in the disc laserfield. “We’ve worked closely withJenoptik over a number of years indifferent areas,” said Broadbent. “Away for the company to generate agreater return on investment was
to work with us, because it had notfully developed its distributionchannels on a global basis.”
He added: “This is a strategicpartnership that goes beyond iden-tifying existing products and dis-tributing them. We will look foropportunities to work on productstogether.” Broadbent wants thetwo firms to collaborate, whetheron concepts already in the pipelineor on new ideas that would exploittheir key technologies. One prod-uct launched at Photonics West2004 exemplifies that philosophy– a forensic fingerprinting system.
“This was not a product that wasenvisaged when we signed theagreement,” explained Broadbent.“It came out of looking at the prod-uct capabilities and identifying amarket for them, and is a goodexample of how once you’ve got therelationship going you can worktogether to create a new product.”
With their product lines and rep-utations so closely linked, it isimportant that companies selectthe right partners. “We look at ourstrategic plans, where our targetedmarkets are and how we supportthe customers in those markets,”said Broadbent. “We look for some-
body with good solid technologythat is already proven and robustrather than at a concept phase.”
Secondly, if a potential partner isgoing to supply the product, Spec-tra-Physics looks at the company’sfinancial and operational ability todeliver in volume over a period oftime. Broadbent thinks that senior-level commitment and regularreviews are also important. “Youset up a very clear contractualarrangement, which hopefully youjust put in the drawer and neverhave to look at again, because ifyou’ve got the relationships set upright those things get resolved inthe course of business.”
Supporting the customersSPI also had clear ideas of what itwanted from a partner. Accordingto Stuart Woods, SPI chose Spectraas a partner because it has a well-known brand name and was ableto provide the customer services,sales support and application sup-port that SPI needed. “There is a lotof work that has to be done withcustomers on applications,” hesaid. “We needed our partner toprovide knowledge of the cus-tomers and their applications.”
Woods believes that the key to asuccessful partnership is for bothparties to be committed to exchang-ing information and being honestand open with each other from thebeginning. “The early days arewhen this is the most critical,” heexplained. “It comes down to howindividuals work together, not justcorporate personalities.”
If this model works well for SPI,the venture capital-funded firmmay decide to pursue other part-nerships. The deal with Spectra-Physics covers fibre lasers but thecompany also offers other prod-ucts, particularly for the aerospaceindustry, and is keen to expandinto new markets. “Our value is inthe technology and partnershipsthat allow us to focus on develop-ing this,” concluded Woods.
Deal maker: Guy Broadbent of Spectra-Physics announces the firm’s partnershipwith SPI at the Photonics West show held in San Jose in January.
OLE
Tough fibre sensor beats extremes
TECHNOLOGYAPPLICATIONS 11 R&D 14 PATENTS 15
11OLE • Apr i l 2004 • optics.org
OPTICAL SENSORS
By Oliver GraydonA new type of optical pressure sen-sor that is able to operate underextreme conditions has been devel-oped by scientists in the US. Theteam from Mississippi State Uni-versity says that its optical fibresensor can measure pressures ofup to 18 million Pa (2620 psi).
What’s more, neither plungingthe sensor head into liquid nitro-gen at –196 °C nor heating it up to538 °C has any discernable effecton its performance. The hope isthat with further refinement thesensor will be suitable for use in jetpropulsion tests, in which condi-tions can reach extremes of15 000 psi and –254 °C.
The sensor is the brainchild ofChuji Wang and Susan Scherrerfrom the University’s DiagnosticInstrumentation and AnalysisLaboratory (DIAL), who appliedthe principles behind a well knownlaboratory technique called cavityring-down spectroscopy (CRDS) tooptical fibre sensing.
The result is a device called a fibreringdown sensor, which works by
measuring the decay time of a laserpulse travelling around a long loopof optical fibre. “So far, all ring-down techniques have been limitedto spectral measurements of tracegases and liquids,” said Wang andScherrer in a recent technical paper(Optics Letters 29 352). “To ourknowledge no-one has reported anattempt to introduce the ring-downconcept for fibre pressure sensordevelopment.”
Wang says that the new sensordesign offers many advantages overdesigns based on fibre Bragg grat-ings (FBGs) and fibre Fabry-Perotinterference (FPPI). “I confidentlypredict that this new idea will bring
a new generation of physical sen-sors that can measure pressure,temperature and strain for a varietyof applications,” Wang told OLE.“Our type of pressure sensor willpotentially have an extremely highupper measuring limit and theharshest temperature tolerance,with which FPPI- and FBG-basedsensors cannot compete.”
The sensor consists of two iden-tical 2×1 fibre couplers (99:1 split-ting ratio) and some standardsinglemode optical fibre (CorningSMF-28), which are connectedtogether into a 65 m-long loop.
A 1650 nm light-pulse from atemperature-controlled diode
laser is injected into the loop viaone of the couplers and circulatesaround the loop, becomingslightly weaker after each roundtrip. The strength of the signaland its decay time is monitoredcontinuously at the free port ofthe other coupler.
The key to the sensor’s operationis that the decay time of the light-pulse depends very strongly on theattenuation of the optical fibreloop. As a result, any phenomenonthat changes the transmission ofthe fibre, such as an external force(pressure), can be measured bymonitoring the decay time.
Tests applying weights to an8 mm-long section of the fibreshow that the sensor can measurea pressure of up to 1.8 ×107 Pa.Stripping away the fibre’s protec-tive jacket reduces its measuringrange, but increases its sensitivity.
As for his future plans, Wangsays that the design has alreadybeen patented and he is exploringthe possibilities for commercializ-ing the technology and makingsensor arrays.
Chuj
i W
ang
and
colle
ague
s
Under pressure: (left) this set-up shows the concept behind the fibre ringdownpressure sensor; (right) a fibre sensor in action on a block of concrete.
By Jacqueline HewettA UK inventor has come up with away to make what is thought to bean unpickable lock. Based on aclever mixture of optics and elec-tronics, Jeremy Rice has just won a£50 000 (€ 74 850) grant fromthe Scottish Executive to put his“Optilock” idea into practice.
“The idea has been 10 years inthe making and this money hasbeen the biggest break for me yet,”Rice told OLE. “At the moment, thelock is a computer model. Thismoney will allow us to see howthese ideas will work and what thedevices will actually look like.”
Most locks are picked by tweak-ing a series of levers in the lock orbypassing some sort of electronic
control system. Rice’s idea removesthese vulnerable components.
The Optilock contains a bundleof up to six input optical fibres onone side of the lock barrel, and acorresponding number of fibres onthe other side. When a special keyis inserted into the lock, it connects
the fibres in a unique routing pat-tern, opening the lock in a fractionof a second. Light then flowsaround the circuit until the key isremoved and the circuit is broken.
Rice says that the only way thatsomeone could pick the lock wouldbe to duplicate the key. “You could
potentially have as many differentpoints as you want on the lock bar-rel as inputs and outputs,” he said.“Because it is a 3D pathway you aredealing with, you have potentiallybillions or trillions of combinationsdepending on how the lock is made.The probability of duplicating thepath is very small.”
The first Optilocks have beendesigned for the automotive indus-try, but Rice says that the lockcould be scaled up and adapted forbuildings and other larger-scaleuses. He plans to use his award todevelop his idea into a product andis currently looking for industrialpartners to team up with. More: Jeremy Rice can be contactedvia e-mail at [email protected].
Unpickable optical lock aims to foil car criminalsSECURITY
Jeremy Rice’s patented Optilock invention contains a series of input and outputfibres which are connected when a specially designed key is inserted into the lock.
Jere
my
Rice
Optical sensor tackles tuberculosis
TECHNOLOGYAPPLICATIONS
OPTICAL SENSING
12 OLE • Apr i l 2004 • optics.org
A UK start-up has invented aportable optical biosensor thatscreens for tuberculosis (TB) byanalysing a person’s breath.According to its developers, Cam-bridge-based Rapid Biosensor Sys-tems (RBS), its prototype breathanalyser is not only portable andeasy to use, but also gives almostinstantaneous results.
Clinical trials are about to startin the UK and India and RBS isnow searching for healthcarefirms that are interested in pur-chasing a license in the technol-ogy. TB currently kills around twomillion people each year and is agrowing problem not only in devel-oping countries but also in FirstWorld countries, including the UK.
“Our test is very fast and givesresults within 10–15 min – yousimply cough into a tube,” saidDennis Camilleri, the chief execu-tive officer of RBS. “Potentially it
could do away with the need for aninjection skin test which has amuch longer turnaround time.”
The testing process is very sim-ple. If TB bacteria are present in thebreath sample then they bind to aspecial fluorescent bio-coatingthat has been applied to an optical
prism inside a collection tube.The tube is then placed inside an
optical reader which couples lightfrom a laser diode into the prism inorder to excite fluorescence fromthe coating. Analysis of the fluor-escence signal indicates whetherTB is present.
The compact size of the systemmakes it completely portable. Thecollection tube resembles anasthma inhaler, while the readerfits comfortably into the hand.
Camilleri says that because thesystem does not require samples tobe sent off to a lab for analysis, itcould potentially be used at air-ports and seaports to screen peopleas they enter a country. Thisenables the screening to be done“while you wait” so that peoplewith positive TB screening resultscan be isolated immediately.
“Nothing on the market comesclose to our system in terms of size,durability and results turnaround,”said Camilleri.
As for future developments, bychanging the pathogen bindingproperties of the coating the sen-sor could be reconfigured to diag-nose other non-airborne diseases,such as E. coli.
Japan’s Mitsubishi Electric hasdeveloped a “reversible” liquidcrystal display (LCD) that is able todisplay images on both its frontand rear surfaces. The companysays that its display could provide alighter, thinner and cheaper alter-native to the two separate displaysused in the majority of foldingmobile phones today.
The secret of the reversible LCD
is that it makes use of two trans-parent backlights. This means thatit contains only one liquid-crystalglass panel, which is sandwichedbetween the backlights.
Many folding mobile phonesinclude two displays: a large, maindisplay and a smaller sub-display,which is used when the handset isfolded shut. Because LCD back-lights usually contain non-trans-parent white lighting panels,conventional mobile phone designsincorporate two separate LCDs sothat they can display images onboth surfaces.
By contrast, the lighting panelsin Mitsubishi’s backlights aremade of invisible fine light-reflect-
ing prisms which appear transpar-ent when switched off and brightwhen switched on. Switching thetransparent backlights on or offenables the LCD to display imageson either its front side, its rear sideor both at the same time.
Both the display’s brightness,150 cd/m2, and its image qualityare said to rival those of conven-tional designs. Mitsubishi has filedfor four Japanese patents relatingto this technology and one patentis currently pending outside Japan.The company is now looking forpotential customers.
Reversible LCDpromises thinmobile phones
DISPLAYS
Seeing double: the reversible LCD usesone liquid-crystal glass panel sandwichedbetween two transparent backlights.
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Rapid analysis: RBS says its system can diagnose TB within 10–15 min.
Philips demonstrates fluid lens
TECHNOLOGYAPPLICATIONS
LIQUID LENSES
13OLE • Apr i l 2004 • optics.org
Philips Research has developed avariable-focus fluid lens that is justa few millimetres in size. The lens istargeted at high-volume productssuch as digital cameras and mobilephones, and Philips says that it willovercome the fixed-focus limita-tions of many of today’s low-costimaging systems.
This development sees Philipsfollowing in the footsteps of Frenchstart-up Varioptic and Bell Labs inthe US, both of which have demon-strated prototype liquid lenses.
Philips Research unveiled itsprototype at the CeBIT exhibitionwhich was held in Hannover, Ger-many, last month. Stein Kuiper, aresearcher from Philips Research,estimates that these devices couldbe in mass production within twoyears. “The quality of the lens is sogood and its potential so high thatcommercialization has a high pri-ority now,” he told OLE.
The lens consists of an electri-cally conducting aqueous solutionand a non-conductive oil whichare housed in a short tube withtransparent end caps. The internal
surface of the tube and one of theend caps are coated with a water-repellent coating.
The aqueous solution collects ina hemisphere at the uncoated endof the tube. This creates a sphericalcurved lens because the two liquidshave different refractive indices.“Typically the conductive liquid isa salt solution and the non-con-ductive liquid is a silicone oil,” saidKuiper. “For zoom applications wehave liquids with a large differencein refractive index in order to
obtain a high zoom factor. Forautofocus applications the differ-ence in refractive index is smaller,in order to obtain a more sensitivefocus action.”
The shape of the lens can beadjusted by changing the DC volt-age that is applied across the coat-ing, which changes the degree towhich it repels water. By increas-ing the applied electric field, thelens can change from being convexto completely flat or even concave.The prototype device can allegedly
change its focal length from 5 cmto infinity in less than 10 ms.
Philips’ prototype lens has adiameter of 3 mm and a length of2.2 mm and is expected to be well-suited to high-volume manufac-turing. “Simply drilling holes in aplate and covering them with twothin glass plates on both sides ispossible,” said Kuiper. “In this wayarrays of thousands of lenses canbe made and the plates can bediced to obtain individual lenses.”
The FluidFocus prototype is saidto consume very little power,implying that it could have benefitsfor small, battery-powered devices.Philips also claims that the lens hasperformed more than one millionfocusing operations with no loss ofoptical performance.
“We have made lenses that canperform the focus function below25 V by using thin insulating coat-ings and low surface tensions,”said Kuiper. “But generally we pre-fer to use thicker insulating coat-ings and high surface tensions asthis improves reliability, lens qual-ity and switching speed.”
Scientists in the US have packed aLIDAR system into a small aircraftand have used it to monitor adultsalmon returning to the streamwhere they were born to spawn.The developers from Colorado saythat their airborne LIDAR is builtaround a pulsed Nd:YAG laser anda gated intensified CCD camera,and provides information on thequantity and location of the fish(Applied Optics 43 1416).
“Salmon returning to spawn arefished by commercial, sport andsubsistance fishers as well as nat-ural predators,” explained one ofthe paper’s authors, James Churn-side from the National Oceanicand Atmospheric Administration.“Management involves opening
and closing different areas to fish-ing to ensure that enough fish sur-vive to spawn.”
Churnside says that airborneLIDAR is ideal because large areascan be mapped quickly, giving fish-ery managers an overview of thedistribution of fish. The team flythe system over the area of interestat a speed of 65 m per second andan altitude of 150 m.
The LIDAR system used byChurnside and his colleague JamesWilson is based on a Q-switchedNd:YAG laser. It produces 12 mJ of532-nm light in a 12 ns pulse at arepetition rate of 30 Hz. They alsouse a clever mixture of electronicsand a gated intensified CCD toimage the fish from the aircraft.
Although the laser can pene-trate some 50 m into the water, theduo admit that their camera sys-tem can only image fish to a depthof a couple of metres. Luckily,salmon returning to their natalstream tend to swim close to the
water’s surface.The LIDAR images show an area
of approximately 3.75 ×2.81 m.According to Churnside, the spa-tial resolution of the images is5.9 mm, which is sufficient toresolve individual fish.
Churnside and Wilson alsoprocess their images so that the fishcan be counted automatically. “Weare considering the use of the imag-ing system for identification ofschooling fish like sardines by theirschool shape,” added Churnside.“These schools are generally deeper,however, and we need to increasethe depth of penetration of theimaging system for that to be suc-cessful. We are looking at ways toincrease the signal to the camera.”
Airborne LIDAR maps salmon returning to spawnLIDAR
Fluid motion: Philips researchers unveiled a miniature variable-focus lens and acamera that contains the lens at last month’s CEBIT show in Hannover, Germany.
Phili
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An image from Churnside and Wilson’sstudy. Individual fish can be clearly seen.
OFC showcases telecoms
TECHNOLOGYR&D
OPTICAL COMMUNICATION
14 OLE • Apr i l 2004 • optics.org
Moving the NanoWorld
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● Passive optical networks:Samsung Electronics in Korea hasdemonstrated a passive opticalnetwork (PON) that provides 128users with 1.25 Gbit/s down-stream and 622 Mbit/s upstreamtransmissions. The PON, whichemploys 1×16 arrayed waveguidegratings and 1 ×8 splitters, hassixteen 100 GHz-spaced WDMchannels, each of which is sharedby eight subscribers using time-division multiplexing. (PDP4)
● High-performance modulator:Scientists from Intel in the US andIsrael say that their silicon-on-insulator, waveguide-based mod-ulator offers unique performancein silicon. The device boasts2.5 GHz small-signal bandwidthand a driver-limited extinctionratio of 5 dB at 1 Gbit/s. (PDP15)
● Low-cost CWDM: Researchersat Lucent’s Bell Laboratories inthe US have developed an8-channel CWDM multiplexer
based on silica-waveguide tech-nology. The device boasts channellosses between 3.1 and 5.5 dB, a1 dB bandwidth of 16.5 nm, andcrosstalk below 26 dB. The80 × 5.4 mm multiplexer doesn’trequire temperature control orhermetic packaging. (PDP11)
● Efficient fibre lasers: A UK col-laboration has come up with anovel method for maximizing theefficiency of distributed-feedbackfibre lasers. The OptoelectronicsResearch Centre at the Universityof Southampton and SPI Opticssay their technique offers a 57%increase in output power and effi-ciency over standard Er–Yb co-doped fibre designs. (PDP21)
● Low-loss holey fibre: BlazePhotonics of Bath, UK, and theUniversity of Bath reported a silicahollow-core photonic-bandgapfibre with a minimum attenuationof 1.72 dB/km at 1565 nm. Theresearchers say this developmenttakes such fibre closer to becominga practical option for long-hauldata transmission. (PDP24)
● Undersea transmission: TycoTelecommunications, US, has helda 10 Gbit/s field trial over 13 100km of installed submarine fibre.
Tyco transmitted 96 return-to-zero differential-phase-shift-keyed(RZ-DPSK) channels (with 33 GHzchannel spacing) between Wall,New Jersey, US, and Highbridge,UK. All channels demonstratedmore than 3 dB forward-error-cor-rection margin. (PDP34)
● Adaptive dispersion compensa-tion: The Technische UniversitätHamburg, Heinrich-Hertz-Institutin Berlin, and German firmsAdaptif Photonics and T-Systems,have demonstrated a dynamicpolarization-mode dispersion com-pensator that enables error-free160 Gbit/s RZ-DPSK transmissionover 75 km of installed singlemodefibre. The device is based on anelectro-optical polarization con-troller and magneto-optical polari-zation rotators. (PDP31)
● C-band tunable filters: LittleOptics, US, described a tunablebandpass filter for 50 GHz chan-nel spacings. Based on fifth-ordermicro-ring resonator filters, thefilter is tunable over 40 nm and isable to accommodate 100 chan-nels. (PDP9)
Tami Freeman is deputy editor ofFibreSystems Europe in associationwith LIGHTWAVE Europe magazine.
Unable to attend OFC? Here’sour pick of the postdeadlinepapers presented at theannual Optical FiberCommunication Conference.
Scientists at NEC in Japan claim tohave smashed the transmissiondistance record for quantum cryp-tography. The team says it success-fully sent a single photon over a150 km-long optical fibre link.This significantly extends the pre-vious record of 100 km, whichwas announced by ToshibaResearch Europe in June 2003.
Quantum cryptography uses astream of single photons to trans-fer a secret key between a transmit-ter and a receiver. Each bit of thecryptographic key is encoded upona single photon. Any attempt tointercept the key changes thequantum state of the photons,revealing the presence of a hacker.
NEC’s record-breaking systemrelies on planar lightwave circuittechnology and a low-noise photonreceiver. The system was developedby a collaboration of researchersfrom NEC, the Telecommunica-tions Advancement Organizationof Japan and the Japan Science andTechnology Agency.
NEC says that its system offers aten-fold increase in signal-to-noiseratio compared with current sys-tems. This is largely thanks to thereceiver’s increased sensitivity tophotons that have been broadenedby dispersion in the long fibre-optic link.
NEC breaks photontransmission record
QUANTUM CRYPTOGRAPHY
TECHNOLOGYR&D/PATENTS
15OLE • Apr i l 2004 • optics.org
PATENT INFRINGEMENTMedical laser makers lock hornsover key varicose vein patentDiomed has started legal action in the UnitedStates Federal District Court for the District ofMassachusetts against fellow US medical lasermaker Vascular Solutions. Diomed is seekinginjunctive relief and damages for infringement ofits US patent number 6 398 777, which coversendovascular laser treatment of varicose veins.
Diomed acquired the exclusive rights to thepatent from the five inventors of the procedure inSeptember 2003. “Diomed has committed toinvest $4.5 m (€3.65 m) in the acquisition of soleand exclusive rights to the key patent in the field,”said James Wylie, the firm’s president. “We plan todefend our legal rights under US patent law.”
But it looks as though Diomed could be in for along legal battle. “We have analysed the singleDiomed patent in this area and we have writtenopinion of non-infringement from our outsideintellectual property counsel,” said Howard Root,Vascular Solutions’ CEO. He added: “We believethat our Vari-Lase products do not infringe anyvalidly existing patent and we intend to vigorouslydefend this action.”
SETTLEMENTLED and substrate specialistssettle infringement lawsuitsCree and Boston University of the US havedropped their patent infringement lawsuit againstsubstrate maker AXT, also of the US. The lawsuit,which was brought against AXT in June 2003,concerned the alleged infringement of US patentnumber 5 686 738 entitled “Highly insulatingmonocrystalline GaN thin films”.
The patent, which Cree licenses from theuniversity on an exclusive basis, relates toGaN-based buffer layers used to make LEDs onsapphire and other substrates. Cree and theuniversity had alleged patent infringement basedon LEDs that were previously manufactured byAXT. AXT has now dropped all of its counterclaims.
The financial terms of the settlement have notbeen disclosed.
APPLICATIONSPhosphor-coated lens increasesefficiency of light-emitting diodesUS firm Gelcore is trying to patent a design whichit says increases an LED’s efficiency. The design,described in international patent application
WO 2004/021461, features a light-emitting chipand a hemispherical lens which is positioned a setdistance from the chip.
The idea involves coating the lens with auniformly thick layer of a fluorescent phosphor,which converts some of the radiation emitted bythe chip into visible light. Crucially, the authorsclaim that the surface area of the lens should beat least 10 times that of the LED chip. “Forincreased efficiency, the reflector and submountcan also be coated with phosphor to furtherreduce internal absorption,” said the authors.
Low macrobending loss opticalfibre carries telecoms wavelengthsCorning has come up with a method of producinga low macrobending loss optical fibre. As detailedin patent application WO 2004/019089, the USfirm claims that its fibre has a macrobending lossof less than 1 dB at 1550 nm for a bending radiusof 32 mm, as well as a cut-off wavelengthbetween 870 and 970 nm.
The authors say that the fibre’s core shouldhave a refractive index profile of between 1.7 and3.0, while the cladding region should have anouter radius in excess of 40 mm.
PATENTS
To search for recently published applications, visit http://pctgazette.wipo.int, http://ep.espacenet.com and axiom.iop.org
Researchers in Germany havetransmitted audio signals via tera-hertz waves for the first time. Thisdevelopment could lead to a newtype of high-speed short-rangewireless communication network.
Terahertz radiation occurs in thegap between infrared radiation andthe high-frequency radio wavescurrently used for mobile phonesand other wireless communica-tions systems. Apart from a fewapplications in biological imagingand spectroscopy, the potential ofthe region has been relatively unex-plored. But as demand for highdata-rate wireless communicationcontinues to grow, researchers areincreasingly turning to higher fre-quencies and are starting to con-sider the terahertz region.
In the latest research, scientistsfrom the Technical University of
Braunschweig built a room-tem-perature semiconductor terahertzmodulator. The researchers com-
bined the modulator with a modi-fied terahertz time-domain spec-troscopy set-up which transmitted
audio signals at up to 25 kHz over a75 MHz train of broadband tera-hertz pulses.
Music from a compact-discplayer was transmitted over thesystem. The researchers say thatthe quality of the music that wasplayed back through a loudspeakerwas similar to that produced byplaying music down a telephone.
Because terahertz radiation isstrongly absorbed by the atmos-phere, it is best suited to short-rangecommunication, such as picocellsthat cover single rooms. “Terahertzcommunications will not replacecell phones,” said research teammember Martin Koch. However,Koch does predict that wireless ter-ahertz networks could one dayreplace wireless local-area net-works or Bluetooth, which is ashort-range cable-replacement.
Terahertz waves transmit musicCOMMUNICATIONS
Terahertz team: two of the researchers, Thomas Kleine-Ostmann (left) and MartinKoch (right) show off the modulator that is used in the terahertz system.
High-power infrared or visible light from a VCSEL-type architecture is what US-based firmNovalux says its product offers. The company’s president and CEO Jeff Cannon tells
Siân Harris how NECSELs offer an attractive alternative to conventional laser technology.
Redesigned VCSELstake a leap in power
INTERVIEW
17OLE • Apri l 2004 • optics.org
When the telecoms industry started to fail acouple of years ago, manufacturers of verti-cal-cavity surface-emitting lasers (VCSELs)saw the market for their products plummet –and many firms did not survive.
“Many VCSEL manufacturers ended upwith a single product specifically designed forthis one market, and when this marketdeclined dramatically they did not have anadaptable product platform to address othernon-telecoms opportunities,” commented JeffCannon, president and chief executive officerof California-based Novalux. He speaks fromexperience – his company avoided disaster byswiftly adapting its platform to deliver visiblewavelengths and tackle different markets.
Novalux was able to make this shiftbecause its founder and chief technology offi-cer Aram Mooradian , a former professor atMassachusetts Institute of Technology, haddeveloped some ingenious techniques toextend the performance of standard VCSELs.The resulting technology, known as aNovalux extended-cavity surface-emittinglaser (NECSEL), is now starting to offer a realalternative to diode-pumped solid-state lasersand gas lasers in many applications.
Moving on from VCSELsVCSELs first emerged onto the market about10 years ago as a low-cost, high-yield lasersource. They emit in the infrared, which isideal for the telecoms market. Unlike othersemiconductor lasers, VCSELs emit light fromthe top of the chip so that each device can betested on the wafer. This cuts out the expen-sive and time-consuming process of cuttingup the wafer, polishing the devices, mountingthem on a heat sink and then connecting tothe electricity supply (which all side-emittinglasers diodes require before they can even betested). Testing on the wafer saves time andprocessing costs and reduces the risk ofdevices being damaged during production.
However, despite their advantages, Can-non says that standard VCSELs suffer thedrawback of a limited upper output power.
This is because their epitaxy layer is on top ofthe gallium arsenide (GaAs) substrate, withthe heat sink below that. This structure lim-its the amount of injection energy that can
be put into the device because GaAs is anineffective thermal conductor.
Another significant limitation of VCSELs isthe aspect ratio of the diameter of the activearea to the thickness of the epitaxial sand-wich. This creates a highly diverging, roundbeam. They also only lase at the wavelengthat which they were grown to operate.
These disadvantages restrict VCSELs toapplications that do not require high powerand in which the diverging beam can befocused by means of an additional compo-nent, such as an optical fibre. But in the hey-day of optical telecoms this situation suitedmany VCSEL manufacturers very well.
Meanwhile, however, Mooradian and hiscolleagues at Novalux were accumulatingintellectual property that appeared to solvethe problems of VCSELs and open up otherapplication areas. “Mooradian discoveredthat the way to increase the power was to putthe quantum well region as close to the heatsink as possible – by turning the VCSELupside-down,” explained Cannon. In thisnew design, the light goes through the GaAssubstrate, the poor optical transmission ofwhich is addressed by using the minimumthickness possible with low doping.
In addition, said Cannon, there was a needto open up the active region to distribute ahigher injection current more uniformly.While VCSELs typically have an active regionof 5–10 µm, Novalux has demonstratedNECSELs with active diameters of between20 and 300 µm.
Having tackled the output power issue –Novalux’s first products have output powersof 5–15 mW – the company began to look atthe highly diverging beam problem. It dis-covered that this can be solved by simply col-limating the light with a third mirror that isintegrated into the structure.
The presence of the third mirror opens upmore possibilities for the device becausethere can be an intracavity space betweenthe third mirror and the VCSEL chip intowhich the company can put a nonlinear
external mirrorextendedcavity
infraredbeam
doublingcrystal
metalization
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quantumwell region
p-DBR
visible beam
Novalux’s president and CEO, Jeff Cannon (top) isbuoyant about the potential of his company’sNECSEL architecture (above).
▲▲
INTERVIEW
optical material, making frequency doublingachievable. This creates NECSELs that canyield laser beams in the visible region from400 to 575 nm. Indeed, added Cannon, thisconversion can be highly efficient becausethe third mirror can be 100% infrared reflec-tive but transmit visible light in order to opti-mize the cavity parameters for a very highinfrared intracavity recirculating power.
Novalux’s first product, known as Protera,takes advantage of this frequency doubling.It evolved from a 980 nm source that thecompany was developing for telecoms appli-cations. When that market started to dry upthe company realized that frequency-dou-bling its source resulted in a 490 nm source –just 2 nm away from the established wave-length of 488 nm, which is widely used inbiological applications. And shifting the fun-damental lasing wavelength of the epitaxyby 4 nm from the telecoms wavelengthyielded 976 nm NECSELs, which could befrequency doubled to give 488 nm.
Providing an alternative“We had our telco product in the final stagesof development when that market collapsed,”explained Cannon. “In December 2001 wetook the decision to move away from the telcoplatform and by November 2002 we were
shipping our first frequency-doubled prod-uct, having completely re-engineered ourtechnology platform in 11 months.”
Due to the well-established fluorochromesin biological instrumentation, a 488 nmsource with a stable output power is impor-tant. This area has been served for manyyears by argon gas lasers, but these consumeconsiderable power and generate a largeamount of heat. Optically-pumped solid-state (DPSS) lasers are more efficient andsmaller, but they are currently two to threetimes more expensive than gas lasers.
A NECSEL, claims Cannon, is a good alter-
native to a gas laser because it is about thesame price but its electrical power consump-tion is considerably lower. For a gas laser togive 5–15 mW of output power an inputpower of 1.5 kW is typically required,whereas 50–100 W of input power is neededfor a diode-pumped solid-state laser. Yetaccording to Cannon, a NECSEL will yield thesame output power of 5–15 mW with just5 W of input power. In addition, he says thatProtera has a considerably longer lifetimethan a gas or DPSS laser.
One market of interest is instrumentation.Many biological instruments require multiple
Novalux has its own wafer fabrication equipment and laser assembly facilities (left). The companycurrently offers its Protera product at three different visible wavelengths: 488, 532 and 460 nm (right).
wavelengths. In fluorescence measurements,for example, instruments need to incorporatered, green and blue laser sources and thecompanies that make these devices oftenneed to talk to three different manufacturersand build in three different types of devices ofvarious sizes and power requirements. A488 nm blue gas laser head, for example, isabout the size of a 2 litre Coca-Cola bottle,with a power supply the size of a shoebox.Green light at 532 nm would usually be pro-vided by a diode-pumped solid-state Nd:YAGlaser that had been frequency doubled, whilered light would come from either ahelium–neon gas laser or from a red diode.
The NECSEL chip has approximately thesame footprint as an edge-emitting semicon-ductor laser: around 1×1 mm, with a heightof 100–200 µm. However, the external cav-ity is then added on top and the size of thatdepends on its application. The external cav-ity for an infrared emitter for telecoms appli-cations would be made of monolithic glassand would add 2–3 mm to the height. If thiscavity includes a frequency doubler thedevice would be around 15 mm long.
Because NECSELs are semiconductorlasers they can be grown at a range of differ-ent fundamental wavelengths. This meansthat Novalux’s second product, a 532 nmgreen source, can be made by simply shiftingthe parameters of epitaxial growth to createa 1064 nm NECSEL and selecting an appro-priate nonlinear material to frequency-dou-ble the output. The company’s third productis at 460 nm, which is another importantwavelength for biology and mandatory forgraphic art and digital imaging applications.It uses the same architecture as the Protera488, which results in the same stable outputpower and low noise beam characteristics.
Other devices are fixed to certain wave-lengths because of gas transmission lines ordesign constraints. Although NECSELs arenot tunable, their wavelengths can beadapted for specific applications. “Today,with epitaxial growth on GaAs substratesyou can go from 915 to 1150 nm and we cangrow a particular wavelength in this regionto within ±1 nm,” said Cannon.
Currently frequency doubling only yieldsvisible wavelengths from 458 nm blue lightup to 575 nm yellow light, but other wave-length ranges are possible by growing differ-ent III–V materials onto the GaAs substrate,says Cannon. The firm is looking at ways todirectly generate red light without having tofrequency double an infrared NECSEL.
“The high demand we are seeing now is forred in the 635–650 nm region,” he com-mented, adding that there is also interest in405 nm for bioanalytical instruments andholographic optical storage.
In producing high-power visible sourceNECSELs Novalux has moved well away fromthe roots of the technology in VCSELs. “Wedon’t really follow the VCSEL market,” saidCannon. “VCSEL manufacturers mostly tar-get the telco market and we don’t look atthem as competitors.”
And in the future the company could moveeven further away from traditional VCSELs.It is currently developing two other conceptsthat could evolve into commercial products.The first product, known as Stellar, is much
smaller than the Protera and is able to gener-ate visible light. The firm’s other project, theMagnus laser, is to make an array or strip ofNECSELs. These could be cut from a singlewafer and yield higher-power lasers for appli-cations such as flow cytometry and micro-materials processing.
Novalux is already discussing its ideaswith customers. And if Cannon’s predictionsare right, then ideas such as these could posea significant threat to the manufacturers oftraditional lasers. ■■
INTERVIEW
The Pan-European collaboration between BFi OPTiLAS andOphir has led to the implementation of a central calibrationlab based in its German facility (Puchheim / Munich).
It offers convenient access to fast and cheap repair & calibration of Ophir Power / Energy meters. Equipped with a full range of Lasers (CO2, YAG, Diodes,Excimer, Argon…) it allows fully traceable calibration at theend user wavelength.
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19OLE • Apri l 2004 • optics.org
Optikos
Photonic Solutions
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FREE LITERATURE/SEARCH ENGINE2004 Optics Catalogue
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Why Measure MTF?Modulation transfer function (MTF) has been associatedwith the measurement of the performance of opticalsystems since the initial introduction of linear systemanalysis to this field. As the demand for higher-quality,higher-resolution optical systems has becomeprevalent, both designers and metrology scientists havebegun investigating MTF as a mutual mode of opticalsystem characterization. This handbook serves toidentify the reasons for specification and measurementof MTF as a system characterization tool.
For more information please contact:Optikos Corporation, 286 Cardinal Medeiros Ave.Cambridge, MA 02141, USATel. +16173547557Fax +16173545946Internet: www.optikos.com
Kimmon HeCd Lasers
Kimmon is the oldest manufacturer of HeCd lasers inthe world, offering the largest range and highestpowers commercially available. With an installed baseof more than 25000, Kimmon offers the highest-power442nm (up to 180mW) and 325nm (up to 100mW)lasers with the best reliability and lifetime in thebusiness. Dual wavelength lasers and long coherencelength options (30cm) are available. Applicationsinclude CD mastering, Raman spectroscopy,holography, photoluminescence, stereolithographyand high-speed printing.
Contact: Photonic Solutions plcGracemount Business PavilionsUnit A, 40 Captains RoadEdinburghEH17 8QFTel. +131 664 8122 Fax +131 664 8144E-mail: [email protected] Internet: www.psplc.com
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Pacer ComponentsPacer Components is the leading supplier ofoptoelectronic components, assemblies andsensors for the commercial, industrial and militarymarkets. For non-opto environmental applications,Pacer can also supply high-reliabilitysurface-mount semiconductors and Hall effectsensors and assemblies.
Pacer has an established reputation forhigh-quality components and service to match,only representing market and technology leadersin their fields. Optoelectronic devices availablespan the spectrum from 185 nm to 45 µm, andfrom a low-cost plastic phototransistor to a modulethat detects and counts single photons of light.
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Clearing up confusionin laser classification
LASER SAFET Y
21OLE • Apri l 2004 • optics.org
In Europe, as well as many countries else-where, every product that contains a laser oran LED needs to be assigned a safety class.This includes everything from products thatcontain low-power diodes, such as CD play-ers, right up to the high-power lasers used inindustry for materials processing.
This class is defined by the European stan-dard EN 60825-1 (or the international stan-dard IEC 60825-1) and indicates, in broadterms, the harm to the eyes or skin that couldresult from exposure to emitted radiation(see box). The meanings of the various lasersafety classes and their limitations can bequite involved, which inevitably means thatthey are easily misunderstood.
Such misunderstandings can arise becauseworst-case assumptions are built into the clas-sification procedure. In other words, laserwarning labels can sometimes indicate a levelof hazard that does not apply in reality. Forinstance, many Class 3B and Class 4 productsare safe in practice because the hazards asso-ciated with them only crop up in special situa-tions. Examples include products with highlydivergent beams such as line lasers, scannedlasers, or emissions from optical fibres, wherethe hazard only exists close to the source.
If a Class 3B line projector is mounted onthe ceiling, for instance, people on the groundmight be well below the maximum permittedexposure limits and have no need for eye pro-tection. In this case, the hazard only becomesrelevant for maintenance personnel, whowould need to observe safety precautions ifthey were up a ladder cleaning the optics, forexample. Other examples are Class 3B and 4lasers that have a larger hazard zone but inwhich the radiation is contained by an enclo-sure. This is typically the situation for higher-power materials-processing installations.
It might seem misleading to put a Class 3Bor 4 warning label onto practically safe prod-ucts such as these, making it tempting to referto them as being “Class 1 (except in special
cases)”. However, to do so would constitute amisclassification under the IEC 60825-1standard, and classification must be carriedout according to this standard if the manu-facturer states that their product follows it.Users, manufacturers and safety inspectorsshould therefore simply bear in mind that theclassification indicates a worst-case hazard.
Because the classification is not solely
dependent on the laser’s power it is possiblein theory for devices that contain high-power lasers to be Class 1 products, as long asthey are completely enclosed and a numberof strict criteria are fulfilled. However, it isoften unnecessary, impracticable and tooexpensive for manufacturers to meet theserigorous requirements.
For example, many materials processing
Class 1 Safe because either the laser has a very low output power or it is enclosed. Maximum powers* of 0.4 mW for red continuous-wave (CW) lasers and 0.04 mW for blue. Examples include laser scanning ophthalmoscopes, low-power rangefinders and mostLEDs. With enclosure, CD players, laser printers and some fully enclosed materials processing machines are also included.
Class 1M Safe for unaided viewing but potentially hazardous when exposure occurs while using optical instruments.+ Maximum power as for Class 1 but different measurement apertures and distances. Examples include some LIDAR (i.e. larger-diameter collimated beams), some lasers with optical fibre outputs and high-power infrared LEDs (i.e. systems with divergent beams).
Class 2 Visible low-power (up to 1 mW) laser beams. Safe for accidental exposure (even with the use of optical instruments). Protection by aversion responses to bright light. Potentially hazardous if users stare directly into beam for prolonged period. Examples include visible alignment lasers and laser pointers.
Class 2M As for Class 2, but potentially hazardous when exposure occurs while using optical instruments.+ Power as for Class 2 but measurement apertures and distances differ. Examples are some visible LIDAR and large-aperture optical test instruments, some visible lasers with optical fibre outputs and some visible LEDs.
Class 3R Momentary (unintended) exposure is considered safe, but direct intrabeam viewing ispotentially hazardous. Reduced safety factor in comparison to Class 1 and Class 2. Visible power limit of 5 mW and non-visible limit of five times the limit of Class 1. Examples include alignment lasers and targeting lasers.
Class 3B Medium-power laser (up to 500 mW CW with a wavelength of more than 315 nm). Direct ocular exposure is hazardous (within hazard distance), but diffuse reflections are usually safe. Examples include scientific lasers, large area illuminators (e.g. industrial holography), laser displays and higher-power line lasers.
Class 4 High-power laser with no maximum power limit. Direct exposure is hazardous to eye and diffuse reflection may also be hazardous (within hazard distance). Skin and potential fire hazard. Examples are lasers for materials processing and medical lasers.
* The limits refer to the power measured through some given aperture. For beams larger than the aperture, the total output can be higher. Power values given are for small sources, and can be up to 66 times greater for extended sources.
+ “Optical instruments” is used in place of “binoculars/telescopes” or “magnifiers”. Generally only one or other type of optical instrument leads to an increase in the hazard for a given laser product.
Simplified laser classifications The class assigned to alaser is only part of thepicture when deciding how itshould be used safely, asKarl Schulmeister reports.
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lasers have walk-in access, meaning that intheory, the user could walk inside the hous-ing, close the door and start the laser. Andsome laser systems do not have a roof, sothere is the possibility of hazards resultingfrom reflections or single fault conditions.For an embedded product to really be Class 1it needs to be fully enclosed; walk-in accesshas to be detected; and the housing has to beable to withstand the radiation even underfault conditions. Without these additionalmeasures, a higher class must be assigned
because classification is based on the designof the product and cannot rely on appropri-ate behaviour from the user.
Analysing the risksIn practice, as long as the user treats the laserwith respect, it is not really important howthe product is classified. However, a Class 3Bor 4 classification usually means that a riskanalysis should be performed to evaluate thesafety of the product in a specific application.
Risk analysis is usually performed by a
qualified laser safety officer, but it might alsobe acceptable to rely on the analysis thatneeds to be done on a general basis by themanufacturer in the process of CE marking.A CE mark denotes that the manufacturerdeems the machine safe, even if it is labelledas a Class 4 laser product. The manufactureralso has to inform the user of the specific haz-ards presented by the laser product, and pro-cedures for safe use. The result of the riskanalysis might well be that no further controlmeasures are necessary, except to providesome information (in the manual) or train-ing regarding the special situations in whichthe hazard can be present. However, it isimportant that the user still analyses the spe-cific risks on a case-by-case basis.
It must also be recognized that correctlyclassifying the product according to the laserclassification standard and following thehardware requirements for the respectiveclass does not necessarily make the productsafe. Even if a Class 4 laser system with a col-limated open (i.e. not enclosed) beam meets
all the applicable requirements of its class,such as warning labels, emission indicator,beam attenuator and key control, it is obvi-ously not a safe product. It is necessary forthe user to be trained, to adopt safe workingprocedures and to use personal protectiveequipment to reduce the risk.
Private usesGeneral workplace safety legislation that callsfor user training and controls already appliesto Class 3B and 4 systems, and this is wellestablished in practice. However, as morepowerful lasers become affordable for privateuse, there is an urgent need in most countriesto define the legal and practical implicationsof private laser use. For instance, 50mW con-tinuous-wave green lasers are already mar-keted for private laser shows, in which thepatterns tend to involve the beam resting for afew seconds. These products feature all of therequirements of the laser safety standard
LASER SAFET Y
22 OLE • Apri l 2004 • optics.org
Products containing lasers, and some LEDs, shouldcarry a classification warning label but it can bedifficult to decide how classes should be assigned.
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and the CE mark based on the low voltagedirective, but are certainly not appropriate tobe sold to the general public. Users wouldhave to install the system at a height at whichmaximum exposure limits are not exceeded –this is usually 6 m above the ground.
It follows that such a product, even if itmeets all the requirements of the laser safetystandard and the manual tells the user toobserve national safety regulations, is notappropriate for the intended use according togeneral product safety legislation.
Likewise, the hazards of lasers can beincreased by misapplication of the standard.For instance, a green laser pointer with aQ-switched Nd:YAG laser might be desig-nated as a Class 2 source, based on its aver-age power of 1 mW. However, the peak powerof such devices is much higher, meaningthat they should actually be classified asClass 3R. They are also not really appropriatefor use by members of the general public.
When the private use of lasers is regulated,however, it is possible for both Class 3B and
Class 4 lasers to be safe in practice and to beused without special training and, in manycases, without eye protection. Examplesinclude laser lawnmowers and laser hairremoval systems, of which prototypes haveemerged recently. These are designed for safeuse and include safety features such as auto-matic detection of whether an appropriate“target” is in place. It would unnecessarilyhamper laser technology to restrict the pri-vate use of lasers to Class 2 and below.
Considering the whole pictureThese examples show that the safety classifi-cation of a laser product is only one of manyfactors that contribute to the safe use of suchdevices. It is important for the manufacturerand, in many cases, the user to perform a riskanalysis and minimize the risk by modifyingthe design of the product or adding othersafety controls. While the ambiguity in theclassification system is not entirely satisfac-tory, no system can realistically account forthe specific risk presented by every product.
The standards committee recognizes thatthe classification system is relatively compli-cated and that the information provided onthe labels does not always reflect the mean-ing of the classes appropriately. To improvethe situation, a standards project was set uplast year with the aim of reducing the com-plexity of laser safety labels and movingmore detailed information into the manual.
The long-term challenge for the lasersafety community is to provide standardizedtests which are prescriptive in nature but notover-restrictive. It is also important to pro-vide a classification scheme that is not toocomplex but still fully characterizes the haz-ard. The tendency in standardization is todecrease the level of worst-case assump-tions. However, this would also increase thenumber of potential situations in which agiven product of a certain class might bemore hazardous than its class suggests.
There is no ideal solution to this challenge,but manufacturers can help by recognizingthat, in addition to ensuring correct classifi-cation of their product, it is important tocarry out a risk analysis. It is also crucial thatthey give the user complete and detailedinformation on the risks associated withtheir product in the different modes of use –and even in situations of misuse. ■■
Karl Schulmeister is head of the accredited test housefor laser and optical radiation safety at SeibersdorfResearch, Austria. He is secretary of the workinggroup responsible for IEC 60825-1, associate direc-tor of Division 6 of the CIE for lamp safety standardsand member of the ICNIRP “Optical radiation”standing committee. He is co-author of Laser safety(Institute of Physics Publishing).
LASER SAFET Y
OLE • Apri l 2004 • optics.org
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It is hard to imagine that optical fibre – thebasis of virtually all modern communicationtools – could one day become obsolete. But itmay happen sooner rather than later, thanksto a new type of optical waveguide that isgrowing in popularity and providing anattractive alternative for several applications.
In the last five years three new start-upcompanies have been founded to commer-cialize the technology and the fibre giantsCorning and Mitsubishi Cable are also activein the field. The focus of all this attention isphotonic crystal fibre (PCF), a waveguidethat resembles standard silica fibre but withone very important difference – its claddingcontains an array of micron-sized holes run-ning along its length. The big attraction isthat by varying the size and location of theholes, the fibre’s mode shape, nonlinearity,dispersion and birefringence can reach val-ues that are not achievable in conventionalfibres. PCFs come in two varieties: solid corefibres (also known as index-guiding fibres)and hollow core (bandgap guiding).
Like conventional fibres, index-guidingPCFs confine light inside a solid core by totalinternal reflection thanks to a cladding thathas a slightly lower index of refraction. Bycontrast, bandgap-guiding PCFs rely on anentirely new mechanism for transmittinglight. Light is trapped in the core not by totalinternal reflection, but by a photonic bandgap(PBG) in the cladding that acts like an insula-tor for light. The PBG cladding is made withhundreds of periodically spaced air-holes in asilica matrix, typically arranged in a honey-comb-like pattern. Because the guiding is nolonger dependent on the core’s refractiveindex, it becomes possible to create fibres thatguide light in an empty or gas-filled core.
First demonstrationsOne of the first pioneers of PCF is Philip Rus-sell of the University of Bath, UK, who in1995 succeeded in making fibres with a pho-tonic crystal structure, and then in 1999demonstrated the first hollow-core PCFs thatguided light in an air core. He is now chieftechnology officer of BlazePhotonics, a com-pany in Bath which was established to com-mercialize PCF and is now selling dozens of
different types for a wide range of uses. One application is the generation of a
supercontinuum (broadband “white light”)that can be guided down the fibre. At thestart of the year Blaze launched a new PCFthat is specially optimized for converting theoutput of Nd3+ microchip lasers into such anoptical supercontinuum. The supercontin-uum can span an octave or more in wave-length, providing a broadband output in asinglemode fibre with a spectral brightnessmore than 10 000 times that of the Sun.
Blaze says this combination of microchiplaser with PCF provides a high-performancealternative to conventional broadbandsources such as lamps and superluminescentLEDs. Its applications include testing the spec-tral response of optical communicationsequipment, optical coherence tomography(OCT), multi-photon spectromicroscopy andchemical sensing, for which a high bright-ness over a large spectral range is paramount.
“PCFs have now clearly moved from beinga scientific curiosity to becoming a technol-ogy that is the preferred solution in a rapidlygrowing range of applications,” said HendrikSabert, vice-president of R&D at Blaze.
He added: “In hollow-core PCF we havenow demonstrated that more than 99% ofthe light can propagate inside the hollowcore and cladding holes, and theoreticalresults show that this may be improved tomore than 99.8%. Moreover, we can nowfabricate these fibres for the entire wave-length range from the visible to the near-infrared, say, from 440 to 2000 nm.”
Such fibres may prove especially useful forshort-pulse and high-power delivery withapplications ranging from micromachiningand fuel ignition to in vivo multi-photonabsorption spectroscopy. In addition, as PCFdoes not suffer from the bend-loss associatedwith normal fibre it should be easy to integ-rate into endoscopes or machining heads.
“Although there is still much work to bedone we are confident that hollow-core PCFcan deliver much higher power levels thanconventional fibre,” said Sabert. “With non-linearity and material dispersion virtuallyabsent, PCF can, for example, guide 100 fspulses of some hundreds of kilowatts of peak
power at 800 nm. This is ideal for the deliveryof ultra-short pulses from Ti:sapphire orNd3+:glass lasers.”
The Bath-based firm is not the only enter-prise trying to commercialize PCF. In 1998,Yoel Fink – then a graduate student at theMassachusetts Institute of Technology (MIT)– discovered a way to fabricate a perfectdielectric mirror. His mirrors use dielectriclayers of varying thicknesses to reflect lightat a range of wavelengths coming from allangles of incidence.
Fink realized that such an omnidirectional“perfect mirror” could be used as a cladding
A new type of optical fibre that rewrites the rules forguiding light is now coming of age. Rob van den Berg talksto three start-ups that are busy exploring the commercialpotential and applications of photonic crystal fibre.
Photonic fibre finds OPTICAL FIBRE
26 OLE • Apri l 2004 • optics.org
Top left: a set of four microscope images of a selection of solid codictates the fibre’s optical characteristics. Top right: the Crystal generation of broadband light known as a supercontinuum is one
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for an optical fibre that potentially has a verylow transmission loss. Excited by thisprospect, he established OmniGuide Com-munications of Cambridge, Massachusetts,to commercialize his work. The main break-through came at the end of 2002 when Finkand his MIT collaborators showed that it ispossible to make a hollow-core fibre for guid-ing 10.6 µm infrared light from a CO2 laser –something that simply isn’t possible withstandard silica fibre.
According to OmniGuide’s business devel-opment and product manager Gregor Delle-mann there is a big potential market for fibre
delivery of CO2 laser light, especially in themedical and materials processing fields. Onepotential application is the treatment ofpatients suffering from lung cancer: “TheCO2 laser is a very precise cutting tool. Withthe help of our fibre, doctors would be able toget the laser light into the upper part of apatient’s lung to selectively remove cancer-ous tissue that is blocking the larger air-ways,” explained Dellemann. “Because of itsprecision there would be substantiallyreduced risk of penetrating the lung tissueitself while cutting away the tumour.”
For metal processing applications muchhigher power levels are required, which arecurrently out of reach as the absorption andscattering losses inevitably lead to fibre fail-ure. Dellemann is confident, however, thatthis problem can be solved by optimizing thedesign of the fibres.
A third start-up that is busy in the field isCrystal Fibre of Lyngby in Denmark, whichclaims to have been the first commercial sup-plier of PCF. Its sales manager Rene Kris-
tiansen now sees a growing demand forsolid-core PCF, especially for double-cladfibres which convert light from multimodediodes into a high-quality singlemode beam.
“It is a way of converting cheap photonsinto high-quality photons,” explained Kris-tiansen. “Traditionally, double-clad fibreshave been made as step-index fibres of differ-ent materials – most typically with a polymerouter cladding. With the PCF technology, thefibres can be made of all silica.”
As for its most recent success, at the Opti-cal Fiber Conference (OFC) in Los Angeles inFebruary, a partnership between CrystalFibre and the California Institute of Technol-ogy demonstrated an air–silica Bragg fibre.The design comprises three concentricair–silica rings that confine the light in a hol-low core. According to Crystal Fibre, the fibrehas the potential to break the current losslimits for guiding singlemode light withoutpolarization mode dispersion – a trouble-some effect that degrades optical communi-cation systems.
In fact, in spite of all the current activity,the real moneyspinner for PCF will probablybe in telecoms, simply because of the lengthsof fibre involved. However, to be successfulthe loss level of PCF must be reduced to lessthan that of conventional fibre. Althoughthis is a tough challenge, steady progress isbeing made. Index-guiding PCFs with anattenuation of less than 0.3 dB/km at1550 nm have already been demonstratedby NTT of Japan at last year’s European Con-ference on Optical Communication. Butsince most of the light travels in the solidcore, loss is ultimately limited to the loss ofthe bulk material (0.2 dB/km), which is thesame situation as for standard silica fibre.
As hollow-core fibres do not suffer fromthe same limitations there is optimism thatthey may provide a lower loss solution, butthere is still much work to be done. Cur-rently, the lowest light loss for a hollow corefibre – 1.7 dB/km, presented by BlazePho-tonics at OFC 2004 – is still an order of mag-nitude higher than that of the bestconventional fibres.
“It is quite possible that hollow-core fibreswill ultimately achieve losses well below thatof conventional fibres,” said Sabert. “But atthis point, it is certainly fair to say that no-one knows where the limits really are.” ■■
Rob van den Berg is a freelance science journalistbased in the Netherlands.
27OLE • Apri l 2004 • optics.org
its first applications
ore and hollow core PCFs. The precise arrangement of the holesFibre team inside their fabrication plant. Bottom left and right:
e potential application for PCF.
For both BlazePhotonics and Crystal Fibre thestarting point for making PCF is to create amacroscopic glass preform with the samestructure as that required of the final fibre, albeiton a larger scale. One way to do this is to stackhundreds of silica capillary tubes and rods byhand into a structure with the appropriatepattern of holes. The hollow core is made byreplacing one or more of the capillaries by ahollow tube. This preform is then introduced intothe furnace of a fibre drawing tower.
At the temperature at which silica softens –about 2000 °C – the preform is fused togetherand drawn down to a size of 1–10 mm with airholes of 0.05–0.5 mm. After an additionalsleeve tube has been added this “cane” isdrawn down to its final dimensions in a seconddraw step. Typical hole sizes in the final fibrerange from 0.5 to 5 µm, with hole spacing inroughly the same range.
OmniGuide’s dielectric fibres are made in asimilar way. The fibre preforms are producedby evaporating a chalcogenide glass (As2Se3)onto a polymer sheet (polyethersulphone),wrapping the film around a glass mandrel andconsolidating the layers under heat. After theglass mandrel has been etched out the pre-form is ready to be drawn.
How PCF is made
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Careful mount designkeeps mirrors aligned
BUYER’S GUIDE
29OLE • Apri l 2004 • optics.org
When it comes to constructing opticalinstruments and performing experiments, aset of mounts that can reliably hold a mirrorand precisely adjust its alignment is essential.Although there are many different modelson the market, all mirror mounts fall intoone of three basic categories – kinematic,flexure and gimbal (see box). Of these, thekinematic mount is the most common.
All mounts are capable of making twotypes of angular adjustment which arerequired for beam steering – tip and tilt, alsoknown as pitch and yaw. Some also providelinear translation along the optical axis.
The most appropriate mount for yourneeds can be determined by assessing a fewsimple criteria. The most important consid-erations are the precision of the application,the degree of adjustment required and thelong-term stability needed. Performance inthese areas must then be balanced with yourbudget. Another issue is whether the optic isto be set and left, or adjusted frequently.
Kinematic mountsKinematic mounts consist of a front plate tohold the optic and a base that attaches to amounting post or an optical table. In manykinematic models the front plate is held inplace by a series of springs. The number andstrength of these springs depends on thesize of the mount and the weight of theoptic to be held.
It is important that the design of the baseand front plate limits any unwanted move-ment while still allowing manual adjust-ment. A carefully designed mounting basecan also aid alignment by providing moreoptions for the mounting position. A truekinematic mount will constrain each of itssix degrees of freedom (x, y, z, roll, pitch andyaw) to offer maximum stability and pre-vent any unwanted motion that could mis-align an optic.
To achieve this, kinematic mounts havethree points of contact: a cone; a v-groove (ortwo parallel rods); and a flat surface (plane).Most often, the cone interfaces with a metalball in order to constrain motion in the x, y
and z directions but allow pitch and yaw rota-tions. By contrast, the v-groove and the planeinterface with a spherically-tipped drivescrew. The drive screw is often made from ahardened stainless-steel ball that is attachedto a thread. The v-groove is designed to con-strain pitch and yaw movements but allowlinear translation, while the third contactpoint, the plane, constrains roll.
Adjusting the two drive screws that inter-act with the v-groove and the plane allowsthe tip and tilt of the mirror to be preciselyadjusted to steer the reflected light beam.
Some kinematic mounts achieve lineartranslation along the mirror’s optical axis byreplacing the hardened steel ball that inter-faces with the cone with a spherically-tippeddrive screw. Adjusting all three drive screws
together enables the mirror to be moved asmall distance (perhaps up to 10 mm or so)along the optical axis.
Similar in design to the kinematic mount,flexure mounts have two drives that usesolid flexure springs to constrain unwantedmotion instead of the cone, groove and flatof the kinematic design. Range of traveltends to be less than for kinematic mounts.Flexure designs may typically have a travelof ±5° whereas kinematic models can givemore than 10°.
Both kinematic and flexure mountsrotate about a point that is not directly onthe surface of the mounted optic. Thismeans that when a rotation (pitch or yaw)adjustment is made it results in someunwanted translation. As mentioned pre-
Picking the right mirror mount for your optical application could save you from hours offrustration. Colin Freeland gives a round-up of the different types of mount available.
Z
Y
X
θy pitch
θx roll
θz yawv-groove
yawadjuster
pitchadjuster
cone andsteel ball
mirror holder
flat
(optical axis)
Mounts explained: kinematic models such as the version above often have two knobs for making preciseangular (pitch and yaw) adjustments to a mirror’s alignment. Careful design minimizes drift.
Kinematic mount: A mount that uses theinteraction between a series of set screws anda cone, groove and flat surface to make angularand translation adjustments.
Flexure mount: A mount that uses a seriesof solid springs to constrain movement of thefront plate holding the mirror. As the springs arevery good at constraining unwanted twist, thisgives improved positioning accuracy.
Gimbal mount: Both kinematic and flexuremounts suffer from slight unwanted translation
because the axes of rotation are not centred onthe surface of the mirror.
In contrast, a gimbal mount provides angularadjustment without any translation. It isgenerally used for the most precisebeam-steering applications.
Resolution: The smallest linear or angularadjustment that a mount can make.Resolutions down to 0.1 arcsec are possiblewith top-quality mounts equipped withdifferential actuators.
Jargon buster
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Ellio
t Sc
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viously, some mounts have three adjustersso that this can be accommodated. In otherdesigns, the rotation point is moved closerto the surface of the mirror, creating lesstranslation. Where this linear motion can-not be tolerated, gimbal mounts should beused because they provide true rotationwithout any translation. Because they havetheir rotational axes centred about the frontsurface of the mirror, the optical pathlength remains constant during angularadjustments.
MountingOnce inside the mount, the mirror rests on atwo-line contact, which is machined into themount and sometimes has soft inserts to pro-tect the mirror. A set screw, ideally with a softtip made from nylon, for example, then holdsthe mirror in place.
Most mounts have the optic inserted fromthe front, but in certain configurations it isuseful to be able to mount from the back.This has the benefit that if you are switchingan optic for one of a different thickness, the
mount position need not be adjusted becausethe front of the mirror stays in the sameplane. Mirror-mount front plates come inmany forms, with some models also allowingthe mounting of transmissive optics such asbeamsplitters. Mounts with offset optics areavailable where the mirror or beamsplitterhas to be in a confined position.
Material selectionAluminium is the most commonly used mat-erial in optomechanical mirror mounts. It iseasily machined and can be anodized to givea harder surface finish. Black anodizing canalso reduce unwanted surface reflections.
Using a steel adjustment screw in an alu-minium mount would produce excessive fric-tion, leading to poor adjustment resolutionand long-term wear. As a result, for special-ized applications such as use in a vacuum, itcan be preferable for the body of the mirror
mount to be made of brass or stainless steel.An adjuster can then be threaded directlyinto the body of the mount. This is particu-larly useful where space is limited and themounts are very small. This is normally onlyused in OEM applications.
However, for most commercially availablemounts, a threaded brass bush or somethingsimilar is mounted into the aluminium body.A stainless-steel threaded adjuster can thenbe used with minimal lubrication. It is thequality of the machining of the stainless-steel adjuster, the closeness of thread fit tothe brass bushing and the choice of lubrica-tion that most affect the feel of the mountand its stability.
To be able to achieve the theoretical reso-lution of the mount the user must be able toeasily set the adjuster. The feel of the adjusteris crucial for fine-tuning the position. This
BUYER’S GUIDE
30 OLE • Apri l 2004 • optics.org
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A small screw with a soft tip is often used to hold amirror in the mount’s central aperture.
is where the methods and materials used inmanufacturing have the most effect on thecost and performance of the mount.
If there is end-float or “play” in the threads,you will not be able to position as accuratelyas a precision-lapped thread. There are alsoimplications for long-term stability. The lubri-cant used also has an effect on the feel of theadjuster. High-quality threads require littlelubrication, but economy mounts may use athick grease to fill gaps in the threads.
One low-cost method of improving a
mount’s stability and making it less suscepti-ble to long-term drift or accidental misalign-ment is to have locking mechanisms on theadjusters. Unfortunately, locking mecha-nisms will always slightly move the mount’salignment but manufacturers try to mini-mize this in different ways. Higher-qualityadjusters do not really need locking mecha-nisms because the play on the threads is min-imized and prevents gradual drift.
Adjusters may come with removableknobs and hex key drives, which are useful as
the user need not touch the mount directly.They have the added benefit that when themirror is adjusted the knob cannot easily beturned by mistake. They also take up lessspace in an instrument or on a bench wheremany mounts are positioned.
ResolutionThe angular resolution of a mirror mount isexpressed in degrees or arc seconds (there are3600 arc sec per degree). The stated resolu-tion can be somewhat confusing as differentmanufacturers adopt different descriptions,but fundamentally the resolution of a mirrormount is determined by the smallest move-ment possible on the adjuster. An acceptedstandard is that the smallest rotation of theadjustment screw that can be made is 1°.Therefore the resolution is determined by the
pitch of the thread (the number of turns perinch or millimetre) and the smoothness ofthe adjusters.
Metric threads are described as 0.25 pitch,for example (0.25 mm per turn), whereasimperial threads are expressed in TPI orthreads per inch. A common specification is80 TPI but higher-precision mounts use100 TPI – the same as 0.25 mm pitch thread.
A typical 1 inch mirror mount with100 TPI or 0.25 pitch adjusters would havea resolution of 2 arc sec. For the highest-res-olution applications differential actuatorsare available. Where differential adjustersare used, resolutions down to less than0.1 arc sec are achievable.
Most manufacturers offer a range startingwith economic kinematic mounts with sim-ple adjusters, and continuing up to the mostexpensive mounts with high-precision hand-lapped threads. Depending on the quality ofadjustment required and the long-term sta-bility of the optical set-up, a suitable mirrormount should be available for everyone. ■■
Colin Freeland is the photonics product manager atElliot Scientific Limited in Harpenden, UK. The firmis a manufacturer and distributor of positioningequipment. For more information visitwww.elliotscientific.com.
BUYER’S GUIDE
32 OLE • Apri l 2004 • optics.org
“If there is any‘play’ in thethreads you willnot be able toposition asaccurately.”
Since unveiling its plans to host a Europeanoptics event, SPIE has been busy puttingtogether a comprehensive technical pro-gram, an exhibition and a series of specialevents that will see Photonics Europe launchwith a bang. The day of reckoning, bringingto an end months of curiosity for members ofthe optics community, is April 26.
“Our initial goal for Photonics Europe wasto build a high-quality technical program.The meeting is not exhibit-driven,” said ScottWalker, SPIE’s project manager for the event.“This is an opportunity for a lot of people toattend a large technical meeting in Europe.”
Having attracted around 1000 papers, thetechnical conference will certainly not dis-appoint. It boasts sessions on everythingfrom photonic crystal materials to VCSELs,optical sensing and organic optoelectronics.Running alongside the conference, SPIE hasalso managed to attract more than 120exhibitors, ensuring that there will beenough going on to keep both academic andindustrial attendees busy.
Walker anticipates that between 1800 and2000 people will attend Photonics Europeand says that the Strasbourg conventioncentre will be a hive of activity. “Every roomwill be filled, the hallways will be packed andpeople will be bumping into colleagues fromall around the world,” he said. “You’ll get areal feeling of community.”
So what exactly is in store for delegatesattending the technical sessions? The firstday, Monday 26 April, kicks off with a “Hot
Topics” plenary session dedicated to up-and-coming areas of photonics.
Hugo Thienpont of Vrije University in Bel-gium is one of the general chairs of Photon-ics Europe. As he explains, the all-day HotTopics session features a list of top speakerswho will be discussing the latest break-throughs in their fields: “The speakers willpresent the breakthroughs in a tutorial man-ner so that everyone gets an overview of thearea. We have tried to select them in such away that there is a representative talk fornearly every topical conference.”
The topical conferences will begin the fol-lowing day. Thienpont and colleagues haveworked hard to put together a balanced line-up that ensures that rooms are full and thatindividual conferences target a specific area.“I did not want the conferences to overlap,”Thienpont explained. “Those people whowant to stay with their topic can go to a con-centrated meeting and others have a goodvariety to choose from.”
Global attendanceDelegates from a total of 44 countries will bepresenting papers. “One thousand contribut-ing papers is an overwhelming response forthe very first conference,” said Thienpont.“The quality of the papers is extremely high.We have tried to select the very best papers fororal presentation and scheduled the rest asposters. We have had to be far more severethan usual.” All of the oral presentation timeslots are now full and 260 applications have
34 OLE • Apri l 2004 • optics.org
When: 26–30 April 2004 Where: Palais de la Musique et des Congrès deStrasbourg, FranceTechnical conferences: 27–30 AprilSpecial events, professional developmentand short courses: 26–30 AprilExhibition: 27–29 AprilExhibition opening hours:27 April 10.00 a.m. to 5.00 p.m.28 April 10.00 a.m. to 5.00 p.m.29 April 10.00 a.m. to 2.00 p.m.
What’s on: 26 April● Hot topics in photonicsThis is a one-day plenary session focused on
the most important developments in photonics.Topics under discussion include organic lasermaterials, VCSELs, three-dimensional photoniccrystals, microwave and terahertz photonics.● Professional development and short coursesbegin.
What’s on: 27 April● Free-to-attend exhibition opens its doors● Technical conferences kick-off● Doing business in the USA? Strategies for suc-cessfully setting up a US operationThis free-to-attend half-day workshop runningfrom 9.00 a.m. to 12.00 noon outlines theopportunities, challenges and pitfalls of
entering the US optoelectronics and photonicsmarketplace. ● Welcome receptionAll conference participants are invited to attendthe welcome reception at Le Palais Universitaire,which will be held between 7.00 and 8.30 p.m.
What’s on: 28 April● Photonics Europe business programA half-day event running from 2.00 to 6.10 p.m,talks will include growth markets for MEMSmedical products, an update on the Frenchbiophotonics market, photonics in theautomotive industry and an update on theSEMATECH roadmap for the semiconductor
ESSENTIAL INFORMATION
PHOTONICS EUROPEHIGHLIGHTS 34 PRODUCTS 37
The Palais de la Musique et des Congrès (top left)is only five minutes by tram from Strasbourg’s oldtown and cathedral.
Just what lies in store for delegates at the first Photonics Europeevent being held in Strasbourg between 26 and 30 April? Over thenext seven pages, we bring you a preview of the event as well as alook at some of the new products making their debut.
been assigned a poster presentation.One point to note is that there are no topi-
cal conferences covering optical communi-cations. “We really tried to avoid opticaltelecoms,” explained Thienpont. “The Euro-pean Conference on Optical Communicationis very good in Europe and we will not startany competition there. I know optical tele-coms is a big part of European research, butwe wanted to give something else.”
The technical conference is supplementedby a series of special events (see box) and theexhibition. Both Walker and Thienpont agreethat Thursday’s session on the EuropeanCommission’s Sixth Framework is a highlightof the programme. The session will feature aseries of talks given by the co-ordinators ofprojects that have recently received funding.
“We want to make this a meeting placewhere people see what the Commission hasto offer, what Europe has to offer, what net-working opportunities are available andwhere the critical mass of researchers is for aparticular topic,” explained Thienpont.
If you find that your diary is full on Thurs-day afternoon, the Commission is also givinga talk at Monday’s Hot Topic session on pho-tonics technologies in its Information SocietyTechnologies program.
Attracting academic attendees to Photon-ics Europe has always been SPIE’s priority,but it is also keen to bring in visitors withcommercial interests, such as companyexecutives and venture capitalists. To helpachieve this, SPIE has put together a half-daymeeting called the “Photonics Europe Busi-ness Programme”.
Walker reveals the reasoning behind theevent: “We want to say to people: ‘Come toPhotonics Europe and you will see where theresearch is heading and also the huge markets
that are being created from this research. It’s ameeting that is about research and turningthat research into products and business.”
Commercial opportunitiesThe business programme, which runs onWednesday afternoon and which all dele-gates can attend free-of-charge, consists ofsix 45 minute presentations covering vari-ous aspects of photonics. For example,Berthold Hopf from DaimlerChrysler will bediscussing the challenges and opportunitiesfor photonics technologies in the automo-tive industry. Attendees will also hear aboutthe latest changes that International Semat-ech has made to its roadmap for the semi-conductor industry.
While the main exhibit caters for compa-nies that have established a presence in theoptics community, Photonics Europe willalso feature a Photonics Innovation Villagethat is intended to showcase the research ofyoung innovators, start-ups, entrepreneursand research groups.
“It could be a start-up or a spin-off withtwo or three people who do not have muchmoney, but have bright ideas that they wantto show people,” said Thienpont. “Or it couldbe innovators who have an idea but no com-pany, or simply research groups who want toshow what they are doing.” Booths for theVillage are free-of-charge, thanks to sponsor-ship from a local brewery.
Looking at the daily schedule for PhotonicsEurope, it is obvious that delegates are in forbusy but fulfilling days. “Photonics Europe iscomprehensive, and both commercial andscientific,” concluded Walker. “The underly-ing goal of this is to highlight all of theresearch that is being carried out in Europe. Ithink it’s going to be an exciting week.”
35OLE • Apri l 2004 • optics.org
industry.● Optics and Photonics Cluster eventRepresentatives from European clusters willdiscuss best-practice networking models,successful recruiting activities and how tomaintain membership levels, and will exchangeideas on going it alone without governmentalsponsorship. Starts 6.20 p.m.
What’s on: 29 April● VI Framework Overview Attendees at this half-day event from 2.00 to6.00 p.m will hear discussions on the SixthEuropean Framework Programme of researchand development. Project co-ordinators will be
presenting details of research activities thathave just received funding.● Photonics Innovation Village awardsEight awards will be presented in categoriesincluding “most creative photonics smartobject”, “most market-promising photonicssmart object” and “best photonics smart objectfor metrology”. 5.00 p.m. to 6.00 p.m.● Poster session 6.00 p.m. to 8.00 p.m.
What’s on: 30 April● National and transnational R&D projects andinitiativesA session running from 9.00 a.m. to12.00 noon that aims to bring together
researchers from across Europe. Five speakerswill highlight projects in the areas ofoptoelectronics and photonics that havereceived national funding.● MEDPHOT – optical methods for medical diag-nosis and monitoring of diseasesThis session will be the final EU networkworkshop on this topic under the FifthFramework. The workshop will focus on newdiagnostic instrumentation, transferring theequipment into industrial production andclinical studies. 2.00 p.m. to 5.00 p.m.
● Full program: http://spie.org/conferences/programs/04/epe
ESSENTIAL INFORMATION
Tourist attractions: SPIE has left Wednesday nightfree for delegates to explore and enjoy the sightsand sounds of Strasbourg.
SHOW PREVIEW
HIGHLIGHTS
Dichroic mirrorsOptarius
Optarius of the UK willbe exhibiting its rangeof dichroic mirrors atPhotonics Europe. Theproducts are part of thefirm’s Optics for Lasersline, which includes
tuning mirrors, cavity mirrors, Brewster windowsand polarizing optics.
Dichroic mirrors separate or combine theconstituent parts of an optical beam accordingto wavelength. The mirrors consist of a dielectriccoating on a precision glass or fused silicasubstrate. According to Optarius, its mirrors canseparate lines as close as 80 nm anywhere inthe spectral range 200–2000 nm.
The company says the mirrors offer areflectance in excess of 99% and atransmittance in excess of 85%.www.optarius.co.ukStand 302
Medical illumination softwareLight Tec
Light Tec of France willbe demonstratingmedical illuminationdesign software at itsbooth. The TRACEPROsimulates a range of
medical systems including microscopes,endoscopes and medical lighting.
LightTec says that the software can simulatelight interaction with human tissues using achoice of phase functions; model energypropagating through human or animal tissue;and define any bulk scatter phase functionthrough user-defined DLLs.www.lighttec.frStand 610
SpectrometerOcean Optics
Spectrometerspecialist Ocean Opticswill launch itsHR4000CG-UV-NIRproduct at PhotonicsEurope. The device is a
composite grating spectrometer which gives aresolution of 0.5 nm (FWHM) anywhere in the200–1100 nm range.
Based on a proprietary Landis grating and anorder-sorting filter, the spectrometer is said to be
ideal for applications such as laser wavelengthcharacterization and absorbance of gases, aswell as determining atomic emission lines.
The plug-and-play device also featuresuser-programmable I2C and SPI buses andautomatically selects between USB 1.1 and USB2.0 protocols. Ocean Optics is currently sellingthe HR4000CG-UV-NIR for €3799.www.oceanoptics.comStand 500
Fibre laserunique-m.o.d.e
unique-m.o.d.e ofGermany will beunveiling its 491 nmup-conversion fibrelaser. Offering up to10 mW of output power
in a TEM00 beam, the company says that theUMFL491 laser is ideally suited to the life-scienceinstrumentation market and applications such asconfocal microscopy and flow cytometry.
The laser contains an active fibre that ispumped by a laser diode. The fibre converts theinfrared pump beam into visible light, whichresults in a compact and robust laser.
The company says its fibre laser is 50 timesmore efficient than, and has a footprint fivetimes smaller than, traditional argon-ion lasers.www.unique-mode.comStand 300
Nanosecond tunable laser Ekspla
The NT340 tunablelaser system fromEkspla combines ananosecond opticalparametric oscillatorand a Q-switched pumplaser in a singlecompact housing.
The system featuresan output pulse energy of up to 30 mJ in thevisible, a linewidth of less than 5 cm–1 andhands-free wavelength tuning across420–2300 nm. Pulses are typically a fewnanoseconds in duration and an option toextend operation down to the ultraviolet(210 nm) is available on request.
Ekspla says that OPO pump-energymonitoring, zero warm-up time and othervaluable features ensure easy maintenance andreliable operation of the system. The laser canbe computer-controlled through an RS-232interface with LabView drivers. A remote-controlpad is also available.
Applications include laser-inducedfluorescence, photolysis, photobiology, remotesensing, LIDAR and many others. www.ekspla.comStand 1009
SHOW PREVIEW : PRODUCTS
37OLE • Apr i l 2004 • optics.org
The Photonics Europe exhibition runs from27–29 April and is free to attend. Over thenext five pages we bring you a look at someof the new products that will be on display.
Nd:YAG laserQuantel
Quantel is introducinga new Q-switchedNd:YAG laser atPhotonics Europe. TheBRIO is equipped withmodular harmonicgenerators and adouble-pulse version is
available for particle imaging velocimetry. Thelaser’s pulse energy exceeds 120 mJ at awavelength of 1064 nm. Pulse duration is 5 nswith a 20 Hz repetition rate.
The French laser maker says the BRIO’s designfocuses on reliability, ease of maintenance, gooduser interface and high performance. www.quantel.frStand 216
Visible laserBFi OPTiLASPicarro has released a cyan laser that offers20 mW at 488 nm from a compact device thatis approximately 10 times smaller than mostother air-cooled argon lasers. The laser isavailable in Belgium, France, Italy, Luxemburg,Portugal, Spain and the Netherlands throughBFi OPTiLAS International.
BFi says that the laser has been developed inclose collaboration with a number of bioscienceinstrument OEMs to ensure that it meets theneeds of users. Applications include DNAsequencing, haematology, flow cytometry,capillary electrophoresis and reprographics.
According to BFi, the laser’s beam quality andpower stability, together with its lifetime of morethan 20 000 h and its compact size, make it anideal replacement for air-cooled argon lasers.
More wavelengths based on the sametechnology will be introduced soon.www.bfioptilas.comStand 515
Power measurement systemsSphereOptics
A selection of systemsfor measuring the totaloutput power of lasersand laser diodes will beon display atSphereOptics’ booth.
The firm says that its systems are available withvarious detectors to suit a range of applications.
Each system comprises an integrating spherewith a mounting post and base, a detectorassembly and a picoammeter. Customers canchoose 2, 4 or 6 inch diameter spheres coatedwith the company’s Optowhite or Zenith interiormaterials. SphereOptics adds that its systemscomply with national laboratory standards.www.sphereoptics.comStand 107
SHOW PREVIEW : PRODUCTS
Europe: Paul Höß KGP.O. Box 950240, 81518 München, GermanyPhone: +49 (0)89 652029Fax: +49 (0)89 654817E-mail: [email protected]
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U.S.A.: Stanford Computer Optics, Inc.780 Cragmont Avenue, Berkeley, CA 94708, USAPhone: +1 (510) 527-3516Fax: +1 (510) 558-9582
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38 OLE • Apr i l 2004 • optics.org
Optical design softwareBreault Research Organisation
Users of BreaultResearchOrganisation’s ASAPsoftware should pay avisit to the company’sbooth at Photonics
Europe, where Version 8 of the program will bedemonstrated. This latest release of the opticaldesign software is said to perform handlingdesign, analysis and virtual prototyping.
According to Breault, ASAP 8.0 combines 3Dmodelling techniques with non-sequential raytracing and features both incoherent andcoherent beam-propagation algorithms. It alsobrings together geometrical and physical opticswith full three-dimensional models of opticaland mechanical systems.www.breault.comStand 406
Plasma monitoring systemMikropack
Mikropack will beshowcasing its high-resolution fibre-opticplasma measurementsystem at its booth.Using a 2048 pixel CCD
and fast-acquisition electronics, the firm saysthat its PlasCalc-2000 acquires plasma lightemission from 200 to 1100 nm in 3 ms.
The instrument includes a 14 bit D/Aconverter with four analogue, four digital inputand four digital output channels. The fouranalogue channels convert the plasmaspectrum into voltage signals from 0 to 10 V.
All components are built into a small desktophousing, which features a USB interface toconnect to personal computers or notebooks.Mikropack can supply the PlasCalc with variousfibre lengths, collimating optics and differentvacuum feed-throughs.www.mikropack.deStand 401
CCD cameraPCO Imaging
Germany’s pco.imagingwill be displaying itssensicam em camera atPhotonics Europe.Using on-chip
multiplication, the camera is said to have anelectron multiplication gain of up to 800 and aread-out noise of less that one electron rms at again greater than 200.
The camera uses a thermoelectric cooler,which can reduce the temperature of the 12 bitdigital CCD to –16 °C. With exposure timesranging from 50 µs to 1 h, the company claimsthat the system is ideal for extremely low-level-
light applications.The firm adds that its sensicam em has a
resolution of 1000 ×1000 pixels and aquantum efficiency of up to 65%.www.pco.deStand 211
Optical filtersOmega OpticalOmega Optical says that its new patent-pending3rd Millennium filters are hermetically sealed toprotect the dielectric coatings. The filterassembly does not use polymer adhesives, tominimize the risk of photon damage and thermalinstability. According to Omega, the result is alonger filter life, increased transmission,reduced parasitic fluorescence and significantlyreduced transmitted wavefront distortion.
The filters are currently available as stockbandpass, longpass and shortpass assemblies.They are also available as fluorescencemicroscopy filter sets for common fluorophores.
The filters use Omega’s proprietary ALPHAtechnology, which allegedly produces edgeslopes 10 times steeper than industry standardFabry–Perot designs. Omega says that as aresult, passbands can be made wider and stillachieve the blocking requirements of narrower,less steep designs. For example, it claims that a20 nm bandpass ALPHA filter has twice thethroughput of a 10 nm Fabry–Perot bandpassfilter, as well as better spectral purity at OD4. www.omegafilters.comStand 404
Pulsed laser diodesLaser Components
The Laser ComponentsGroup will usePhotonics Europe toshowcase its latesthigh-power, pulsedlaser diodes (PLDs).Produced at the firm’sCanadian facility, thediodes emit at 905 nmand 1550 nm and are
said to be suitable for applications such asrangefinders, security scanners and test andmeasurement systems.
Thanks to an efficiency of 1 W/A, stackedemitters can allegedly produce a peak power of120 W and pulse lengths of 200–1000 ns. The905 nm PLDs are offered in TO-18, 5.6 mm or9 mm housing as well as 8032 Coax or as achip-on-ceramic mount.
Laser Components says that the 1550-seriesis best suited to eye-safe rangefinding. Single orstacked emitters are available with a peakpower of 50 W. Custom-designed devices andother wavelengths are also available.www.lasercomponents.co.ukStand 314
SHOW PREVIEW : PRODUCTS
39OLE • Apr i l 2004 • optics.org
Laser diodesPhotonic Products
Photonic Products ofthe UK will bedisplaying its range ofthermoelectricallycooled laser diodemodules at its booth.Producing an ellipticaloutput beam, thediodes are availableemitting 50 mW at
405 nm, 15 mW at 440 nm and 4 mW at473 nm. The devices can be packaged in eithera 9 mm or a 5.6 mm package.
The firm says the diodes have been designedfor applications that demand consistency andrepeatability such as high-resolution printing,biomedical instrumentation and microscopy.
According to Photonics Products, prices havebeen reduced significantly across the completerange of laser-diode modules.www.photonic-products.comStand 405
MicroscopesPyser-SGIPyser-SGI will be showcasing its new range ofmagnifiers, portable microscopes, single- anddual-axis measuring systems, video inspection
systems and modular microscopes at PhotonicsEurope 2004.
The firm says that its Inspecta range ofproducts offer a superior solution to opticalinspection and measurement requirementsacross a wide range of manufacturing industries.From simple magnifiers with graticules to videoinspection and co-ordinate measurement, thePyser Inspecta range offers both standard andcustom-made products.
Also at Photonics Europe 2004 will be a widerange of imaging-related products, includingreticules, stage micrometers, calibrationstandards, resolution charts, gratings andprecision apertures.www.pyser-sgi.comStand 413
Optical parametric oscillatorsGWU
GWU-Lasertechnik saysthat it can now offer arange of opticalparametric oscillatorsand optical systemsbased on nonlinearcrystals such as BBO,
LBO and KTP, among others. The currentportfolio includes models with variouslinewidths, tuning ranges and beam parameters
to suit both scientific and industrialapplications.
The company’s midband system is speciallydesigned to suit analytical applications whereasits “uld” OPO offers excellent beam quality withthe very low divergence that is required for allapplications with long beam-path lengths.
GWU says that a new operating conceptallows fully automated calibration while a robustresonator design makes operation possible evenin harsh environments. www.gwu-group.deStand 110
Fibre laser kitIDIL
IDIL Fibre Optics ofFrance will present aneducational kit forconstructing a mode-locked fibre laser atPhotonics Europe. Thecompany says that the
new offering complements its large existingrange of fibre-optics kits.
The latest kit contains all the components thata student needs to build a 19 inch rack-mountedshort-pulse “figure of eight” fibre laser based ona nonlinear amplifying loop mirror.
Once constructed, the laser can be used togenerate and study short-pulse phenomena.IDIL says that by modifying different parameterssuch as polarization, dispersion or pumpcurrent, it is possible to study the optical andelectrical spectra of pulses, as well as thenormal mode-locking and soliton regimes. Thekit comes complete with a user’s manual forteachers which includes the theory behind thelaser, suggested experiments and exercises. www.idil.frStand 401
Pulse measurement systemNewport
Newport claims that itsnew UPM series ofultrashort laser pulsemeasurement systemscan completelycharacterize pulses,while being simple to
set up and align. The Grenouille device relies onthe frequency-resolved optical grating (FROG)approach and is able to capture time plots ofthe pulse’s intensity and phase as well as itsspectrum. Newport says that it will not becomemisaligned for the simple reason that there areno alignment knobs to turn. The UPM series isalso able to measure spatio-temporal distortionssuch as spatial chirp and pulse-front tilt –parameters that many systems cannot measure. www.newport.comStand 402
SHOW PREVIEW : PRODUCTS
40 OLE • Apr i l 2004 • optics.org
Spectrometer electronicstec5
tec5 of Germany hasdeveloped high-speedelectronics for acquiringdata from photodiodearrays andspectrometer modules.The system allows
acquisition of more than 1000 spectra persecond with a 16-bit dynamic range.
The company says that a read-out clock rate of11 Mpixel/s is possible for NMOS photodiodearrays and spectrometer modules, such as theZeiss MCS. In addition, Hamamatsu CCD sensorsof type S-703x or Zeiss MCS CCD can beoperated at 500 kHz by using the tec5 CCDpreamplifier and the fast tec5 converter boards.The data transfer is performed by a PCI or aUSB 2.0 interface. Software drivers and functionlibraries for use with the electronics are availablefor computers running Windows 2000, NT and XP. www.tec5.comStand 1007
DPSS laserLumera LaserThe STACCATO from Lumera Laser is amodelocked diode-pumped solid-state laserwith a regenerative amplifier and is capable ofdelivering power densities of several terawattsper square centimetre. The laser output is TEM00
beam quality and its 12 ps pulses have anenergy of up to 0.5 mJ.
Lumera claims that the STACCATO representsa breakthrough for micromachining applicationsand is one order of magnitude morecost-effective than ablation with femtosecondlasers. A repetition-rate of 100 kHz – about 20times that of amplified femtosecond systems –means that the STACCATO delivers higherthroughput and decisively lower cost per part.www.lumera-laser.comStand 1108
Beam profilerSpiricon
Spiricon’s LBA-700PCseries of beam profilerscan interface with bothanalogue and digitalcameras. On display atthe company’s boothduring the exhibition,the laser beam profileroffers an 8–16 bit
digital camera RS-422 interface and an 8–14bit A/D converter for analogue cameras.
The instrument comes with Spiricon’sUltracal camera baseline setting and full-featured software.www.spiricon.deStand 410
SHOW PREVIEW : PRODUCTS
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41OLE • Apr i l 2004 • optics.org
Extended-cavity diode laser systemSacher Lasertechnik
Sacher Lasertechnikhas added a newproduct to its TIGERseries ofextended-cavity diodelaser systems. The
latest product offers more than 1000 mW ofoutput power at 780 nm and is said to have atotal tuning range exceeding 20 nm. The devicealso boasts a small footprint, low energyconsumption and user-friendly handling.
Sacher says that the product has a linewidthof the order of 1 MHz; a sidemode suppressionbetter than 50 dB; and a diffraction-limited beamquality of less than 1.7 M2. The modehop-freetuning range is said to be up to 25 GHz.
Applications of the 1 W system include opticalcooling, trapping of rubidium andhigh-brightness Raman spectroscopy.www.sacher-laser.com
AutocorrelatorSpectra-Physics
Spectra-Physics hasintroduced thePulseScout, anautocorrelator that canallegedly measure laserpulse durations from20 fs to the picosecond
regime and wavelengths from 420 to 1600 nm.Supplied with two interchangeable detector
heads, Spectra says that its PulseScout canreliably measure pulse widths from bothlow-energy, megahertz repetition-rate oscillatorsand high-energy, low-repetition-rate amplifiers.
The product is also supplied with aspectrometer, which enables both temporal andspectral measurements of ultrashort laserpulses. The autocorrelation trace and spectrumcan be displayed on a computer monitor via anRS-232 interface.www.spectra-physics.com
DPSS laserCoherent
Coherent hasdeveloped what itclaims is the world’shighest-powerdiode-pumped TEM00
continuous-wave (CW)green laser. The US firmsays its Verdi-V18
delivers in excess of 18 W of 532 nm output,making it ideal for high-power materialsprocessing and scientific applications.
The V18 is said to have an optical noise of
less than 0.04% rms, measured from 10 Hz to1 GHz, and is pumped by Coherent’slong-lifetime aluminium-free active-area diodelasers. A closed-loop feedback system controlsthe pump laser wavelength.
“The V18 represents the world’s highestpower diode-pumped TEM00 CW green laser,”said Paul Somerville from Coherent. “This makesit a perfect solution for power-hungryapplications, such as pumping modelocked andCW Ti:sapphire and dye lasers.”www.coherent.com
Variable optical attenuatorLightconnectLightconnect of the US has introduced anultrafast multimode variable optical attenuator(VOA) for free-space optical (FSO)communications. The Fast VOA 3000 is said tohave a typical response time of 30 µs, making itideal for scintillation compensation.
One of the major challenges when developingFSO systems is scintillation, or atmosphericturbulence. According to Lightconnect, the FastVOA 3000 is the only multimode VOA availablethat can provide the necessary power levelcompensation at a fast enough rate to overcome
the effects of scintillation.The product is initially being offered in the
C-band, although the company says that otherversions can be developed according tocustomer requirements.www.lightconnect.com
RetroreflectorsEdmund Optics
High-tolerance corner-cube retroreflectors arenow available fromEdmund Optics (EO).The components aredesigned to return abeam back along its
original path, regardless of the angle of incidence. EO says that the retroreflectors provide a
1 arc sec parallelism between the incoming andexiting beams. A silver coating enhances theproduct’s reflectivity.
The products are packaged in a woodenstorage case and include an EO calibrationcertificate. Common applications for theretroreflectors are said to be optical metrology,gauging and alignment.www.edmundoptics.com
PRODUCTSIf you would like your company’s products to be featured in this section, please send press releases
and images to Jacqueline Hewett ([email protected]).
43OLE • Apr i l 2004 • optics.org
Positioning equipmentNewport
Newport of the US hasreleased the first twoproducts of its NewStepseries of positioningproducts. Designed toprovide low-costsolutions, the products
are the NewStep controller (NSC100) and theNewStep Actuator (NSA12).
The NSC100 can be either fastened to anoptical table or used as a hand-held device toadjust sensitive optical components via anRS-232 interface.
Measuring just 60 mm in length and 30 mm indiameter, the NSA12 is designed to be a directreplacement for manual micrometers. Accordingto Newport, the NSA12 uses a high-torquestepper motor to provide better than 0.3 µmincremental steps at 1 mm/s, and can carry amaximum load of 18 N.www.newport.com
FramegrabbersLambda PhotometricsIntegral Technologies’ range of FlashBusSpectrim framegrabbers is now available fromUK-based distributor Lambda Photometrics.
Designed for OEM applications, the FlashBusfamily uses a Philips TriMedia video processorand a 16 MB SDRAM frame buffer. It alsofeatures multiple composite, S-video andcomponent video inputs as well asbus-mastering video acquisition and real-timetransfer of video-to-system.
The FlashBus framegrabbers are compatiblewith Integral’s IVL imaging and vision library. www.lambdaphoto.co.uk
Digital cameraMatrix Vision
The mvCAM-4 digitalimage processingcamera from Germanfirm Matrix Vision is nowoffered with anintegrated 800 MHzcomputer processor.
The camera also uses a high-performance imageprocessor which, according to Matrix, allowspre-processing in real time.
A high-speed digital signal processor controlsthe image sensor and allows flexible acquisitionand exposure control. Progressive-scan CCDs ineither black and white or colour, with resolutionsfrom 640 ×480 to 1280 ×1024 pixels, act asimage sensors.
The camera is compatible with Windows2000, Windows 98 and LINUX. Matrix says thatusers can develop their own applications eitherdirectly on the camera or on a standard PC.www.matrixvision.de
PRODUCTS
OLE • Apr i l 2004 • optics.org
Optical design softwareRSoftThe RSoft Design Group of the US has releasedOptSim 4.0, a software package that isintended for applications such as designingand simulating optical communication systems.
The company says that the new OptSim 4.0package brings together previous versions ofLinkSIM and OptSim in a powerful graphicaluser interface, while continuing to maintainbackward compatibility with the previousgeneration of software.
OptSim 4.0 merges block mode, which suitsfast simulations, with sample mode, which suitslonger simulations in which unlimited sequencelengths are used. The software can be used todesign all types of communication systemincluding all-optical networks, metro areanetworks and optical LANs.
The company says that it can also integrateits OptSim software into ModeSYS, whichsimulates multimode optical links.www.rsoftdesign.com
Area scan cameraDalsa
Canada’s Dalsa hasintroduced an areascan camera called thePantera TF 1M60, whichis said to be theindustry’s only 12-bit,1024 ×1024 area scan
camera that can give frame rates of 60 frame/s.It offers a dynamic range of more than 66 dBwithout the need for cooling.
The Pantera TF 1M60 is built around Dalsa’sTrueFrame CCD image sensor technology, whichis said to deliver outstanding resolution andgreyscale characteristics. It has a 12 µmsquare-pixel format, a 180 k electron full welland a 100 per cent fill factor. The firm claimsthat this combination delivers superior,quantifiable image quality at low light levels.
The Pantera TF 1M60 is said to be suitable forhigh-fidelity applications such as automatedX-ray inspection, non-destructive testing andmedical imaging.www.dalsa.com
Matched optical flatsOptical Surfaces
UK-based OpticalSurfaces claims that itcan supply matchedpairs of optical flats upto 150 mm in diameter,with matchingaccuracies of up toλ/300.
The pairs are typicallycoated to maximize throughput in the spectralregion of interest.
These components are available in materialssuch as UV-grade silica and germanium.www.optisurf.com
Solid-state lasersMelles Griot
Melles Griot hasintroduced its85 GCJ-series ofultracompact, diode-pumped, solid-statelasers. These devices
produce up to 20 mW of output at 532 nm. TheUS-based company claims that theseconduction-cooled lasers operate in TEM00
mode with an M2 of less than 1.2 and amaximum peak-to-peak noise of 3 per cent.
The company believes that its new two-partformat gives OEM system developers theflexibility to mount the laser head separatelyfrom the controller. The laser head and powersupply each dissipate just 5 W, according toMelles Griot, so minimal heat-sinking isrequired. The 85 GCJ-series lasers are also saidto exhibit good long-term power stability overambient temperature fluctuations of 30 °C.www.mellesgriot.com
Silicon avalanche photodiodesUDT Sensors
UDT Sensors, asubsidiary of OSISystems, has launcheda new line of siliconavalanche photodiodes
(APDs) that are said to have fast response timesand high sensitivity.
The APDs have active area diameters from300 to 900 µm and a high internalmultiplication. The APDs are also said to besensitive from 400 nm to 1100 nm, with a peaksensitivity at 850 nm. They are available in ahermetically sealed TO-46 package with either aflat window or micro lens cap.
These devices are intended for use ininstruments such as laser rangefinders, bar-code readers, optical remote controls and high-speed photometry applications.www.udt.com
Photonic crystal fibreBlazePhotonicsBlazePhotonics of the UK is selling photoniccrystal fibres that can transmit 440 nm, 570 nmand 800 nm light. The new fibres have beenfabricated using a process that is said to makesmall-scale photonic-crystal fibre structures inthe visible part of the spectrum withunprecedented precision.
The process is also said to offer a lower levelof structural distortion than was previouslypossible, resulting in improved mode qualityand lower attenuation.
The seven-cell core fibre for 800 nm light isdesigned to carry powerful ultra-short pulsesfrom Ti:sapphire lasers. It is expected tosignificantly improve the performance of thebeam delivery systems, particularly forapplications in which it is important to focus thelaser beam onto a small spot. For example, its800 nm hollow-core fibre carries the 150 fs 10 nJpulses of a typical Ti:sapphire laser over severalmetres without significant pulse broadening.
Similar fibres are available for use with lasersoperating at 1060 nm and 1550 nm. Otherwavelengths are available on request.www.blazephotonics.com
Ultrafast laserPhotonic Solutions
Quantronix’s Integrafemtosecond lasersystem now has anupgraded, morecompact cousin — theIntegra-C. The Integra-Cis a convenient source
of high-energy (more than 2.5 mJ) femtosecond(less than 100 fs) pulses.
The system’s UK distributor, PhotonicSolutions, says that its high pulse energy,temperature stability and small size make itideal for applications in ultrafast spectroscopyand dynamic studies, as well as precisionmicromachining in which the heat-affected zonemust be kept to an absolute minimum.
The Integra-C is based on patented, fieldtested regenerative amplifier/multi-pass poweramplifier architecture. Further improvements inthe Integra-C include improved thermalstabilization so that it is able to operate tospecification within a ±5 °C range, making itextremely stable in laboratory conditions.www.psplc.com
45OLE • Apr i l 2004 • optics.org
PRODUCTS
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Red laser systemLaser Innovations
The new Genesis RedQ-switched Nd:YAGlaser system from theUK’s Laser Innovationspromises an averagepower of 12 W at
659 nm and a long-term power variation of1.5%. This system, which is described ascompact and long-life, uses a combination ofQ-switching, second harmonic generation andprecise temperature control.
The diameter of the exit beam is said to varyfrom 2 to 3 mm through to the full power rangeand the beam divergence is 4 mrad, althoughthe optional beam expander is said to reducethis to less than 1 mrad full angle.
Pulse repetition frequency can be variedbetween 10 and 25 kHz. The system can bepowered from a standard 220 V power socket,draws only 6 A of current and does not requireexternal water cooling.www.laser-innovations.co.uk
Radiometric headBFi OPTiLAS
BFi OPTiLAS is nowselling Ophir Optronics’photodiode-baseddetector head, whichhas a flat spectralresponse from 400 to
1000 nm. The PD300-BB is said to be ideallysuited to measuring the output power ofbroadband light sources.
According to BFi, the detector can measurebetween 50 pW and 8 mW of power. The thin,low-profile head has a 10 ×10 m aperture with aresponse time of 0.2 s and a low noise level of±2 pW. The detector is said to be fullycompatible with Ophir’s Orion, Nova andLaserstar displays.www.bfioptilas.com
TEM cameraSoft Imaging SystemGermany’s Soft Imaging System has optimized itsCantega2k camera to improve its performance,user-friendliness and range of functions.
Cantega2k is a high-resolution TEM camerawith a resolution of 2048 ×2048 pixels. Theoptimized camera is said to offer three differentread-out rates. In the 5 MHz and 3 MHz modes,the camera acquires up to 5 frame/s at a bitdepth of 14 bits. The 1 MHz mode acquiresimages at a true bit depth of 16 bits. Higherframe rates are also said to be possible with theintegrated partial read-out mode.
The Cantega2k camera’s scintillator and CCDchip are fibre-optically coupled and this,combined with cooling of the CCD chip down to–40 °C, is said to ensure high sensitivity and
signal yield, and a good signal-to-noise ratio. www.soft-imaging.net
High-power laser diodePro-Lite TechnologyAxcel Photonics’ LambdaLokT series ofgrating-stabilized laser diodes is now availablefrom Pro-Lite Technology, the UK-baseddistributor. The high-power lasers feature avolume Bragg grating (VBG) to ensure a narrowlinewidth, and give a temperature-relatedwavelength stability that is allegedly 30 timesbetter than raw diodes.
The VBG “locks” the wavelength and narrowsthe spectral linewidth to typically 0.3 nm with atemperature coefficient of 0.01 nm per 1 °C.Pro-Lite says that the diodes are ideal pumpsources for solid-state lasers and Ramanspectroscopy and are currently available atoperating wavelengths of 785, 808 and 976 nm.
Both singlemode emitters with a 3 µmaperture and broad-area multimode emitterswith a 50–460 µm aperture are available. Thesinglemode emitters achieve output powers of150–500 mW depending on wavelength, whilethe multimode series emit 20–40 mW permicron stripe width. Recent data shows that a100 µm 965 nm emitter can generate 15 W ofoptical output power. www.pro-lite.uk.com
Measurement headILX LightwaveILX Lightwave, the US maker of photonicinstrumentation and test systems, hasreleased a sensor head for measuring theoutput power and wavelength of 350–530 nmlaser diodes. The OMH-6732B head measurespower up to 1 W and is calibrated to NISTtraceable standards.
ILX says that when equipped with the newhead its OMM-6810B optical multimeter orLPA-9080 Series parameter analyser becomethe only instruments that are able to makeintegrated power and wavelengthmeasurements in this spectral region. www.ilxlightwave.com
Chillers Lytron
Lytron of the US is nowoffering a version of itsKodiak recirculatingchiller that iscompatible with thecoolant Polyalphaolefin(PAO). The use of PAOas a cooling medium is
popular for aerospace and military applicationsdue to its dielectric properties and wideoperating temperature range. PAO compatibilityis available on Kodiak chillers with coolingcapacities from 1650 to 5300 W.
PRODUCTS
46 OLE • Apr i l 2004 • optics.org
As with all Lytron’s Kodiaks, the PAOcompatible chillers offer many standard featuresin a quiet, small package. The Kodiak featuresexcellent temperature stability and control(typically ±0.1 °C) and immediate response toset-point change. The interface is user-friendly,and maintenance is simple. www.lytron.com
Polarization controllerPhoenix Photonics
Phoenix Photonics, theUK manufacturer offibre-optic componentsand modules, hasintroduced amechanical polarization
controller. The all-fibre device is easy to use andenables an input signal to be converted to anypolarization state. The design utilizes three fibrewaveplates which are rotated to modify the stateof polarization.
The unit is designed to accept bare fibre or900 µm coated fibre. www.phoenixphotonics.com
Cyan laser Jobin Yvon IBH
Jobin Yvon IBH Ltd hasadded a furtherwavelength to itsaward-winning range ofpicosecond pulsedlaser diode sources.The NanoLED-14 emits
pulses with a duration of less than 100 ps at anominal wavelength of 475 nm.
Due to its small size and simple turn-keyoperation, the NanoLED-14 is an attractivealternative to blue argon-ion lasers for manyapplications. Jobin Yvon says that its NanoLEDsare ideal excitation sources for use influorescence lifetime measurements, and addsthat this new cyan diode is particularly wellmatched to important fluorophores such asfluorescein and NBD.
The NanoLED-14 features adjustablecollimation optics with pinhole apertures forbeam circularization, and a gold-platedenclosure to ensure minimal emission of radiofrequency noise. The bench-top driver modulefeatures controls for repetition-rate andsynchronization delay, as well as comprehensivesynchronization options. www.jobinyvon.co.uk
High-power diode lasersMonocromMonocrom of Spain says that it has developed aseries of high-power pulsed diode lasers thatuse an innovative solder-free mountingtechnology. In the design, the diode is clampedbetween two copper blocks, which serve as both
electrodes and a heatsink. Monocrom saysthat the advantages ofthe approach includelower thermal andmechanical stress ofthe laser chip and thelack of the so-called“smile effect”. The
result is higher peak powers in the quasi-CWmode (up to 120 W in 20 ms per bar) and betterfocusing compared to soldered bars. Forapplications that require high energies in the10 ms range (such as aesthetics) the newtechnique permits the design of much morecompact laser heads.www.monocrom.com
InterferometerP-OEThe new INTERFIRE-II interferometer fromPrecision-Optical Engineering (P-OE), UK, isdesigned for quality monitoring tests of opticalcomponents and systems in the infrared regionof the spectrum. It is available with a choice oflasers operating at either 10.6 µm, tunable overthe 9.2 to 10.7 µm waveband, or in the 3–5 µmwaveband range.
A key feature of the INTERFIRE-II is the use ofa focal plane array camera. P-OE says that thisis much more sensitive than previous camerasand offers significantly reduced noise, allowinghigh-quality images of fringes to be acquired.When used with phase shifting fringe analysissoftware, the acquisition of fringes is far morereliable. The greatest enhancement is seen inthe 3–5 µm band, where the lasers aregenerally of low power.www.p-oe.co.uk
SpectrometerHeadwall Photonics The Summit 6400 series of single-beamspectrometer modules from HeadwallPhotonics, US, uses holographic diffractiongrating technology to achieve low stray lightand a wide dynamic range. Designed fororiginal equipment manufacturers, themodules are suitable for integration intospectroscopy-based instruments for industrialprocess monitoring, medical diagnostics,high-throughput screening and laboratoryresearch. Applications include colorimetry,moisture determination, layer thickness,chemical concentration and many others.
All Summit 6400 products utilize a512-element silicon photodiode array detectorand low-noise, 16-bit electronics. Resolutionvaries from 1 to 4 nm, depending on thespectral range chosen. The scan rate is fourspectra per second, while the aperture is f/2.5and the focal length is around 100 mm.www.headwallphotonics.com
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OLE • Apr i l 2004 • optics.org
RECRUITMENTTo advertise your job vacancies, contact Rob Fisher (tel: +44 (0)117 930 1260; e-mail: [email protected]).
49OLE • Apr i l 2004 • optics.org
US
Shoquist appointmenttakes JDS to next levelJDS Uniphase of San Jose, California, US, hasappointed Debora Shoquist as its new seniorvice-president of operations. Shoquist will beresponsible for more than 2400 employeesand 200 product lines throughout NorthAmerica, Asia and Europe.
According to Kevin Kennedy, CEO of JDSU,Shoquist’s appointment will help thecompany to raise the effectiveness of itsoperations to a higher level. He said:“Debora’s proven abilities to integrate andconsolidate operations, reduce costs andefficiently manage the supply chain areprecisely what we need.”
Prior to joining JDSU Shoquist ran eightmanufacturing sites worldwide for Coherent.
US
3D display maker addsengineering expertiseYigal Banker has joined 3D display makerActuality Systems of Boston, US, as
vice-president of engineering. He will beresponsible for developing the company’s keytechnology, the Perspecta Spatial 3D System,as well as all future products.
Banker is a well known engineeringexecutive and entrepreneur with more than25 years of senior-level experience in thehigh-tech field. Cameron Lewis, presidentand CEO of Actuality, said: “His knowledgeand expertise will be instrumental as wecontinue to expand our products.”
The Perspecta system is a 20 inch domethat plugs into a PC to display full-colour 3Dimages that can be viewed and manipulatedfrom any vantage point. It has applications infields such as defence, medicine and security.
IRELAND
Irish photonics venturetargets North AmericaDublin-based laser diode maker EblanaPhotonics has selected Daniel Tine as its newhead of North American sales and businessdevelopment. Eblana supplies laser productsto the high-volume broadband accesscommunications market.
An industry veteran, Tine is backed up bymore than 10 years of marketing andbusiness experience in the opticalcomponents sector. He commented: “I amdelighted to join Eblana’s world-class teamand take up responsibility for growingEblana’s business in North America.”
US
Diomed to strengthen its board of directorsMedical laser maker Diomed has addedJoseph Harris to its board of directors. He willalso serve on the company’s audit committee.Harris is currently a partner in TrilliumLakefront Partners III, a venture capital firm,and his background includes stints atSmithKline Beecham and Eastman Kodak.
Geoffrey Jenkins, chairman of the Diomedboard, said of Harris: “His expertise inbusiness development and his financialacumen will serve as a strong complement tothe talents of our other board members.”
Based in Andover, Massachusetts, Diomedis the company behind products such as theEVLT laser varicose vein treatment system.
Polymicro Technologies, LLC
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Avantes www.avantes.com 49 BFI Optilas Internationalwww.bfioptilas.avnet.com 6, 19, 20
Blaze Photonics www.blazephotonics.com 28Breault Research Organizationwww.breault.com IFC
Cristal Laser www.cristal-laser.fr 43Crystran Ltd www.crystran.co.uk 36CVI Technical Optics www.cvilaser.com 28 Edmund Industrial Opticswww.edmundoptics.com 20
ELCAN Optical Technologieswww.elcan.com 12, 24
FOCtek Photonics www.foctek.com 38Fujian Castech Crystals Incwww.castech.com 40
GSI Lumonics www.gsilumonics.com 10GWU Lasertechnik www.gwu-group.de 39Hamamatsu Photonics UKLtd www.hamamatsu.co.uk 9Hinds Instruments www.exicor.com 42Kentek Corp www.kentek.com 25
Labsphere www.labsphere.com 4 Lambda Research Optics Incwww.lambda.cc 18
Laser Componentswww.lasercomponents.com 44
Lasermet Ltd www.lasermet.com 31LIMO Laser Systems www.limo.de 9Melles Griot www.mellesgriot.com OBCMicro-Controle www.newport.com 31New Focus Europe www.newfocus.com 32Ocean Optics www.oceanoptics.com 25, 45O.M.P. 2004 www.omp-online.com 23 Ophir Optronics Ltd www.ophiropt.com IBCOptatec 2004 www.optatec-messe.de 36Optikos Corp www.optikos.com 20Pacer Components Plcwww.pacer.co.uk 20, 23
PCO AG www.pco.de 41Photon Inc www.photon-inc.com 47Photonic Productswww.photonic-products.com 41
Photonic Solutions plc
www.psplc.com 20, 30, 48Physik Instrumente GmbH www.pi.ws/oleb 14Piezosystem Jena www.piezojena.com 42Polymicro Technologies www.polymicro.com49Powerlase Limited www.powerlase.com 31Precision Optical Engineeringwww.p-oe.co.uk 36
Scitec Instruments Ltd www.scitec.uk.com 23Southampton Photonicswww.spioptics.com 22
Stanford Computer Optics GmbHwww.stanfordcomputeroptics.com 38
Stanford Research Systems Incwww.thinkSRS.com 33
StellarNet Inc www.stellarnet.us 44StockerYale Canada www.stockeryale.com 28Synrad Inc www.synrad.com 16Toptica AG www.toptica.com 20Umicore Coating Serviceswww.coatingservices.umicore.com 46
Unaxis www.unaxis.com 42Vision 2004 www.vision-messe.de 37
50 OLE • Apr i l 2004 • optics.org
April 18–21 Optical Data Storage Monterey, US SPIE, US spie.org/conferences/calls/04/ods
April 19–21 PICALO Melbourne, Australia LIA, US www.laserinstitute.org/conferences/picalo
April 21–23 Optics in Computing Engelberg, European Optical www.oic2004.comSwitzerland Society, Germany
April 25–30 High-power Laser Ablation Taos, US SPIE, US spie.org/Conferences/Programs/04/hp
April 26–30 Photonics Europe Strasbourg, France SPIE, US spie.org/Conferences/Programs/04/epe
April 27–29 Opto China 2004 Shanghai, China Reed Exhibitions, UK www.optochina.com.cn/english/index.htm
April 27–30 ILOPE 2004 Beijing, China COEMA, China ilope.ciec-exhibition.com.cn
April 29–30 The Fundamentals of OLED San Francisco, US Intertech, US www.intertechusa.comFabrication
May 10–14 Advanced Optical Design Using Stansted, UK Optima Research, UK www.optima-research.com/Training/ZEMAX ADVODUZ.htm
May 17-20 Photonic Applications Systems San Francisco, US OSA, US www.phastconference.orgTechnology Conference (PhAST)
May 16–21 CLEO/IQEC 2004 San Francisco, US OSA, US www.cleoconference.org
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