the european magazine for photonics professionals optics · cover (zygo) a head-mounted display...
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The European magazine for photonics professionals optics.org
CMOS SIMUL ATION
Modelling speeds CMOS simulation by a factor of twenty
MACROMACHINING
Rofi n reports record sales and growth in macromachining
MARKE T RE PORT
Projection market forces laser makers to adopt new designs
March 2008 Issue 159
MANUFACTURING
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EDITORIALEditor Jacqueline HewettTel +44 (0)117 930 [email protected]
Reporter Marie FreebodyTel +44 (0)117 930 [email protected]
Reporter Tim HayesTel +44 (0)117 930 [email protected]
Senior production editor Alison GardinerTechnical illustrator Alison Tovey
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© 2008 IOP Publishing Ltd. The contents of OLE do not represent the views or policies of the Institute of Physics, its council or its offi cers unless so identifi ed. Printed by Warners (Midlands) plc, The Maltings, West Street, Bourne, Lincolnshire PE10 9PH, UK.
For the latest news about optics and photonics, don’t forget to visit optics.org.
Rewritable 3D hologram displays for hours p10
Slab laser design features fl exible beam profi les p23
Silvia Carrasco discusses ICFO’s expansion p38
Liquid lens makers seek market penetration p6
I s sue 159 March 2008 Contents
Cover (Zygo) A head-mounted display going through Zygo’s DFMA process p20
NEWS5 Business Rofi n sees record sales• Varioptic and Seiko team up on liquid lenses• People
8 Editorial Projection projections
TECHNOLOGY9 Applications Euro project maps nanophotonics• Hologram rewrites rapidly
12 R&D Hybrid lenses prove cost-effective• Harmonics make high- quality images
FEATURE S15 Price and performance key to laser projectors Low-cost lasers are being developed for the display market at previously unheard of price/performance ratios. Matthew Brennesholtz of Insight Media looks at the device specifi cations for various projection applications and the key players in the market.
17 Faster modelling speeds CMOS simulations Computer models of what happens when light hits the pixels of a CMOS image sensor are so complex that each simulation can take days to run. Tim Hayes hears how recent advances in software and hardware can speed up the process by a factor of 20 or even more.
19 Optical trapping moves towards microfl uidics Kishan Dholakia speaks to Marie Freebody about the recent break- throughs in optical trapping and his expectations for the future.
20 Hidden value in high-precision manufacturing There are several common misconceptions surrounding high- precision manufacturing. Jacqueline Hewett speaks to John Stack and David Erickson of Zygo to get a clear picture of what is involved and the benefi ts of adopting this approach.
23 Flexible slab laser gives industry an alternative A laser that produces high-quality light in a variety of beam shapes could be adapted to suit a range of applications. Marie Freebody speaks to Keming Du of EdgeWave to fi nd out more.
25 Iterative steps ensure successful LED lighting White LED technology is evolving rapidly. Pat Goodman and Christos Sarakinos discuss the iterative process that all developers should follow when designing a lighting system.
38 Back chat: Silvia Carrasco on Spanish optics The Institute of Photonic Sciences in Barcelona is undergoing a signifi cant expansion. Silvia Carrasco tells OLE what ICFO can offer and gives a snapshot of Spain’s thriving photonics industry.
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5OLE • March 20 08 • o p t i c s .o r g /o l e
NEWS
As OLE went to press, Toshiba announced that it will stop the manufacture, development and marketing of HD DVD players and recorders. “We assessed the long-term impact of continuing the so-called ‘next-generation format war’ and concluded that a swift decision will best help the market develop,” said Atsutoshi Nishida, the corporation’s presi-dent and chief executive offi cer.
Although Japanese company
Toshiba has discontinued its HD DVD business, the growth of the market for blue laser diodes will escape major disruption from converting exclusively to Sony’s Blu-ray format. So says market analyst Asif Anwar of Strategy Analytics, who thinks that the factors underlying increased sales of the next-generation players will remain otherwise unchanged.
“Our forecasts are pretty bull-ish on the overall growth for laser diode markets, regardless of which format won,” Anwar said.
Impressive growth for GaN laser
diodes is still predicted. Anwar previously forecast that the GaN laser diode market, worth $34 m(722.9 m) in sales in 2006, will grow to $1.2 bn by 2011.
Despite Nishida’s attempts to “help the market”, Anwar does not believe that the cessation of hostilities will be a particu-lar boost to overall sales levels. “The consumer still has to decide when and if they want to buy a next-generation player and I think that is still going to follow the same kind of trajectory that we originally forecast.”
Revenue at Rofi n-Sinar Technol-ogies rose to $135 m (791 m) in the fi rst quarter of fi scal 2008, a rise of 21% over the same quar-ter last year. “It was an outstand-ing quarter and a new record in sales,” commented chief execu-tive offi cer Gunther Braun. “The weaker US dollar helped us, but even subtracting that effect we still showed an impressive 10% increase based on last year’s exchange rates. I believe that we are gaining market share com-pared with our US competitors.”
Sales were particularly strong for the firm’s macromachining products, comprising high-pow-ered laser sources and systems with output powers of up to 8 kW. The quarter included a substantial order from a leading European automotive supplier, which would not be repeated in subsequent results but the mar-ket remains strong, said Braun.
“High demand for CO2 lasers in automotive and machine tool applications led to a 38% increase in sales for these products,” he said. “Demand in Europe and Asia remains high, especially in China, which is now the largest market for our macro machining lasers. We have no reason to believe the market will change.”
Sma l ler i ncreases were
recorded for Rofi n’s other product groups, including a 10% increase in sales of micromachining sys-tems. Results from the compo-nent supply business for diodes, power supplies and fibre-laser products from the newly acquired Nufern were up “slightly, mainly due to the timing of orders and deliveries”, said Braun.
Economic conditions in North America led to a 10% decrease in sales in the region, while sales in Europe and Asia rose by 32%. “Sales to Asia rose by 55%, includ-ing a substantial 12.5% increase
in China,” Braun observed.Higher productivity in high-
power CO2 laser systems manu-facture was also important, and the trend towards higher output powers helped to support prices.
Acquisitions are the other factor in Rofin’s growth plans. “Nufern’s acquisition, completed in January, has added core fi bre and fibre-laser technology to our portfolio,” said Braun. “But our strategy for fibre lasers is unchanged, and we expect to introduce a 1 kW fi bre laser using Nufern fi bres during 2008.”
FINANCIAL RE SULT S
Rofi n sees record sales AC Q U I S I T I O N S
The laser plastic welding and
selective laser soldering segments
of Fisba Optik have been acquired
by Trumpf. The acquisition is said
to allow Trumpf to make a wider
range of laser system applications
available to its customers, and
the company plans to offer its
own laser systems for laser plastic
welding and laser soldering.
Special Optics, a manufacturer
of optical assemblies for long-
range surveillance and laser
applications, has been acquired
by Navitar. Special Optics’ rapid
prototyping and lens design
capabilities will complement
Navitar’s volume production
capacity, say the companies.
LI C E N S I N G
A licence for the manufacture
and marketing of white LEDs
with conversion technology has
been granted to PerkinElmer by
Osram. This technology enables
white LEDs to be produced using
blue-emitting chips based on
indium-gallium-nitrite and suitable
phosphor converters.
PA R T N E R S H I P S
Powerlase has announced
a research partnership with
the National Centre for Laser
Applications at the National
University of Ireland, Galway to
develop novel techniques for laser
materials processing.
SCHOTT Solar and ersol
Thin Film have entered into
a co-operative agreement to
jointly develop micromorphous
technology for thin-fi lm solar cells.
Micromorphous thin-fi lm modules
have a double-layer structure
consisting of an amorphous and a
microcrystalline silicon fi lm.
For all the latest business
news, visit http://optics.
org/cws/channel/industry.
BUSINE S S 5 E DITORIAL 8
Ro
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Sales were strong for Rofi n’s macromachining products and the fi rm experienced high demand for CO2 lasers in automotive and machine tool applications.
NE X T- GE NE R ATION DVD
Blue laser diodes emerge unscathed
IN BRIEF FROM OPTIC S.ORG
BUSINESS
NEWS
An agreement between Seiko Instruments (SII) and Varioptic will see the companies cooperate on the development, manufac-ture and marketing of Varioptic’s liquid lens products, and is intended to lead to significant market penetration.
“Our objective is to become the leading supplier of high- quality image solutions for mobile devices,” said Christian Dupont of Varioptic. “SII’s expertise in the production of low-cost miniature mechanical assemblies makes it an ideal partner.”
The agreement significantly enhances the existing production capacity for Varioptic’s Arctic 314 and Arctic 416 liquid lenses, designed for 5 Mp, 1/3 inch and 1/4 inch format camera modules. SII intends to use its large manu-
facturing capacity to produce liquid lens units in very high vol-umes and apply aggressive cost reductions, building on its exist-ing position as a major supplier of backup batteries and capacitors for mobile phones. The company’s production capacity is expected to
reach 0.5 million units per month by the third quarter of 2008, with further expansion according to market needs.
Liquid lenses use two isoden-sity liquids – one an insulator and one a conductor – on a substrate. Voltage applied to the substrate
leads to a change of curvature of the liquid–liquid interface, which in turn leads to a change of the focal length of the lens. The result is claimed to be a lens unit with a large inverse focal length range and fast response, without moving parts.
In addition to signifi cant pen-etration of the camera module market, the companies intend to target other large volume equip-ment sectors, such as barcode scanners and webcams. The advantages of cost, size and power consumption claimed for liquid lenses are said to position them particularly well for the emer-ging camcorder phone market. Varioptic has stated that devel-opment of the liquid lens technol-ogy will continue to ensure that it remains competitive.
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Varioptic and Seiko Instruments are targeting a production capacity of 0.5 million units per month by the third quarter of 2008, with further expansion to meet market demand as required, especially in the camcorder phone market.
IPG Photonics has made its fi bre-coupled laser diodes avail-able on a merchant basis to OEM cus tomers, in a move said by the company to be a natural expansion of its product line. The decision follows IPG’s recent expansion of production capa-city, with three new multi-wafer molecular beam epitaxy reactors coming on stream last year.
“This is the ideal time to intro-duce the advantages of IPG’s cost-effective diode lasers into the market,” said Valentin Gapontsev, IPG’s chief executive offi cer.
The f ibre-coupled diodes, which are the crucial elements of IPG’s fi bre lasers, deliver power levels of up to 20 W at a range of 9xx nm wavelengths.
“Keep in mind that what IPG really does is fabricate and assemble diodes,” Tom Hausken of market analyst Strategies Unlimited told OLE. “I don’t want to downplay its skill at fabrica ting and assembling the fi bre, but the diodes are essential.”
Hausken described the move as somewhat surprising for IPG, but not unusual for the industry. “Coherent, Newport/Spectra-Physics and JDSU are all well-known for their mer-
chant diodes, as well as the diode-pumped solid-state lasers that use them,” commented Hausken. “What’s unusual is that IPG is the largest supplier of this type of diode in the world, so it is not just another supplier.”
The move could potentially make a sizeable addition to the company’s cash fl ow, while the manufacture of the extra diodes should not add substantially to IPG’s fi xed costs.
“From that perspective it’s a no-brainer,” said Hausken. “The risk is that an expansion like this to a lower layer in the supply chain could distract them from their core business of fabricating
and assembling diodes.”IPG is already the largest
manu facturer and consumer of this type of diode so the move will not affect the overall size of the market, but the company’s volume advantages mean that the merchant business has just become more competitive.
“There are other high-power diode businesses that IPG’s prod-uct doesn’t address, so the move doesn’t necessarily mean the end for anybody,” commented Hausken. “It will change the opportunities for the other mer-chant suppliers though. It adds another competitor and a very challenging one at that.”
L ASE R DIODE S
IPG enters laser diode business
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7OLE • March 20 08 • o p t i c s .o r g /o l e
NEWS
BUSINESS
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PEOPLE
OP TIC SPeter Allard has joined Alpine
Research Optics, the premium
optics brand of Saint-Gobain
Crystals, as Western Area sales
manager. He will be responsible
for sales and marketing of the
company’s high-damage threshold
laser optics for UV, visible and near-
IR applications, serving customers
in the western US.
COMPONE NT SScott Soden has joined Gooch
& Housego as western regional
account manager and Martin Cheng is appointed director of
sales for Asia-Pacifi c based in Hong
Kong. These appointments follow
the employment of Paul Morris
as global senior vice-president of
sales, and are said to be part of the
company’s new global sales and
operations strategy.
L ASE RSBob Bowman has been named
customer service manager by
JPSA, responsible for fi eld service
and customer satisfaction. The
appointment refl ects the company’s
expansion and growing customer
base, according to a statement.
L ASE RSStephan Geiger has been
appointed managing director
of Rofi n/Baasel Lasertech in
Starnberg, Germany. He started his
career at Rofi n and also worked for
the company’s Bavarian Photonics
subsidiary. Rofi n has also named
Christine Hermann as division
manager of the R&D department.
PL ANAR LE D SPeter van Strijp has joined the board
of Oree Advanced Illuminations
Systems, a developer of planar LED
illumination. Van Strijp is a former
vice-president of Philips Lighting and
chief executive offi cer of its solid-
state lighting business.
CAME R ASMike Decelle has been appointed
president and chief executive
offi cer of NoblePeak Vision, a US
start-up developing visible and
infrared surveillance camera cores
and components. He replaces co-
founder Cliff King, who becomes
chief operarting offi cer to focus
on new product development and
manufacturing. NoblePeak plans to
introduce its TriWave camera cores
this year.
SYS TE M DE SIGNOrb Optronix, a provider of opto-
electronic system design and
integration, has appointed Daniel Hill as senior optical engineer in its
optical engineering services group.
Hill has a background in imaging
and non-imaging optics, and is also
a former course instructor in Zemax
optical design software.
IMAGINGMichael Fowler has been named
interim CFO by eMagin.
L ASE RSJMAR Technologies has elected
James McCarthy to its board of
directors. McCarthy is chairman of
a consulting company focused on
the healthcare industry.
PHOTONIC SRobert Friel has been elected chief
executive offi cer of PerkinElmer and
will also retain the title of company
president. This is consistent with the
company’s leadership succession
plan announced in July 2007.
8 OLE • March 20 08 • o p t i c s .o r g /o l e
NEWS
EDITORIAL
Welcome to the March issue of OLE.As I write this, one month has passed since Photonics West, which means that OLE’s editorial team has had a chance to digest and follow up on some of the new technologies and applications that were on show in San Jose. The result is an issue packed with news and features discussing topics ranging from the market for lasers in projection applications and high-precision manufacturing to slab lasers and white LEDs.
In this issue, Matthew Brennesholtz of Insight Media looks at the device specifi cations for applications such as handheld pico-projectors and laser television. He also discusses the radically different price/performance ratios that laser developers must meet in order to enter the display market. Here’s a quote that puts things into perspective: “Display makers typically want a minimum of 100 000 sets of lasers. If you ask a traditional laser manufacturer to quote for 100 000 532 nm 3 W green lasers, you are likely to get a blank stare.”
There is no doubt that this market is gaining momentum. Recent developments include Arasor’s acquisition of Novalux and Mitsubishi introducing a rear-projection TV that uses red, green and blue lasers for illumination. This is the fi rst formally announced mass-market projector containing lasers, although Mitsubishi gave neither a specifi c availability date nor a retail price for the system.
While LEDs have stolen the march on lasers when it comes to projection applications, change is certainly in the air. “Insight Media expects lasers will arrive on the market, probably sooner rather than later,” Brennesholtz predicted. With several key laser names in the market and no doubt several more that have still to play their hand, it will be interesting to see just how long we have to wait. Brennesholtz’s article is an intriguing read and I would encourage you to turn to p15 for more details.
On a similar theme, Pat Goodman from Philips Lumileds and Christos Sarakinos from Future Lighting Solutions have put together an invaluable guide to high-power white LEDs and the steps that any developer should go through when designing a lighting system. Please turn to p25.
Jacqueline HewettE-mail [email protected]
“LEDs have stolen the march on lasers when it comes to projection but change is in the air.”Jacqueline Hewett
Projection projections
9OLE • March 20 08 • o p t i c s .o r g /o l e
TECHNOLOGY
A project involving Europe’s leading photonics companies and institutions has produced a roadmap that will shape future research funding in nanophoton-ics. With contributions from more than 300 experts in the fi eld, the 161-page document is designed to serve as an informed input for future research funding by the European Commission under its 7th Framework Programme.
The “European Roadmap for Photonics and Nanotechnol-ogies” is the culmination of a two-year effort coordinated by the MONA (Merging Optics and Nanotechnologies) project. The document analyses seven key markets for photonics products – ranging from fl at-panel displays through to imaging and opti-cal interconnects – to work out which nanophotonics technolo-gies will have greatest impact on future market growth.
Quantum dot structures fea-ture particularly strongly, and are expected to have a major impact
in almost all of the pho tonics markets studied in the roadmap. One key recommendation is that quantum dots based on III-V materials should be developed for photovoltaics applications.
“The photovoltaics market is growing,” said the report. “Quan-tum dot technology offers greater fl exibility in the management of bandgap, current and strain to achieve higher conversion effi -ciencies.” MONA believes that
Europe is well placed to address this opportunity, with strong R&D in the field as well as the presence of leading materials and equipment suppliers.
Imaging, lighting and data storage are three more appli-cations where quantum dots could have an impact, says the roadmap. And quantum dots and wires in silicon will also be important for optical intercon-nects, UV sensors and multi-
junction solar cells.The report also calls for inten-
sifi ed R&D in lighting applica-tions, where technologies such as quantum dots, photonic crystals and nanostructured mater ials are expected to offer effi ciency improvements in both inorganic and organic LEDs. This is seen as an important strategic area for European research, with both Osram and Philips playing on the world stage.
Imaging is another fi eld where Europe can already boast a strong research base and glo-bal market presence. For visible imaging, the roadmap highlights the need for nanostructured lenses, most likely based on plas-monic devices, to produce CMOS image sensors with ever smaller pixel sizes. And infrared ima-ging specialists, such as Sofradir and CEDIP, are hoping to use quantum dot structures in a new generation of detectors that will replace existing quantum-well infrared photodiodes.
NANOPHOTONIC S
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Euro project maps nanophotonics
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Researchers in the US are using terahertz radiation to evaluate underdrawings that have been covered and hidden over time by plaster or additional art work. The process uses a pulsed terahertz refl ectometer and imaging system to detect metallic and dielectric paint patterns through additional layers of paint and plaster(Optics
Communications 281 527).“We can clearly resolve images
that are buried beneath layers of plaster or paint,” John Whitaker, a researcher from the University of Michigan, told OLE. “We can determine the size and shape of drawings made with a variety of different materials and we hope to extend this to eventually dis-tinguish different colours.”
Whitaker and his colleagues are collaborating with research-
ers from the world-famous Lou-vre Museum in Paris and US fi rm Picometrix. The group is using the T-Ray system developed by Picometrix, which can penetrate up to 1 cm of plaster.
The team’s set-up uses a Ti:sapphire laser emitting at 810 nm and a repetition rate of 80 MHz. Pulses with a duration of 100 fs are fi red onto a photo-conductive switch, which con-verts them into terahertz pulses
with a duration of around 1 ps. As the object is scanned, the
amount of reflection changes depending on the material that the pulses are hitting. “From each point we get a time-domain series of pulses with information about the refl ection from each discrete layer,” explained Whitaker. “The characteristics of the measured pulses are then correlated with the position that they hit the mural, and an image is created.”
TE R AHE RTZ
Terahertz pulses image hidden art
The MONA report recommends intensifi ed research and development in lighting applications based on technologies such as quantum dots and photonic crystals.
OS
RA
M
10 OLE • March 20 08 • o p t i c s .o r g /o l e
TECHNOLOGY
APPLICATIONS
US researchers believe that they have created the first 3D holo-graphic display where the image can be erased and updated within a matter of minutes. The device, which measures 4 ×4 inches and can be viewed without special eyewear, uses a light-sensitive polymer that can also store 3D images for several hours (Nature451 694).
“Our holographic displays are the fi rst updateable, three-dimensional displays with mem-ory ever to be developed,” Nasser Peyghambarian, a researcher from the University of Arizona, told OLE. “They are ideal tools for applications that require situational awareness, such as medical, industrial and military imaging, and for advertisement and entertainment.”
Although holographic 3D displays are now commercially available, uptake has been limited because they do not offer the abil-ity to refresh the image. “Existing 3D holographic displays cost tens of thousands of dollars, and since they are permanent, the cost per image is very high,” explained Peyghambarian. “Our displays can be refreshed with new images every few minutes so you can have an unlimited number of 3D images using one display.”
The key to the new device is a light-sensitive plastic fi lm made from a photorefractive polymer. While the photopolymers used in existing holographic displays exploit chemical reactions that cannot be reversed, photore-
fractive materials are based on the movement and trapping of charges generated within the material by light – a process that is fully reversible.
“Images are written onto the polymer using two incident coherent laser beams and an externally applied electric fi eld,” explained Peyghambarian. “The interference pattern from the two laser beams creates bright and dark regions across the material. Charges are generated in the bright region as a result of absorption of light. Positive charges move to the dark regions and negative charges move to the bright regions.”
The result is a space-charge field within the polymer that replicates the interference pat-tern created by the laser beams. This space-charge effect modi-fies the local refractive index,
which enables the hologram to be encoded as a refractive index pattern. A 633 nm laser can then be used to diffract from this index hologram and create the 3D image.
The ideal photorefractive poly-mer for this application should offer both rapid recording times and a low decay time, but most polymers with fast recording times also lose the image very quickly. The Arizona team over-came this problem by developing a composite based on a co-poly-mer, which it says minimizes the phase separation between func-tional elements that compromise the performance of the photo-refractive polymers.
The space-charge fi eld can be erased within minutes by using a spatially uniform 532 nm laser beam to re-distribute the charges uniformly inside the polymer.
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German researchers have used an ultrashort pulsed laser to cre-ate subsurface nanostructures in a sapphire crystal. The tech-nique could be used to fabricate microfl uidic devices as well as 3D photonic structures (Optics Express 16 1517).
Rather than using the laser for direct machining of the sap-phire surface, the team exploited the fact that irradiation with ultrashort laser pulses generates a highly nonlinear light-matter interaction beneath the surface of the material. Subsequent etch-ing with hydrofl uoric acid pro-duces self-assembled nanoplanes within the material, perpendicu-lar to the beam’s polarization.
“The irradiation induces some physical effects in the material that lead to the formation of these structures, but there is no beam shaping or special process-ing technique involved,” Dirk Wortmann of RWTH Aachen University told OLE. “Hence we describe the structures as being self-assembled.”
There are several theories for what lies behind the self-assembly effect in sapphire, ranging from an interference effect between laser-induced plas-mon waves, to a “density wave” in the partially molten material that becomes rapidly frozen in place.
Another result of the laser pulse is to drastically accelerate the speed of the etching. Irradi-ated areas were etched up to 10 000 times faster than the unaltered areas.
Pulses etch into sapphire crystals
MICROFLUIDIC S
Top row: erasure of a 3D image of a human skull. Middle and bottom rows: 3D images shown from different angles, demonstrating horizontal parallax.
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Optec-Berlin-Brandenburg (OpTecBB) e.V. - the competence network for optical technologies for the region Berlin and Brandenburg, Germany.
OpTecBB is part of the strategy process to develop and strengthen optical technologies in Germany. OpTecBB e. V. was established on 14/09/2000 by companies, research institutes and universities as a non-
A partner of Laser Optics Berlin and a member of OptecNet Deutschland, OpTec BB represents both the optical competence networks of Germany and some of the leading Photonics companies in the world.
Optec-Berlin-Brandenburg (OpTecBB) e.V.Rudower Chaussee 25, 12489 Berlin, GermanyTel: +49 (0)30 / 6392-1720Fax: +49 (0)30 / 6392-1729Internet: http://www.optecbb.de E-mail: [email protected]
Chairman of the board: Günther TränkleExecutive director: Bernd Weidner
Activities of OpTecBB are supported by
Optec-Berlin-Brandenburg (OpTecBB) e.V.
See us atLaser Optics
BerlinHall 18/310
OLEMar08p11.indd 1 26/2/08 14:55:41
12 OLE • March 20 08 • o p t i c s .o r g /o l e
R&D
TECHNOLOGY
A range of hybrid optical com-ponents that combine both a glass and a polymer element is now available from Edmund Optics. The hybrid aspherized achromats are said to bridge the gap between colour-corrected ach romat s a nd spher ica l aberration-corrected aspheres and suit applications such as fibre-optic focusing and high numerical aperture imaging.
“We saw a big gap in the mar-ket in terms of performance and cost,” Gregg Fales of Edmund Optics told OLE. “While the cost of machining aspheres does not scale well with volume, the cost of molding aspheres, and of manufacturing doublets, does. These components have bet-ter chromatic correction than typical achromats and nearly the same spherical correction as machined aspheres – all at a very affordable price.”
According to Fales, these components will outperform machined aspheres in polychro-matic applications with an order of magnitude cost savings in vol-ume. At the same time, he believes that they will outperform achro-mats in both monochromatic and polychromatic applications at very little extra cost.
The company creates its glass-polymer hybrid by manufactur-ing both a standard glass doublet
and a mold for the aspheric sur-face. A liquid photopolymer is injected into the mold before the mold and the doublet are pressed together. The fi nal step uses UV light to cure the polymer to the doublet and create the aspher-ized achromat.
Fales says that the polymer layer is typically just 100 mthick and that the fi nal compo-nent is more than 99% glass. He adds that Edmund Optics can provide optical designers with all the information that they need (an Abbe number and six reference index values) to model these lenses.
To date, Edmund Optics has successfully aspherized achro-mats from 9 mm in diameter up to 25 mm but is confident that this can be extended down to 5 mm and up to 50 mm.
“The real advantage of this technology is with aspherizing achromats, but we could cer-tainly apply it to singlets,” com-mented Fales. “The radius can be concave, convex or plano. The process is most advantageous for low f-number lenses (F/4 and below). Longer focal length lenses typically don’t suffer from large amounts of spherical aber-ration so adding an aspheric surface will not upgrade the per-formance signifi cantly.”
Nine hybrid lenses are now available from Edmund Optics with diameters ranging from 9 to 25 mm and focal lengths from 12 to 50 mm. “We are eager to expand the family and of course eager to work with our customers to help integrate these designs, or custom designs, into their appli-cations,” concluded Fales.
ASPHE RIC LE N SE S
Hybrid lenses prove cost-effective
Electronic Design EngineerDescription/ResponsibilitiesYou will define and develop products for the communication and information technology industry and controlinternal and external R&D and manufacturing partners.
Experience/SkillsCandidates should have a university degree specializing in embedded microprocessor circuits andprogramming. Candidates should have a University or FH degree in electronics or related fields preferably withexperience in embedded microprocessor systems. Knowledge of 32-bit embedded microprocessors,wireless&wired interfaces, experience in development and productisation of of embedded system as well asexperience in HW/SW integration are needed, experience in object oriented languages on mobile platformsutilizing wireless technology like UMTS/GPRS and GSM would be preferred. Good English communication skillsare a pre-requisite for this position.
PHOTEON Technologies GmbH, Kirchstrasse 35, 6900 Bregenz – Austria (Europe) [email protected], http://www.photeon.com
Optical Design EngineerDescription/ResponsibilitiesYou will be involved in the design, simulation and development of planar lightwave circuits (PLC) on silica andon polymer basis. With the help of state of the art design tools and additional inhouse tools you will designdevices for fibre to the home and optical communication applications. A detailed understanding of integratedoptics and fibre optical applications is recommended and experiences in the design of integrated optical deviceswould be of advantage.
Experience/SkillsCandidates should have a university degree specializing in integrated optics. Good analytical skills for problemsolving, good technical writing skills, and computer programming skills (C++) would be preferred. ExcellentEnglish communication skills are a pre-requisite for this position.
... making waves with lightTM
NEWS FROM OPTIC S.ORG
Physicists in the UK and Germany
have harnessed the curious
properties of soliton waves to
create a new type of semiconductor
laser that can be switched on and
off using light pulses. The team
believes that this “cavity soliton
laser” could play an important role
in all-optical telecoms systems,
in which data are switched and
routed without the need to convert
light pulses into electrical signals
and back again.
The system, which is based on
a VCSEL built by the German fi rm
ULM Photonics, was assembled
and characterized by Thorsten
Ackemann and colleagues at the
University of Strathclyde in the UK
(Phys. Rev. Lett. 100 013907).
The present device emits at
a wavelength of 980nm but
Ackemann believes that in principle
there are no obstacles to the
realization of similar cavity soliton
lasers that operate at telecoms
wavelengths and describes this as a
“challenge for the future”. The team
is also working on miniaturizing
the device, which currently has
an external cavity that is 50 cm in
length.
To view the full article and fi nd
out how the team’s cavity soliton
laser works, visit http://optics.org/
cws/article/research/32598.
Ed
mu
nd
Op
tic
s
The polymer layer is 100 μm thick and the lenses are more than 99% glass.
R&D
TECHNOLOGY
IMAGING
Harmonics make high-quality imagesA team of US, Swiss and German scientists has found that second harmonic signals generated by a femtosecond laser can be used to produce high-contrast images with a temporal resolution of about 150 fs. The researchers believe that the new imaging technique, which they have called harmonic holography, will enable the dynamics of complex biological processes to be studied in 3D (Appl. Opt. 47 A103).
“To the best of my knowledge, this is the fi rst time that second harmonic signals have been used to record holograms,” Ye Pu of the California Institute of Tech-nology told OLE. “We believe this is a completely new holographic principle that will unleash the 3D capability of holography in microscopy and provide a unique tool for biomedical imaging.”
Although a number of imaging techniques are currently used to probe biological samples, none are able to combine the high-contrast imaging needed to iden-tify individual molecules with the ability to track fast-moving biological processes.
In contrast, holography is well known for its 3D imaging capability and taking a number of images in quick succession enables dynamic processes to be followed in time as well as space. The problem is that conven-
tional holography lacks contrast between what is of interest (the signal) and what is not (the back-ground), which has so far limited its use in biological imaging.
The solution adopted by the team is to produce a holographic image from second harmonic signals that are generated when pulses from a femtosecond laser pass through a special type of nanocrystal. “Second harmonic generation provides a strong con-trast mechanism in the coherent domain,” said Pu. “Because most liquids and biological structures are isotropic, they are incapable of frequency doubling. Second harmonic generating nanocrys-tals can be picked up easily in the double-frequency band with a dark background.”
Only nanocrystals with non-centrosymmetric structures are capable of producing such second harmonic signals. The Caltech group used 100 nm nanocrystals
of barium titanate. In the experiment, 810 nm
femtosecond laser pulses with an energy of 2 mJ were split into a pump and a reference beam. Firing the pump beam at the nanocrystals produces second harmonic signals, which then interfere with the frequency-doubled reference beam to create the holographic image.
According to Pu, the temporal resolution is about 150 fs, limited only by the laser source. The spa-tial resolution is around 1.8 m in the lateral direction and 4 m axi-ally at a numerical aperture of 0.5, although these could be improved by increasing the numerical aper-ture of the system.
“Together with Scott Fraser’s group in the biology division here at Caltech, we are working to push the second harmonic generat-ing nanocrystals into the critical 10 nm regime for real biological applications,” commented Pu.
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Optical Powermeter News
• Stabilized Broadband Sensors for 10 W with μW Resolution
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NEWS FROM OPTIC S.ORG
Researchers in the US have built
an optical clock from strontium
atoms that they claim is the world’s
most accurate clock to use neutral
atoms. According to the team, the
time piece is accurate to about one
part in 1016 and would neither gain
nor lose a second in more than
200 million years. (Science DOI:
10.1126/science.1153341).
The clock, which was built by Jun
Ye and colleagues at JILA and the
University of Colorado in Boulder,
is based on strontium atoms that
are trapped by overlapping infrared
laser beams. The atoms are
bathed in light from a separate red
laser at a frequency corresponding
to an atomic transition in
strontium, which causes this light
to lock into the precise frequency
of the transition. This is the fi rst
neutral-atom timekepeer to be
more accurate than the standard
caesium-fountain atomic clock.
The team determined the clock’s
accuracy by sending its time signal
via a 3.5 km underground optical
fi bre from JILA to NIST (also in
Boulder) where the signal was
compared to that from an optical
clock based on neutral calcium
atoms.
To read the original article, visit
http://optics.org/cws/article/
research/32963.
Ye P
u
variable delay
M4
M5
BS1
M6M1
M2
F1
F2
L1
L2
M3
BBOM7
BS2F3 F4S
L3
ASP OBJ
2ω
2ω
1 mJ 150 fs
ω
CCD
The team is now trying to implement its ideas in a practical imaging instrument.
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15OLE • March 20 08 • o p t i c s .o r g /o l e
MARKET REPORT
Price and performance key to laser projectors
Most visible light lasers have to date been used for laser light shows, medical, indus-trial or military applications. The low vol-umes and relative price insensitivity of these markets has kept the prices of these visible lasers high. To enter the display market, laser developers have been forced to look at new designs with radically dif-ferent price/performance ratios. Insight Media has evaluated these lasers and fore-cast their application to mass-market dis-plays through to 2012.
Currently, the only commercially avail-able laser projection systems are expen-sive and intended for the visualization and simulation markets. Jenoptik and Evans & Sutherland are the two major manufactur-ers of laser-based projection systems, with Jenoptik targeting primarily the aviation simulator market, and Evans & Sutherland the planetarium market.
Neither company will reveal the price of these laser projectors as they are always sold as part of a system, but they are certainly more than $150 000 (7101 000) each. This compares with perhaps $35 000 for an equivalent non-laser projector targeted at the visualization or simulation market. The main added value that laser projectors bring is extremely high contrast, which is crucial when showing the dark scenes that contain a few high-luminance objects typ ical of planetarium shows or aviation night-time training. Figure 1 shows an
Evans & Sutherland Digistar III laser pro-jector at the centre of a planetarium dome. The high resolution of this projector, 4 ×5 k or about 10 times the pixel count of a nor-mal digital cinema projector, allows a sin-gle projector to fi ll the entire dome.
Lasers and projection displays are a natural combination, as was recognized shortly after the invention of the laser. Fig-ure 2 shows a laser projector developed by Texas Instruments (TI) in 1966. The low étendue of lasers allows the use of very small microdisplays, or no microdisplay at all, which in turn leads to compact opti-cal systems. The Digistar III uses a linear MEMS array and the Jenoptik projector is like the TI projector in that the laser beams are raster scanned and the laser output is modulated to produce the image.
Vital statistics: lumensThe most compact projectors currently under development are pico-projectors. These projectors are typically the size of a mobile phone although some are small enough to be embedded into the phone itself. One would think that pico-projectors would benefi t the most from the small form-factor enabled by lasers. But, at the Consumer Electronics Show (CES) in Las Vegas, US, in January, of the 16 pico-projectors I saw, only two used all-laser light sources (Microvision and Scram Technologies) and one used a hybrid laser/LED source (Explay). The
others used LED solutions, including both RGB combinations and white LEDs.
Mitsubishi introduced a rear-projection TV (RPTV) using red, green and blue lasers for illumination at CES. This is the fi rst for-mally announced mass-market projector containing lasers, although Mitsubishi gave neither a specifi c availability date or a retail price for the system.
A pico-projector producing 10 lm would typically need 60 mW per colour at around 462, 532 and 630 nm for blue, green and red respectively. In comparison, RPTV requires about 3 W per colour. The require-ments on the lasers, other than the power output, are in general relaxed compared with current applications for visible lasers. For example, projector makers prefer multimode over singlemode lasers because the reduced coherence leads to reduced speckle at the projection screen.
Vital statistics: costVisible lasers of the correct wavelength have had suffi cient output power for display appli-cations for many years. The main barrier to the more widespread adoption of lasers in projection systems has been cost. Most of today’s commercially available high-power visible lasers are intended for markets that are relatively insensitive to cost such as laser light shows, medical or military. According to the price study in Insight Media’s Laser Report, a RPTV based on these lasers would
Low-cost lasers are being developed for the display market at previously unheard of price/performance ratios. Matthew Brennesholtz of Insight Media looks at the device
specifi cations for various projection applications and the key players in the market.
mechanical motion transformer
drumreflector
screen
torsionaltransducer
laser
Fig. 1 (left): Evans & Sutherland laser projector at the centre of a planetarium dome. Fig 2 (right): 1966 laser projector from Texas Instruments.
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16 OLE • March 20 08 • o p t i c s .o r g /o l e
MARKET REPORT
have to be priced at $90 000 or more, and poor sales would be expected.
An extensive study of laser prices was done as part of our laser report and a sample result is shown in fi gure 3. It shows the unit prices of 63 different commercially avail-able red lasers in the correct wavelength range in 2005 plotted with the prices of 83 commercially available red lasers in 2007. The blue solid line passes through or below prices from 2005 on the assumption that display makers would like the lowest cost laser available, with no special features or packaging. The blue dashed line is drawn at or below the 2007 prices.
The biggest price declines were at low-est output powers (1–20 mW). Price declines were more modest in the 60 mW – 3 W range, which is of interest to display makers. Information was too sparse at powers of 5 W and above to determine price declines. These higher powers are also of interest to projector makers – an electronic cinema projector is expected to require about 27 W of laser output per colour.
An additional problem is that display makers typically want a minimum of 100 000 sets of lasers. If you ask a tra-ditional laser manufacturer to quote for 100 k, 532 nm, 3 W green lasers, you are likely to get a blank stare. Potential elec-tronic cinema volumes are lower, perhaps 5,000–15 000 laser sets per year.
In order to forecast prices at these higher volumes, Insight Media has developed a price-volume model that extrapolates from low- to high-volume production. The model is based on the price-volume relationship of various optical and optoelectronic products, including the few lasers where the relation-ship is known. The 1–100 k high-volume price lines are derived from the unit price line using this model. Even the 100 k prices shown in the fi gure are too high for display makers: new laser designs are needed to pro-vide a price-performance breakthrough.
Key contendersToday, multiple companies are develop-ing low-cost lasers specifi cally for display applications. One of these companies is Novalux, which was acquired recently by Arasor (see OLE February p5). According to Greg Niven at Novalux, this means that the Novalux division of Arasor will focus on developing complete lasers, rather than selling the mounted laser epitaxial compo-nents to its licensees. This process will be aided by Arasor’s high-volume cleanroom manufacturing facilities in China.
Arasor also recently inked a $300 m joint venture (JV) with ZTE International fi nanced by the China Development Bank
to commercialize a range of laser-based display applications including televisions, projectors and mobile phones. Presumably, the lasers produced by the JV will be based on Novalux technology, such as the device shown in fi gure 4.
While Mitsubishi did not announce the source of its lasers, it is known to have a laser development programme. One can only assume that if all three lasers in the tele-vision introduced at CES were built by Mit-subishi, this would have been announced.
QPC is another company targeting lasers at the display market. It recently received a $1.15 m development contract from an unnamed CE company. This becomes a solid $11 m production order once QPC demon-strates that it can meet the specifi cations.
Another contender in the lasers for projection race is EpiCrystals of Finland. Its initial products are expected to have 60 mW per colour, just right for the pico-projector market. Its roadmap has samples going to strategic customers in 2008 and mass-production in Q1 2009. Lasers up to 500 mW are on the roadmap for Q3 2009 and the company is also planning lasers up to 3 W per colour. All of EpiCrystals’ lasers are based on a nonlinear conversion
similar to frequency-doubling of infrared wavelengths generated in GaAs, but spe-cifi c details are not available.
Other companies known to be developing lasers specifi cally for display applications include Bookham, Corning, Laser Light Engines, LightRush, Osram, Photo digm and Principia Lightworks. We assume that there are other “stealth” companies devel-oping projection lasers that Insight Media has not heard of.
LEDs are currently leading in the race for solid-state light sources for projection, with LED-based pocket projectors and RPTVs both commercially available. In addition, as mentioned above, most developers of fi rst-generation pico-projectors are using LEDs rather than lasers. LED believers claim the following major advantages over lasers for projection displays: availability of red, green, blue and white LEDs; reduced costs; no safety hazards; reduced speckle at the screen; high effi cacy of current LEDs; and the potential for LEDs with still higher effi cacies. Laser advocates can give con-vincing counter arguments to all of these points, but only time and the marketplace will determine which technology wins.
The projection market is currently dom-inated by high-intensity discharge lamps, such as the UHP from Philips Lighting. The lead that LEDs currently have in the projection market could change as the lasers under development come on the market. One reason that LEDs are ahead of lasers is the huge investment in LED research and development for non-dis-play applications. There are many mass-market applications for visible LEDs and the synergy between LEDs for illumina-tion and LEDs for displays is strong.
On the other hand, there are relatively few mass-market applications for visible lasers so the developments have been going slower. As companies like Arasor will testify, there is money available for laser development and Insight Media expects that these lasers will arrive on the market, probably sooner rather than later.
Matthew Brennesholtz is a senior analyst at Insight Media. For more information, e-mail [email protected] or visit www.insightmedia.info. The 2007 Insight Media Laser Report covers technical, cost and safety issues relating to the use of lasers in projection displays. Insight Media has a similar report on the technology, performance and cost issues relating to the use of LEDs in projection displays. The reports would be invaluable to anyone interested in the technology, human factors, economics or markets for solid-state light sources in projection applications.
cost
($
)
1,000,000
10000
100,000
10,000
1,000
100
10
1
0.1
0.01
100010010
CW output (milliwatts)
unit 2005
unit 2007unit 2005
1k 2005
100k 2005
1k 2007100k 2007
unit 2007
Fig. 3 (top): 2005/2007 red laser prices. Fig. 4 (bottom): 3 W output laser package from Novalux.
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17
CMOS MODELLING
OLE • March 20 08 • o p t i c s .o r g /o l e
Faster modelling speeds CMOS sensors to marketComputer models of what happens when light hits the pixels of a CMOS image sensor are so complex that each simulation can take days to run. Tim Hayes hears how recent advances in software and hardware can speed up the process by a factor of twenty or even more.
Optoelectronics manufacturers are under constant pressure to produce higher per-formance devices while also shortening the time taken to develop them. CMOS image sensors, which are widely used in camera phones, webcams, digital cameras and camcorders, have to pack more pixels into each new generation of device, while remaining cost-effective to produce.
Effective computer modelling is an essen-tial part of this development process, ena-bling producers to simulate critical aspects of the process and the device design. For CMOS image sensors these simulation tasks include not just process optimization, but also electrical and optical analyses to model parameters such as dark-current, microlens design and, crucially, cross-talk analysis.
The complexity of the devices means that such modelling is a demanding operation. “Over the last few years there has been growing interest in simulating CMOS image sensors, as the number of pixels in these applications continues to rise,” said Ric Borges, senior manager of prod-uct marketing at Synopsys, a developer of semiconductor design software. “But that increase in pixels has meant that the number-crunching involved has become formidable. It could take two or three days just to run one single simulation.”
A hardware solution has now been devel-oped that has a dramatic effect on the time taken to complete these models. It links Syn-opsys’ TCAD Sentaurus Device simulation software with the ClusterInABox Quad Q30 workstation made by Acceleware, design-ers of special purpose software/hardware acceleration products. The result is claimed to be a dramatic speeding up of electromag-netic simulations of optoelectronic devices, through Acceleware’s development of mul-tiple-thread, massively parallel processing in the system hardware. “The value we put in is by enabling applications to run in a massively parallel way, and that gives a per-formance boost,” commented Rob Miller, vice-president of marketing and product management at Acceleware.
Growing complexityIn designing a CMOS sensor, the main parameters to simulate are diffraction and interference. “They’re both very important, since the relative sizes of the structures are now so small,” observed Borges. “There could, for example, be some charges in the silicon that are meant to register a blue sig-nal but which are actually collected by the red pixel, adding to the noise.”
The wavelength of incident light is of the same order of magnitude as the dimen-sions of the pixels, so geometrical optics is not suffi cient to predict what will hap-pen. Instead, a full solution to Maxwell’s
equations that can treat interference and diffraction in full-wave optics is required, and that is where the computational complexity comes in. Solving Maxwell’s equations involves a highly accurate numerical method called fi nite-difference time-domain (FDTD) analysis, which can cover a wide frequency range with a single simulation run.
FDTD simulations in the past have typ-ically required tens of hours to fully char-acterize a CMOS image sensor design in 3D, but Acceleware’s hardware acceleration can drastically improve things. “Accel-eware’s founders are experts in this fi eld,
Simulation Size (millions Simulation time Simulation time Speed-up of cells) (software) (hardware acceleration) factor 1-pixel CIS 0.36 3 min 53 s 1 min 46 s 2×(very small)1-pixel CIS 3.74 32 min 58 s 4 min 21 s 8× (small)1-pixel CIS 13.38 2 h 7 min 11 min 17 s 11× (medium)1-pixel CIS 31.08 13 h 23 min 21 min 38 s 37× (large)4-pixel CIS 242 48 h 37 min 19 h 27 min 2.5×CIS: CMOS image sensor. Data: Synopsys/Acceleware
Selected benchmarks
Left: three-dimensional model of a typical pixel. Right: light intensity as it propagates through the pixel.
Syn
op
sys
Syn
op
sys
18
CMOS MODELLING
OLE • March 20 08 • o p t i c s .o r g /o l e
who fi rst ran into these issues while at uni-versity and looked for ways to accelerate their research,” said Miller.
“There are some details of the CMOS process that need to be fi ne tuned for optical applications, and there is a level of complex-ity in doing that even when designing just a single pixel,” explained Borges. “When trying to model the interplay between four pixels or more the simulation’s complexity grows rapidly and you need a lot of high-end analysis.”
Modelling the real worldThe use of simulations in the development process for a CMOS image sensor usually follows a set sequence. “Simulation of a sin-gle pixel is done fi rst, to get the major details correct,” said Borges. “Factors such as the colour fi lter, the shape of the lens and the photodiode piece within the silicon are all modelled to see what their effect will be.”
Once the single pixel is optimized, multi-pixel simulations can begin. The typical benchmark is to simulate four pixels, and
at this stage modelling the extent of opti-cal cross-talk between pixels becomes crucial. “A typical scheme for RGB would be a four-pixel sensor with one red pixel, one blue pixel and two green pixels. So, for example, we will simulate covering three pixels and shining light on the fourth to see if any signal is registered in the three covered pixels,” said Borges.
Other simulations model real-world effects. “There are good reasons for simu-lating light hitting the sensor at an oblique angle to see what the impact of incident angle is on performance, since that’s a situ-ation similar to the sensor’s environment in a commercial application,” noted Borges. “At some point the angle will be shallow enough to stop the sensor working properly.”
The possible time-saving provided by the new hardware acceleration during these simulations can be considerable. Figures from the companies claim a halving of the simulation time for a small one-pixel CMOS image sensor of 356 000 cells. For a more complex single pixel CMOS image sensor with 31 million cells, the simulation time is said to drop from nearly 13.5 hours with-out the acceleration technology to 22 min-utes, some 35-times faster.
After reaching the optimal configur-ation, the final detail will be to take account of manufacturing tolerances. “The shape of the lens and its location may vary, drifting around somewhat depend-ing on how tightly controlled the manu-facturing process is,” said Borges. “So another purpose of the modelling analysis is to understand the impact of, for exam-ple, the lens being misaligned on top of the photodiode and what effect that would have on performance. Overall there will be an incremental scale of simulations, start-ing with modelling the simplest pixel units and ending with simulations of these real-world manufacturing variables.”
As Borges points out, the CMOS image sensor market is very competitive. The overall development process will actually involve a sequence of several individual development cycles, and simulation can help reduce the number of these cycles or assist with designing experiments that home in more efficiently on the proper optical design.
“Time is of the essence, and if you can get to market a couple of months sooner than your competitor then that’s a really big deal. Typically you can count on it taking between one and two years for a manufac-turer to develop a new product and bring it to market. Using simulations can allow developers to shave six months off that period, and that’s huge for them.”
19OLE • March 20 08 • o p t i c s .o r g /o l e
ASK THE EXPERT: KISHAN DHOLAKIA
Optical trapping moves towards microfl uidics
Kishan Dholakia heads the Optical Trap-ping Group at the University of St Andrews in the UK. His pioneering research into opti-cal landscapes has enabled complex pat-terns of light to sort, separate or transform many molecules or cells at once. Applica-tions that benefi t from this research range from single-cell analysis to fundamental studies of light.
Can you summarize how optical trapping works?If we focus a laser beam to a small spot of the order of 1/1000th of a millimetre, we can form a trap. A transparent object or bead will refract light causing a change in the light’s momentum. This attracts the bead to the centre of the laser point where an equal amount of light is refracted in all directions. Some light is refl ected, which means that the fi nal equilibrium position of the sphere is close to, but not exactly at, the beam focus.
Why is it important to pursue the development of this technology? Optical tweezers have made the trans-ition to become an exceptionally powerful interdisciplinary tool. Since its conception in the mid-1980s, it has revolutionized our understanding of molecular motors in single molecule biophysics as well as mak-ing a huge impact in colloidal physics and fundamental studies of light. It is important to sustain the momentum of the fi eld as it is diffi cult to think of another technology so versatile and widely applicable. With improvement, new and exciting applica-tions are emerging, including those in microfl uidics and single-cell analysis.
What are the main applications and when do you expect them to occur?There are studies appearing that can meas-ure angstrom-level motion and femtonew-ton or smaller forces. Major advances are likely so that technology can do this in a more regular and simplifi ed manner, and hopefully in the next few years will become a mainstay in biology laboratories.
On a larger scale level, I expect applica-tions for organizing and arranging par-ticles to advance. If we can organize cells into certain arrays, then we can look at cell differentiation and even tissue growth. This is likely to grow in the next year with multiple traps giving insight into colloidal systems such as complex solvent/particle mixtures, as well as glass systems. We might even see tweezers making a bigger impact in self-assembled structures.
Multiple traps can create light patterns similar to a large array of egg boxes and these are commonly known as “optical landscapes”. This technology is relatively new and will allow for new forms of sort-ing. If used in combination with other sorting and separation techniques in the microscopic scale, some exciting new ways to separate, probe and select cells in micro-fl uidic environments could be found. This will help develop new types of microchips.
Until recently, the area of metal nanopar-ticles and nanowires had been relatively unexplored. I believe that this area will see a rich advance in the next few years where we will understand and organize nanopar-ticles into arrays and gain new insight into light-metal interactions.
Traps are also becoming useful in mov-ing small droplets and microcapsules. This is likely to lead to new forms of microreac-tors and greater understanding of reaction dynamics – perhaps the world’s smallest “test tube”? Traps will also play a more prominent role in aerosol studies.
What would you say is the most important recent advance?This is a hard one – can I pick two? The Block group at Stanford University in the US is using optical tweezers to measure angstrom-level displacements by reducing the noise and vibration in the system. This is amazing.
Another important advance is the emergence of multiple traps and the new applications that this is creating such as multicell analysis, cell sorting and cell organization.
What are the key challenges left to overcome in this fi eld?Calibrating each trap within an array of multiple traps and combining this with technologies such as confocal spectro-scopy, multiphoton microscopy, fl uores-cence and Raman. Understanding how a wider array of objects such as nanoparti-cles may be trapped and integrating optical systems with microfl uidics for real biomed-ical science on a chip.
What do you expect the next big breakthroughs to be?Optical trapping has been progressing steadily. In the short term there will be a greater uptake of multiple calibrated traps as well as the development of a bio-workstation where trapping is readily incorporated with other modalities such as imaging and spectroscopy. Advanced particle tracking and microscopy meth-ods will add value and we may gain new insight into Brownian dynamics.
On a longer time frame I would expect to see a deeper understanding of the light-matter interaction leading to the creation of larger, truly self-assembled structures using tweezers.
A variety of schemes will come forward that will integrate optics and microfl uidics, and I expect to see major advances. This will lead to a compact optical microfl uidic device that will look at sourcing anal ysis and will prove to be a very strong and power ful device in years to come.
Optical trapping is a rapidly advancing and versatile fi eld. Kishan Dholakia speaks toMarie Freebody about the breakthroughs so far and his expectations for the future.
Predicting steady progress: Kishan Dholakia.
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20 OLE • March 20 08 • o p t i c s .o r g /o l e
OPTICAL MANUFACTURING
There are several common misconceptions surrounding high-precision manufacturing. Jacqueline Hewett speaks to John Stack and David Erickson of Zygo to get a clear picture of what is involved and the benefi ts of adopting this approach.
Finding hidden value in high
Deciding whether your application requires high-precision manufacturing is a daunt-ing task and raises a number of questions. What exactly is high-precision manufac-turing and what are the advantages of this approach? How much will it cost? Will it save time? What levels of performance can I expect from the fi nal optical assembly?
These are questions that John Stack, the president of Zygo’s Optical Systems Divi-sion, and David Erickson, a senior scientist in that division, have heard before. Both believe that many people are not aware that they need to move to high-precision manufacturing and the added value that making this jump can bring.
“There is real economic value in high-precision manufacturing,” Stack told OLE.“Done properly, it reduces the time-to-mar-ket and the value of that is phenomenal. Our expertise enables customers to get their products to market faster and ahead of their competitors. Value-over-time is also import-ant and this approach tends to keep the product viable in the market for longer.”
High-precision basicsThere are distinct differences between precision and high-precision manufac-turing. “Precision optics fi t together and achieve their desired performance using a ‘drop-in’ component model,” explained Stack. “Although the goal is always to push for drop-in production methods, it is ultimately the need for metrology-based manufacturing that drives a system towards high precision.”
Metrology and feedback are the essence of high-precision manufacturing. “The feedback takes what is seemingly imposs-ible and makes it possible and predictable,” explained Stack.
In Erickson’s career, he has seen optical designs that look as though they cannot be manufactured. “Metrology is the key,” he said. “A good test of a high-precision device is that you could not reverse-engineer it and get the same performance. Metrology introduces certain compensations as the system is assembled.”
A subtle point here is the difference between making things that are high
precision in a laboratory versus a factory setting. “If I was making a one-off device in the lab I may go through many iter-ations, but this is not cost effective in the real world,” explained Stack. “High-pre-cision manufacturing includes the ability to build high-precision assemblies in a factory setting. At a basic level, this is the ability to assemble high-precision devices with skill technicians.”
Does my application require high-precision manufacturing?Although this is a hard question to answer in general, both Stack and Erickson agree that there are some common factors that point towards high-precision manufac-turing. The fi rst question you should ask is “does my assembly require active align-ment” followed by “is there active com-pensation involved in the alignment”. It is also important to decide if you require the feedback that metrology loops and use of design software, such as CODE V, brings.
Other clues are a design that has multiple axes or multiple paths and has to operate over a wide spectral range (from ultraviolet through to near-infrared). A system run-ning at very low f-numbers that operates at the diffraction limit is also a contender. In other words, there are many factors that point towards high-precision manufac-turing but it ultimately depends on the product and its end application.
“In order to make the system work, you cannot rely on the parts alone,” con-cluded Erickson. “You have to look to other techniques that marry the components and allow the whole ensemble to play together.”
Example applicationsAs a metrology expert, Zygo has been involved in a number of high-precision manufacturing programmes and one industry that is particularly reliant on this skill is the medical market. For example, Zygo is a key player in developing high-end medical laser delivery systems for refract-ive eye surgery.
“The medical laser delivery market requires diffraction-limited beam qual-
ity,” explained Erickson. “These are often scanning systems that require consistency over a specifi c depth of focus. Thus there is a volume over which a set level of precision must be maintained.”
The fi rst step in the process is to assem-ble all of the high-precision components that make up the system in what is known as a “dry stack”. Zygo then performs inter-ferometry on the stack, feeds that infor-mation back into the design code and fabricates compensation spacers that bring the overall lens back into specifi ca-tion – all on the factory fl oor.
Zygo has also been involved in the devel-opment of production photolithographic lenses. In this example, the diffraction-limited performance and distortion requirements over a large fi eld of view were crucial. “We were working over a large lin-ear fi eld of view requiring 0.5 μm distortion or better,” said Erickson. “We built a distor-tion testing device that can measure distor-tion in tens of nanometres. We also fi gured out how to measure the wavefront in-situand in tandem with the distortion. These lens systems can have between 20 and 30 elements, and will end up in our produc-tion facility with volumes of hundreds per year – its no small feat.”
One final example is Zygo’s work on microscope objectives with a bandwidth of 190–700 nm. “The fi eld of view was rela-
Head-mounted displays (left) and assemblies for the National Ighigh-precision manufacturing projects that Zygo has been involv
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21OLE • March 20 08 • o p t i c s .o r g /o l e
h-precision manufacturing
tively small but the spot needed to be dif-fraction limited,” said Erickson. “We also had to control certain aberration groups (certain Zernikes) to achieve the required performance.”
As is evident from the photolithographic lens example, Zygo typically builds spe-cialized tools that are customized for the end application. It is also crucial to con-sider the fi nal environment that the sys-tem will be used in.
“Not only do you have high-performance glass, but you also work with high-perform-ance metal in the packaging,” emphasized Erickson. “This goes right through from the metal to the adhesive that you are using. Knowing what is going to happen in the fi eld is all part of the high-precision manufactur-ing process. You may spend as much time working on that as you did on the original lens design.”
Cost and other misconceptionsOne of the most common misconceptions is that high-precision manufacturing is cost-prohibitive. “There is an interest-ing distinction between cost and value,” said Stack. “It’s the value of the part that counts. We have found that the value of higher performance balanced with good manufacturing techniques actually turns out to be a more defendable space.”
Other factors that influence costs are
tooling and the order in which the system is assembled. “When we develop a prototype, we throw a lot of tools at it,” said Erickson. “When we make it in production, we refi ne the approach using our design for manu-facturing and assembly (DFMA) process. We take various things out through the DFMA process and the fi nal order in which you put something together drives cost. We take all of this into account and assemble the system in the right order to make it cost-competitive.”
It is important however to build enough time into any product roadmap to allow the DFMA process to run its full course and reap the maximum benefi t. “Another mistake that I have observed, partic-ularly in time-sensitive markets, is a lack of appreciation of the time it takes to turn a prototype into a product,” said Stack. “It is hard to apply a rule of thumb here as it all depends on the production quantities, but this error ultimately slows down the launch of the product.”
According to Stack, after cost, one of the biggest mistakes is thinking that there is a high percentage of completion once the optical design is on paper. “This is a very poor assumption,” he said. “The customer’s functional specifi cations and requirements do not necessarily match directly, or eas-ily, to what are typical optical tolerances such as MTF. The trick is to help customers
achieve functionally robust products with-out over specifying the optical require-ments. This confi dence is almost always achieved by providing highly refined metrology and production techniques at a system level.”
This mismatch between the process capa-bilities and the system requirements is a common problem says Erickson. “Custom-ers often miss the limitations of optical shops and are surprised by the experience as they go through the fi rst system build,” he said. “There has to be a high degree of collabora-tion. As we work through the specifi cations, there has to be give and take to support the customer’s cost requirements, manufactur-ing capabilities and time to market.”
ConclusionA lot of work goes on behind the scenes in high-precision manufacturing that is not immediately obvious to scientists who have never been through the process. Once you have made the leap of faith, committed to putting your product through this manufac-turing approach and overcome the stigma of cost, the rewards are clear. “We are able to streamline things but you will never elim-inate the need for the metrology feedback in high-precision manufacturing,” concluded Stack. “We keep working the DFMA process and the encouraging thing is that it starts to converge to precision pricing.”
gnition Facility (top right, bottom left) are just two examples of ved in. Zygo’s distortion tester is shown bottom right.
Fibre reels, clips, uniter holdersand speciality patchcords fromCambridge Optical Sciences:
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OLEMar08p22.indd 1 26/2/08 14:58:00
23OLE • March 20 08 • o p t i c s .o r g /o l e
SLAB LASERS
Flexible slab laser gives industry an alternative
Today’s industrial applications tend to look to fibre, disk and diode-pumped solid-state as the laser of choice. But one German company pioneering a different approach is EdgeWave, which believes that slab lasers offer a feature set not to be found in any of its competitors.
According to Keming Du, chief executive offi cer and founder of EdgeWave, the most important advantage of its Innoslab diode-pumped slab design is the unique combi-nation of features that it offers. “Innoslab provides short pulse length, high repeti-tion rate, high pulse energy and scalabil-ity, while maintaining high beam quality,” he told OLE. “We also have the ability to change the beam profi le from a line to a square or circular shape.”
Du began pioneering the Innoslab design back in 1996 during his time at the Fraunhofer Institute of Laser Technology (ILT) in Aachen. So convinced by the com-mercial potential of the design, he chose to form EdgeWave as a spin-off from ILT in June 2001. Since then the company has gone from strength to strength and has customers all over the world using slab lasers for applications ranging from solar-cell scribing to glass drilling.
What is a slab laser?As its name suggests, a slab laser uses a plate with a rectangular cross-section as the gain medium. This shape allows slab lasers to avoid the optical distortion that is often associated with rod lasers.
“When a rod laser is pumped, energy is deposited within the crystal causing it to heat up. This heat is conducted in two dimensions from the middle of the crys-tal to the surface, causing deformation of the laser beam and limiting its quality,” explained Du. “The crystal in a slab laser however, is a very thin plate of the order of 1 mm in height. This limits heat con-duction to just one dimension so that you don’t have the same level of stress or opti-cal deformation.”
EdgeWave advantagesWhile retaining all of the benefi ts of a tra-ditional slab laser, Du pushes the design to another level. His key breakthrough uses partial pumping of just one layer of the slab crystal by an arrangement of stacked diode lasers. The pumped volume has a linear cross-section and only partially covers the cross-section of the slab crystal.
“The crystal has a cross-sectional area of 12 ×1 mm. Instead of pumping the entire crystal, we focus the pumping beam to 12 × 0.4 mm using a microlens array,” explained Du. “By pumping a 0.4 mm fl at layer in the middle of the crystal we reduce the optical distortion that occurs at the corners of the slab where the geometry of the crystal structure is broken.”
Thanks to a short resonator length of just 70 mm, the end result is a high-qual-ity beam and pulses with a duration of around 10 ns. By increasing the width of the crystal, the power and pulse energy can be increased without changing the beam profi le or quality.
The crystal is typically Nd doped, how-ever, unlike disk lasers any type of crys-tal can be used such as Nd:YLF, Nd:YAG or Nd:YVO4. Disk lasers require a crystal with a very high absorption coefficient and doping capacity. “For most applica-tions, Yb:YAG is the only crystal that can
be used in disk lasers as it can be doped to 20% maximizing absorption in the thin disk,” explained Du. “In a slab laser we can use any type of crystal and absorption can be increased by increasing the length.”
Du believes that his Innoslab concept was made possible thanks to the evolution of high-power diode lasers. “Lamp-pumping beams do not have enough energy or power to be concentrated into a line shape,” com-mented Du. “A diode laser, however, can produce a high-quality line-shaped beam. Combining this with the partial pumping technique means that you can generate a high-quality laser beam.”
Apart from high-power diode lasers for pumping, fi gure 1 shows the other compo-nents that are key to the Innoslab design. A planar waveguide and microlens array are used to homogenize and focus the pumping beam before it reaches the crys-tal. A dichroic-coated resonator mir-ror (M1) transmits the pumping light at 800 nm and refl ects the laser emission at 1064nm. Another resonator mirror (M2)is placed at the other end of the crystal.
Pulses are produced at a repetition rate of 50 kHz using a Pockels cell (electro-optic Q switcher) and a polarizer. “The Pockels cell contains a BBO crystal, which rotates the plane of the laser beam when a voltage is applied,” explained Du. “The subsequent
A laser that produces high-quality light in a variety of beam shapes could be adapted to suit a range of applications. Marie Freebody speaks to Keming Du of EdgeWave to fi nd out more about its slab laser technology and the areas that could benefi t from the design.
output beam
modulatorpolarizerslabbeam shaping
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Fig. 1: The Innoslab design uses partial pumping of the slab crystal to reduce optical distortion.
24 OLE • March 20 08 • o p t i c s .o r g /o l e
SLAB LASERS
polarizer will then block the light, effect-ively closing the cavity. When the voltage is switched off, the cavity opens providing a short pulse of laser light.”
A variety of wavelengths including the second and third harmonics can be gener-ated in this way. “Our lasers can produce light at 1064, 532 and 355 nm with average powers of 600, 120 and 20 W respectively,” commented Du. “We are currently working on increasing the power in the second har-monic (532 nm) from 120 to 300 W.”
Beam shapesMany lasers require additional effort and cost to produce different beam shapes. Innoslab lasers on the other hand can pro-duce a variety of beam shapes without the need for diffractive optics or a microlens array. “We can get a square top hat down to 30 ×30 μm, which is diffi cult to obtain using a microlens array or diffractive optics,” commented Du.
A circular (Gaussian) beam and a square (2D top hat) beam are produced using a
cylindrical telescope to make the sides of the beam symmetrical. For a Gaussian beam an additional spatial fi lter is used to eliminate the side lobes. “The natural beam produced is a line-shaped beam that means that the intensity distribution along the line is homogeneous and across the line is Gaussian,” explained Du. “This is used for a lot of applications such as for ablation processes and for solar-cell scribing.”
ApplicationsThe ability to tailor the beam shape means that Innoslab lasers can be adapted for use in applications such as drilling, structur-ing, cleaning, polishing, surface marking, sub-surface engraving, cutting and rapid prototyping.
One application that is only possible thanks to Innoslab’s unique combination of properties is glass drilling. Glass is typ-ically drilled from above using excimer or CO2 lasers. Innoslab, however, focuses the beam through the glass to a very small spot on the opposite surface.
“This allows the ablated material to escape freely without disturbing the path of the laser beam leading to effect-ive drilling,” commented Du. “The pro-cess requires high pulse energy and short pulse duration, as well as a high-quality beam for focusing to a small spot.”
A line-shaped beam can be used to ablate a strip of material more effi ciently than using a circular beam. Similarly a square-shaped beam can be used for solar-cell scribing. Conventionally, a Gaussian beam is used, but thermal damage can be caused at the edges of the beam where energy is not high enough to ablate.
“By using a square-shaped beam, you can use much less energy to get a very well-defi ned boundary,” explained Du.
These images show the intensity distributions for a square (top) and line-shaped (bottom) beam.
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25OLE • March 20 08 • o p t i c s .o r g /o l e
TECHNOLOGY TUTORIAL
Iterative steps ensure successful LED lighting
Light-emitting diodes (LEDs) have been commercially available since the 1960s and have, over time, become common-place. Indeed, one would be hard pressed to think of a modern electronic device that does not use an LED. Mobile telephones, televisions, computers and even coffee makers all use LEDs for tasks such as “on/off” indication or backlighting of keypads. But while these LEDs are useful, they are of limited value to the general lighting mar-ket due to their low current and low-power handling capabilities.
Unlike indicator LEDs, power LEDs are designed to operate at higher currents and in turn produce far more light. Since their introduction by Philips Lumileds in 1999, power LEDs have become potential replace-ments for most conventional illumination light sources. Because the technology is so different to the familiar fi lament bulb, many wonder how LEDs create white light, how the technology is evolving and what is required to design a solid-state lighting sys-tem. This article addresses these questions.
The colour of white lightThe colour of white emitted by a white light source depends on the relative strength of each constituent wavelength, known as the source’s spectral composition. Colour temperature (CT), a simplifi ed way of clas-sifying the colour of white light, relates a white light’s tint when compared with the colour of light emitted by a blackbody radi-ator as it is being heated. For this reason, CT is measured in degrees Kelvin.
A lower CT means that the white light is warmer and contains more red, while a higher CT represents light that is cooler and bluer in appearance. In comparison, the CT at sunrise and sunset is around 2200 K, while that of the Sun at midday is around 5500 K.
Very few light sources match a blackbody radiator exactly. To accommodate for devia-tions from this ideal source, a factor known as the correlated colour temperature (CCT) is commonly used to describe white light. As
the name suggests, CCT refl ects the nearest colour temperature. It is worth noting that a CCT is calculated based on its chromatic-ity coordinates when compared with the ideal blackbody radiator (also known as the Planckian locus).
When designing a lighting system, one of the fi rst elements that you should consider is the CCT. Studies indicate that people feel more comfortable when the ambient lighting is similar to the Sun’s CT at that time of the day. For that reason, cool CCT is favoured in work environments during the day, while warm CCT, the colour of morn-ings and evenings, is favoured at home, in restaurants and similar environments.
A simple method to describe white light was established in 1931 by the Interna-tional Commission on Illumination (CIE). The resulting CIE 1931 chromaticity dia-gram illustrates the way that the human eye experiences light using an x-y coordi-nate system. In the graph, which is shown in fi gure 1, the Planckian locus (the black line in the middle) is visible as are the rela-tive positions of all visible colours and a 2D description of each colour point (x, y).
Power LED manufacturers expand the area around the Planckian blackbody locus and defi ne x-y boundaries represent-ing “bins” of CCT, as shown in fi gure 2. These are typically called binning charts and describe the CCT and tint of the white LEDs that each manufacturer produces.
Binning and labelling is the process of separating LEDs based on their various characteristics and assigning them to a specifi c bin with a unique code. Bin selec-tion can be an important consideration when designing a lighting system.
Creating white lightThere are several ways of making white light with power LEDs. One method, which most televisions, computer monitors and other large-area displays employ, is to com-bine red, green and blue light to make white. Another approach is to combine blue or ultraviolet light with a phosphor (or several phosphors) to make white. The latter, when using a single phosphor, is known as the binary complimentary technique.
There are several ways of combining the phosphor and the LED. One method involves dispensing a drop of phosphor onto the light-emitting semiconductor. As the drop is thicker in the middle of the semiconductor chip, less of the blue light is emitted and the CCT is warmer in appear-ance. As we move along the top surface of the semiconductor, more blue light escapes near the edges and there is a shift in CCT to a cooler range. This approach is frequently called a “glob” top and can be recognized by the telltale variance in CCT over the
White LED technology is evolving rapidly. Pat Goodman and Christos Sarakinos discuss the iterative process that all developers should follow when designing a lighting system.
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Fig. 1 (top): the CIE chromaticity diagram plots the way that the human eye experiences light. Fig. 2 (bottom): a correlated CT binning chart.
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26 OLE • March 20 08 • o p t i c s .o r g /o l e
TECHNOLOGY TUTORIAL
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viewing angle of the part.A second method conformally coats the
phosphor onto the light-emitting semicon-ductor, which provides a much more uni-form CCT over the viewing angle. The two approaches are shown in fi gure 3.
A recent breakthrough, Lumiramic phos-phor technology (Lumiramic), provides even better CCT control than conformal coating. Lumiramic technology combines a ceramic phosphor plate with a thin-fi lm fl ip-chip. This process is said to minimize the tint variation and produce white LEDs with a specifi c CCT more consistently. This reduction in variation enables high-volume usage of power LEDs in luminaires.
Capability and technologyLED technology is advancing rapidly and identifying state-of-the-art LEDs requires constant attention to the many releases and claims from scientists and manufacturers. It can be challenging to see through all of the marketing hype and appreciate what characteristics defi ne a good power LED.
Perhaps the fi rst characteristic to con-sider is the light output or fl ux. Over the past two years, light output from white power LEDs has more than doubled, but
just how much light is emitted from a white power LED can be diffi cult to understand.
Datasheet numbers are based on test-ing at a specifi c current, temperature and
time period, and these are often very dif-ferent to the conditions found in the end application. It is critical that all fl ux claims and data sheet numbers are considered and evaluated for what they are – a starting point. By applying readily available tools and calculations, it is possible to determine how much light will be emitted in an actual application before it is even built.
The effi ciency of a power LED is an import-ant measure as today even more attention is paid to the energy-saving potential of solid-state lighting. Effi ciency, expressed as lumens/watt is a calculable result.
Because power LEDs vary signifi cantly between manufacturers, it is again crit-ical to calculate the performance in the intended application. It is not uncommon to discover that a comparison of datasheet values results in entirely different conclu-sions when comparing LEDs in the target application. Crucially, the effi ciency of an LED can be dramatically different to the effi ciency of a complete solution employ-ing that LED. Drive electronics, thermal engineering, optical design and operating environment all have an impact on a sys-tem’s overall effi ciency.
The fi nal point to consider, and possibly the most important, is the reliability of the
conventional phosphorcoating method
Philips Lumileds patentedconformal phosphordeposition process
phosphor is unevenly distributed
phospher is evenly distributed
varying shades of white highly uniform white colour
Fig. 3: this illustrates two ways to create a white light source by combining an LED and a phosphor.
Sim
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“Light output from white power LEDs has more than doubled in the last two years.”
OLE • March 20 08 • o p t i c s .o r g /o l e
TECHNOLOGY TUTORIAL
power LED. While the myth of 100 000 h usable lifetime is still repeated, some power LED manufacturers are providing infor-mation that details lumen maintenance of 70% at 50 000 h. One company, Philips Lumileds, has gone a step further and pro-vides complete reliability data with a 90% confi dence basis. This means that develop-ers can design arrays of devices or systems with the same understanding that they have for today’s conventional light sources.
From idea to applicationThe question asked most frequently is: how do I design my system? Strictly speaking, there is a preferred way to achieve a robust design. It is an iterative process as the design is tweaked and has proven successful with many solid-state lighting companies.
Defi ne the light output requirementFor a general illumination system, the fi rst step is to determine the size of the area that needs to be illuminated, the distance between the source and the surface and the desired light density on the surface. From here, the light output requirements of the source can be calculated easily.
Calculate your target effi ciencyThis step is critical because the result will dictate the drive current. Remember, all LEDs become less effi cient as they are driven harder and get hotter.
Select a power LEDThis selection must be based on both the light output requirements and the drive current. Great care must also be taken to select an LED with the appropriate reli-ability. For instance, a disposable product might not require the same lumen main-tenance or reliability as a medical applica-tion. The most common misconception is that all power LEDs are created equal. The simple fact is that they are not. Lifetime claims need to be substantiated by data.
Simulate the systemThe fourth step is to simulate the system, taking into account the various relation-ships between current, voltage, light, heat and lifetime. Future Lighting Solutions provides online tools that calculate the usable light of a system and allow compar-ison of LEDs and systems under different conditions (see www.futureelectronics.com/promos/lumileds/usablelight/). This simulation will help to determine the number of power LEDs required, the opti-mal drive current, thermal requirements, and much more.
PrototypingThe fi nal step is to develop and test a pro-totype. Ideally, this should be done using off-the-shelf and readily available com-ponents. First, the prototype should be
tested to ensure that the light output and effi ciency requirements have been met. It should then be tested to ensure that the thermal design is suitable and will enable the desired reliability.
ConclusionPower LEDs are continuing to displace other light sources in the general illumin-ation market. The comparison, measure-ment and implementation in applications are all signifi cantly different to the well-
understood process for conventional light sources. Following a few simple steps and utilizing tools specifi cally designed to help evaluate power LEDs will allow for simp ler, faster and ultimately more successful devel-opment of new and never before poss ible solid-state lighting applications.
Pat Goodman is a senior applications engineer at Philips Lumileds Lighting Company. Christos Sarakinos is a regional technical manager at Future Lighting Solutions.
LASER OPTICS IR OPTICS
www.lasercomponents.co.uk
OPTICAL FILTERSFIBRE OPTICS
DETECTORSDETECTORS IR
OPTO-ELECTRONICMEASUREMENTLASER DIODES
ACCESSORIES
Intelligent CamerasArea Scan Cameras Line Scan Cameras
www.basler-vc.com/pilot
10 New High Performance Area Scan CamerasCapture great images with your choice
of high quality Kodak or Sony CCD sensors
Available in VGA, one, two, and fi ve megapixel options
Fast readout times increase throughput and productivity
Eliminate frame grabber costs with a direct Gigabit
Ethernet interface to the processor
Benefi t from high bandwidth data transfer, cable
lengths up to 100 meters, and 100% compliance with
the GigE Vision standard
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4109_ad_OLE_pilot_1-1_page.indd 1 22.01.2008 12:24:19 Uhr
29OLE • March 20 08 • o p t i c s .o r g /o l e
PRODUCTSIf you would like your company’s products to be featured in this section,
send your press releases and images to Marie Freebody (e-mail [email protected]).
LCoS spatial light modulatorHamamatsu Photonics
Hamamatsu Photonics
has released the
X10468 – a liquid-
crystal-on-silicon
spatial light modulator
with a fi ll factor in
excess of 95% and a rise time of around 10 ms.
Boasting high diffraction effi ciency combined
with a high-precision phase modulation with
excellent linearity, the X10468 is said to
provide industry-leading performance. Potential
uses include optical wavefront correction,
aberration correction and laser-beam shaping for
applications such as microscopy, materials and
optical tweezers.
www.sales.hamamatsu.com
PhotometerGamma Scientifi c
The fl exOptometer from
Gamma Scientifi c is a
radiometer/photometer
designed to operate
as a standalone
instrument or as a computer-controlled, full-
function photometric, radiometric or fi bre-
optic measurement tool. The new model is
available with a single head or with up to four
interchangeable detector heads for optimal
fl exibility. The four-channel fl exOptometer
includes a touch-screen backlit LCD and is
confi gurable through USB, RS-232, RS-485 and
IEEE-488.2 interfaces. Ideal for testing and light
measurement applications, the fl exOptometer is
available in OEM volume.
www.gamma-sci.com
Digital line-scan cameraSensors Unlimited
The SU-LDH digital
line-scan near-infrared
camera from Sensors
Unlimited is now able
to capture 46 000 lines
per second at 1024
pixels, making it ideal
for Fourier domain optical coherence tomography.
Based on indium gallium arsenide technology, the
camera is sensitive to wavelengths between 0.8
and 1.7 μm.
The camera features high sensitivity, room-
temperature-stabilized operation and integrate-
while-read capability for faster readout speeds
with minimal dead time. Other applications
include hot glass and metals processing, remote
ground sensing, materials classifi cation and
sorting, and high-speed spectroscopy.
www.sensorsinc.com
Handheld spectrometerOcean Optics
The latest product
release from
Ocean Optics is
the Jaz – a family
of interchangeable
modular components including a light source,
rechargeable lithium-ion battery and up to eight
spectrometer modules. Users simply hold the
Jaz up to whatever they want to measure, view
the spectrum on the display and press save.
The display gives a rough idea of the emission
spectrum, which can then be viewed in more
detail by transferring the spectral data over to
a PC. Working in the 200–1100 nm wavelength
range, the Jaz includes a powerful onboard
microprocessor that eliminates the need for a
computer, as well as an OLED display, Ethernet
connectivity and an SD memory-card slot.
www.oceanoptics.com
QCW diode lasersJenoptik LaserdiodeJenoptik Laserdiode has unveiled a family of high-
power diode laser bars that are fully optimized
for quasi continuous-wave (qcw) operation at a
wavelength of 808 nm. The diodes use passive
cooling and the company says that for pulse
durations of up to 300 μs and duty cycles of up to
10%, peak powers can be as high as 300 W. Fast-
axis collimation is available on these devices.
The fi rm has also developed passively cooled
qcw stacks that can reach peak powers of up to
2.4 kW. Fast-axis collimation will be available for
these devices in the near future.
www.jold.com
High-power laser cablesFrank Optic Products
Frank Optic Products
says that it can supply
laser cables in all
performance classes
for applications ranging
from medical technology
through to spectroscopy
and analysis. Examples include externally cooled
beam delivery systems, autoclave-capable
laser cables, fi bre-optic beam delivery systems
with RFID technology and optoelectronic
safety installations in the 10kW range for high-
performance lasers.
www.frank-optic-products.de
PRODUCTS
OLE • March 20 08 • o p t i c s .o r g /o l e30
High Power Fiber Lasers > CW up to 200Watts> Pulsed up to 20Watts> 1550nm up to 10 Watts
CO2 Lasers> Air & Water cooled CO2 Lasers> Power from 10W up to 200Watts> ROHS Compliant
Laser Diode Modules> UV, Visible, IR> CW, Pulsed or Modulated> Circular & Elliptical Beam
DPSS & YAG Lasers> Compact Module UV to IR> High Power YAG up to
1600Watts
www.bfiopt
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Photonics for Europe
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+33(0)1 60 79 59 00
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BFi OPTiLAS European Offices :
Laser Sources
Unique performances- beam quality M² < 2- pulse energy up to 60mJ- pulse length down to 4ns- peak power up to 6MW- pulse rep. rate up to 150kHz- average power up to 600W- wave length 1064, 532, 355, 266nm
Circular Gaussian Beam:- precision micro machining- wafer scribing- rapid tool manufacturingLine shaped Top-Hat:- ablation, structuring, cleaning- pumping dye laser, OPO, Ti:Sapphire- annealing, sequential lateral solidificationSquare Top-Hat:- structuring, ablation, cleaning- data matrix marking- solar cell processing
Diode pumped INNOSLAB lasers
Innovative Laser Solutions
[email protected] www.edge-wave.com
Circular Gaussian beam
Tailored beam profiles
Favourable Applications
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Tunable laser systemSacher Lasertechnik
Sacher Lasertechnik
is now offering a new
generation of tunable
laser systems in the
Littman/Metcalf
confi guration. Branded
as the TEC 500 and TEC 520 Lion systems, the
products are quoted as having an optical output
power of up to 150 mW and both coarse and fi ne-
tuning modes.
Manual coarse tuning of up to 30 nm is
possible at 780 or 830 nm and fi ne tuning via a
piezo actuator gives a resolution of better than
10 MHz. The company also quotes a large mode-
hop free tuning range of up to 100 GHz, linewidths
less than 300 kHz and side-mode suppression
greater than 50 dB.
www.sacher-laser.com
Piezo-driven devicesNewport
The high-precision
AG-LS25 miniature linear
stage and the AG-PR100
polarizer rotator are
the latest additions to
Newport’s Agilis range.
The Agilis family now comprises a variety of piezo-
motor remote-controllable devices for laser optical
set-ups including mirror mounts, linear and rotation
stages, and an electronic controller.
Newport says that the non-resonant motor
inside the AG-LS25 makes small incremental
adjustments more predictable with a 50 nm
incremental motion capability. The AG-PR100 is
a polarizer rotator that features 360° continuous
rotation for 1-inch diameter waveplates and
polarizers. Precision motion is achieved thanks to
a proprietary ball-bearing that ensures better than
100 μrad wobble.
www.newport.com
FBG-based componentsTeraXionTeraXion has launched the PowerSpectrum
product line, which comprises high-performance
fi bre Bragg grating-based components. The
initial launch includes two fl agship devices, the
PowerSpectrum-HPR and the PowerSpectrum-
NLS. The HPR is a high-power refl ector that
is ideal for use in continuous-wave or pulsed
fi bre lasers up to 800 W. The NLS is an ultra-
narrowband laser stabilizer athermally packaged
with a standard or polarization-maintaining
fi bre. This product can be used to create a
high-performance light source where a high
level of wavelength stability is required. The
PowerSpectrum line includes other customized
devices such as pulse stretchers and
compressors for ultrafast fi bre lasers.
www.teraxion.com
PRODUCTS
OLE • March 20 08 • o p t i c s .o r g /o l e 31
People trust
Photon to
recommend
the right
solutions for
their unique
applications.
www.photon-inc.com/pro
NEED ABEAM
PROFILER?
NanoScan
Ultrafast laser systemFemtolasers
The Femtosource
scientifi c XL 500 from
Femtolasers produces
an output energy level
exceeding 0.5 μJ and pulses with a duration of
less than 50 fs. In combination with a repetition
rate of greater than 5 MHz, this yields an average
power level in excess of 2.5 W and greater than
10 MW of peak power at a centre wavelength of
800 nm.
The ultrafast laser system combines the
company’s dispersive mirror know-how with its
chirped pulse oscillator technology. According to
the fi rm, this set-up combines the advantages of
both ultrafast oscillators and ultrafast amplifi er
systems, while omitting their disadvantages.
The temperature-stabilized laser head measures
1240 ×540 ×208 mm.
www.femtolasers.com
515 nm laserCoboltThe Cobolt Fandango, a low-noise DPSS laser
emitting at 515 nm, is now available with up to
50 mW continuous-wave output power making
it ideal for fl uorescence analysis applications
such as spinning-disc confocal microscopy. Built
on a robust platform with a hermetically sealed
package, the Fandango has a noise of less
than 0.3% rms, a beam quality of M2<1.1 and
operates between 10 and 40 °C. The full system
typically consumes less than 25 W of electrical
power. The laser controller is available in a
CDRH version and as an ultra-compact remotely
controllable OEM model operating over digital
(RS-232) or analogue interfaces.
www.cobolt.se
Colour measurementArmstrong Optical
The RUBY non-contact
spectrocolourimetry
system from Armstrong
Optical can supply
up to 2000 spectra
per second. Typical
applications include analysing the refl ectance
of diffusing materials, the intensity and colour of
light sources and displays, and the transmittance
of fi lters and liquids.
The instrument consists of an optical
controller cabinet with a built-in light source
linked by a fi bre-optic cable to a remote
measurement head. Armstrong says that the
Ruby can be used as a hand-held or tripod-
mounted measurement instrument in a quality-
control laboratory, or as an in-process colour
measurement sensor on the production line
where its 80 mm working distance allows good
clearance for objects on conveyor systems.
www.armstrong.co.uk
free optics.org
optics.org
TechnologyBusinessProductsCompaniesRecruitment
BE PART OF THE GLOBALPHOTONICS COMMUNITY
LASERS, OPT ICS & PHOTONICS RESOURCES & NEWS
Untitled-7 1 26/2/08 11:42:19
OLE • March 20 08 • o p t i c s .o r g /o l e
PRODUCTS
33
Leister ProcessTechnologiesAxetris DivisionSwitzerland Phone +41 41 662 74 [email protected]/axetris
Laser diode collimation
Beam homogenization
Wavefront sensor optics
Fibre collimation
Custom micro-optics
ISO 9001:2000
Micro-Optics Solutions
Multibar modulesDILAS
Fibre-coupled multibar
modules delivering
130 or 200 W via a
200 μm fi bre with a
numerical aperture of
less than 0.22 are now
available from DILAS.
Allowing clad-free coupling of the diode light
at wavelengths of 808, 915, 940 and 980 nm,
the 4- and 6-bar designs are based on industry-
standard single conduction-cooled bars, which
are optically stacked and polarization coupled.
Standard industrial-grade water chillers can cool
the module and its fi bre connector, which keeps
costs low. Optional features include an integrated
pilot beam, power sensor, fi bre interlock and user-
exchangeable protection window.
www.dilas.com
Ultrashort pulse oscillatorCoherent
The Mantis from
Coherent generates
over 300 mW of average
power at a nominal
centre wavelength
of 800 nm and has a
bandwidth over 70 nm, which can be compressed
to less than 20 fs using an optional external
Compact Pulse Compressor.
The product also incorporates a 5 W green
pump laser based on monolithic optically pumped
semiconductor laser technology, rather than a
traditional DPSS pump. A major application for
the Mantis is seeding short pulse amplifi er/OPA
systems to generate tunable high-energy, sub-
35 fs pulses for a wide range of pulse-probe
experiments in physics and chemistry.
www.coherent.com
Rotary stageAerotech
Aerotech has released a
low-profi le, high-speed
rotary stage that is
said to offer a compact
alternative to traditional
positioning spindles.
Capable of a top speed of 2500 rpm and with a
fundamental angular resolution of 3.6 arcsec,
the ADRH 100 features backlash and cog-free,
direct-drive servo motor technology with a directly
coupled precision encoder for excellent servo
bandwidth and maximum stiffness.
With synchronous error motions of 2 μm,
asynchronous error motions of 4 μm and a tilt
error of 15 arcsec, the ADRH 100 has an overall
height of around 55 mm and a tabletop diameter
of less than 105 mm. The ADRH 100 is also
available in custom-modifi ed OEM versions where
further space saving may be made by adapting
cable management, mounting confi guration or
other characteristics.
www.aerotech.com
DPSS laserCVI Melles GriotThe 85-YBB series compact yellow solid-state
laser head from CVI Melles Griot is ideally suited
for Rhodamine, ROX and Alexa Fluor dyes and
as a drop-in replacement for krypton-argon and
many green wavelength lasers. Offered with the
new CLC compact and universal OEM controller
that also drives the mini CRH diode lasers with
the same common command sets, the products
provide up to 25 mW of output at 561 nm and are
targeted at fl ow cytometry, scanning, metrology
and spectroscopy applications.
www.cvimellesgriot.com
Femtosecond regenerative amplifi erHigh Q Laser
The ultra-compact
femtoREGEN UC from
High Q Laser is an all-
in-one femtosecond
regenerative amplifi er
with a footprint of 34 ×78 cm that delivers 2 W at
a repetition rate of 200 kHz and pulse durations of
350 fs. The product is based on ytterbium-doped
materials and the company’s intracavity chirped
pulse amplifi cation ensures the compact design.
The housing integrates all pump laser diode
modules, the seed oscillator and the amplifi er. One
single 19-inch unit hosts all of the electronics and
control functions to ensure turnkey operation and
easy integration for OEM customers.
www.highqlaser.at
Infrared light sourceMoritex
Moritex says that its
latest incandescent
infrared light source
offers a broad light
spectrum unachievable
with LEDs. Compact in
design, the
MHAB-100 IR provides a stable output (±1%)
over a lifespan of greater than 1000 h. According
to the company, the 100 W halogen light source
delivers high illuminance (up to 30 000 lx)
across the 1000–1800 nm spectral region
enabling the light to penetrate into or through
materials including Si, GaAs, LiNbO3 and LiaO3.
A MHAB Series IR light source may be manually
controlled or remotely operated by analogue
or digital signals. All of the new light sources
offer the operational fl exibility of universal input
voltage (100–240 V, 50/60 Hz).
www.moritex.com
PRODUCTS
OLE • March 20 08 • o p t i c s .o r g /o l e34
Diffuse refl ectance materialsLabsphere
With 96–98%
refl ectance, Labsphere
says that its Spectralon
and Spectrafl ect
materials provide the
highest level of uniform light integration for
maximum effi ciency in light collection tubes
and light guides used in medical-imaging
equipment. The near-Lambertian properties of
Spectralon and Spectrafl ect deliver a uniform
dispersion of light that reduces hotspots in
coated cavity applications. The company quotes
a high refl ectance over a broad spectral range
of 250 to 2500 nm. Inert, thermally stable and
UV-resistant, the fi rm says that these materials
ensure consistent optical stability and long-term
performance reliability.
www.labsphere.com
Optical design softwareBreault Research OrganizationBreault Research Organization (BRO) has
released the next generation of its Advanced
Systems Analysis Program (ASAP). For the ASAP
2008 release, BRO’s development team has
focused on CAD interoperability, polarization
enhancements, optimization methods and the
ASAP HTML help system.
ASAP 2008 allows users to assign layers
and object names within SolidWorks prior to
analysis in ASAP. It also comes with numerous
polarization ray-tracing enhancements, including
a realistic polarization model and a Poincare
sphere visualization tool. Three new optimization
methods are included: a Brent’s method routine
for single-variable problems as well as downhill
simplex and simulated annealing methods for
multivariable problems.
www.breault.com
Deep-UV coatingAgilent
Agilent Technologies has
introduced proprietary
high-throughput UV
coatings that are said
to address the need
for highly accurate and
reliable beam delivery
in medical and semiconductor photolithography
systems. The coatings are claimed to increase
component lifetime while minimizing compaction,
thereby reducing the need for maintenance and
system down time.
www.agilent.com
Marking laserTrumpfTrumpf has introduced the TruMark 3020 marking
laser, claimed to be able to operate under
ambient temperatures of up to 4034 °C due to
its use of an air-cooling system rather than a
water-cooling system. A pilot laser and an optical
focus adjustment feature are available as options.
The laser weighs less than 10 kg even with these
extras. Scanner, laser head and power-supply unit
with hybrid cable are connected via plugs to allow
easy integration, and the control system has eight
inputs/outputs for fast signals in the microsecond
range.
www.trumpf-laser.com
Bluetooth interfaceOphir-Spiricon
The Quasar wireless
Bluetooth interface
from Ophir-Spiricon
broadcasts laser meter
data to any PC or
laptop within 10 m. It is
available for most Ophir smart heads including
thermopile, photodiode and pyroelectric, and
comes in two options. Firstly, a table model that
connects to any Ophir smart head and broadcasts
to a PC, or secondly directly mounted on an
Ophir thermocouple head providing optimal
portability and eliminating all cables. An optional
antenna extends the wireless range to 60 m, and
a rechargeable NiMH battery provides more than
20 h of use.
www.ophir-spiricon.com
Temperature-independent lasersSnake Creek LasersSnake Creek Lasers has developed a new
technology that allows solid-state lasers to
operate over a broad operating temperature
range while maintaining constant laser output.
The MiniGreen ETR (Extended Temperature
Range) is a DPSS laser packaged in a standard
semiconductor can for integration fl exibility,
reliability and high tolerance to G forces,
requirements typically found in portable and
outdoor applications.
www.snakecreeklasers.com
Laser modulesPacer
Pacer is now distributing
Alfalight’s AC3-808B
and AC3-808BW series
of high-brightness 30 W
808 nm fi bre-laser
pump sources that are
based on high-reliability single-emitter diodes.
The combined CPM III power modules include
a thermistor for temperature monitoring and
are available in standard BAL (808 ±3 nm) and
integrated Wavelength Stabilization Technology
(WST) (808 ±1.5 nm) versions. The modules are
claimed to provide over 20 000 h MTTF and do not
suffer the catastrophic failure mode inherent in
conventional bar-based emitters, say the company.
www.alfalight.com
PRODUCTS
OLE • March 20 08 • o p t i c s .o r g /o l e 35
Optical design softwareOptical Research Associates
CODE V 9.81 from
Optical Research
Associates streamlines
the fabrication of optical
systems by simplifying
the correlation of actual
test data and design parameters. For example,
new aspheric lens tolerancing capabilities can be
used with the CODE V Fast Wavefront Differential
Tolerancing feature to tolerance surface errors
that are easily measured in production using
surface profi lometry.
The software also addresses the demand
for ever-smaller features in the production
of semiconductor wafers. In particular, new
software functions provide direct information
about the critical dimension (CD) of the image.
These functions, which have been added to the
Partial Coherence analysis and TOR tolerancing
features, will help designers learn how small
variations in lens parameters affect the CD
variation across the chip.
www.opticalres.com
High-precision reference fl atsOptical Surfaces
Optical Surfaces says
that it can routinely
achieve a surface
accuracy of /20 p.v.
and a surface roughness
of 10 Å rms on reference
fl ats of up to 600 mm in diameter. Available in
high-stability materials such as glass, Zerodur
and silica, all reference fl ats come with full
quality-testing assurance. Optics of up to
450 mm in diameter are provided with a Fizeau
interferometric test report and larger fl ats are
quality assured using the Ritchey-Common test
procedure. The fi rm’s ISO 9001-2000-approved
manufacturing facility provides the resources to
supply from single specialist requirements to OEM
quantities in sizes from 105 to 600 mm.
www.optisurf.com
Active fi bresNufernThe NuPOWER line of active fi bres from Nufern
has been expanded to include new erbium/
ytterbium co-doped and ytterbium-doped large
mode area (LMA) fi bres. The new products
include the PM-EYDF-17/200 erbium/ytterbium
co-doped fi bre, and two ytterbium-doped LMA
fi bres designated PLMA-YDF-10/125 and PLMA-
YDF-25/400. All three fi bres are polarization-
maintaining (PM) double-clad fi bres and are
complemented by the availability of matched
passive fi bres for component and pigtail
development. The range also includes a non-PM
variant, LMA-YDF-10/130.
www.nufern.com
OLE • March 20 08 • o p t i c s .o r g /o l e
PRODUCTS
36
LASER ENGINEThe iFLEX-viperTM is a reliable and robust laser engine for use in biomedical instruments and semiconductor metrology applications. Up to 5 laser lines are delivered simultaneously via a rugged singlemode laser beam delivery system.
Wavelengths from 405, 445, 473, 488, 532, 561 and 640nm as standard.
www.point-source.com/ole
QCW stacked laser arraysIntense
The Hermes range
of high-power quasi-
continuous-wave
arrays from Intense
has been expanded,
and the newest lasers
are qualifi ed to military
standards. Hermes arrays are available as
vertically or horizontally stacked assemblies of
up to 10 bars, with lensed or unlensed options.
Standard confi gurations range from the Hermes
360 W 4-bar stacked array to the Hermes 900 W
10-bar stacked array, at a standard wavelength of
808 nm. Other wavelengths are available.
www.intenseco.com
Dynamic interferometer4D Technology
The FizCam 3000 from
4D Technology is a
Fizeau interferometer
for metrology of large
optical elements,
especially those requiring long measurement
paths. It utilizes dynamic interferometry to
acquire all measurement data in less than
1 ms, making it insensitive to vibration and air
turbulence. The system’s completely on-axis
design eliminates the inherent aberrations,
software corrections and alignment claimed to
be typical of tilted beam Fizeau systems. It is a
turnkey instrument including wavefront analysis
software and a complete high-speed computer
system, and offers true 4× motorized optical
zoom imaging along with remote control of focus
and zoom.
www.4DTechnology.com
Ultrafast laserLaser Support Services
The new continuous-
wave and pulsed
(including femtosecond
option) laser Chatarra
from Del Mar Photonics is available from Laser
Support Services in two all-solid-state options:
diode pumped or 1.9 μm thulium fi bre laser
pumped. A mid-infrared laser based on Cr2+
doped into ZnSE and broadly tunable around
2.5 μm, and is available with fi xed frequency,
narrow tunable or widely tunable options. The
laser is tunable over 600 nm from 2.2 to 2.8 μm
and delivers up to 6 W of output radiation.
www.laser-support.co.uk
Q-switchGooch & HousegoGooch & Housego has combined the corrosion-
resistant properties of stainless steel with the
power handling of aluminium to create a Q-switch
that can be cooled with ordinary water and still
deliver optimum performance. The company calls
this the Stallion manufacturing technique.
“This is a truly signifi cant breakthrough,” said
the company’s acousto-optics product manager,
Rob Swain. “The Stallion technique enables us to
deliver a Q-switch that can extend the lifetime of
products, reduce production downtime and cut
engineer costs without compromising performance.
It’s a cost-effective approach that enables us to
build a corrosion-resistant Q-switch and sell it at
the same price point as previous models.”
www.goochandhousego.com
Large-area silicon photomultiplierSensL
SensL says that its
SPMPlus is the fi rst
solid-state alternative to
an analogue large-area
photomultiplier tube.
The device comprises a
tiled array of individual
silicon photomultipliers (SPMs) and a connector
that allows all of the signals to be summed as a
single output.
The fi rst version has a total active area of
1.3 ×1.3 cm although this can be altered to
suit customer requirements. SensL says that its
patented biasing circuitry ensures that these
large-area SPMs retain a fast on-set time of
less than 10 ns and a recovery time of less
than 60 ns. Specifi cations state a high gain
of 106, and the module can be supplied with
appropriate interface/preamplifi er electronics
and a power supply.
www.sensl.com
Pulsed fi bre lasersAculight
The Telesto family
of high-peak-power,
polarized, 1 μm pulsed
fi bre lasers is now
available from Aculight.
Applications range from surveillance and LADAR to
nonlinear conversion. Aculight’s standard Telesto
laser, the P36L-1064, produces 3 to 5 ns pulses
at repetition rates from 20–750 kHz with 4 W of
average power (>50 kHz). Maximum pulse energy
is specifi ed as 80 μJ and peak power is 25 kW. The
fi rm quotes that the unit’s 1 μm output is less than
1.5 times the diffraction limit. Telesto P36L-1064
measures just 2.6 ×6 ×7 inches and weighs less
than 8 lb. Custom confi gurations are also available.
www.aculight.com
Coherence controlToptica PhotonicsToptica Photonics says that the coherence length
and linewidth of tunable diode lasers can be
varied over more than nine orders of magnitude
(from sub-Hertz levels into gigahertz ranges)
using its new FALC 110 and LCC. The Fast Analog
OLE • March 20 08 • o p t i c s .o r g /o l e
PRODUCTS
37
+32(0)14 570 670
+45 46 55 99 99
+33(0)1 60 79 59 00
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+ 39 02 535 831
+34 91 453 11 60
+31(0)172 44 60 60
+44(0)1908 326 326
+49 18 56 58 30
Laser Beam Analysis > Laser Power & Energy Meter> Beam Profile, M2
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Spectroscopy> Module & Systems from UV to IR> CCD Spectrometer> Raman, LIBS & Fluorescence
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Wavefront Analysis> Shack-Hartmann Analyzer> Deformable Mirror
BFi OPTiLAS European Offices :
Instrumentation
www.bfiopt
ilas.c
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Photonics for Europe
Linewidth Control module (FALC 110) is a high-
bandwidth regulator for laser linewidth reduction
and fast frequency locking. The Laser Coherence
Control (LCC) unit, by contrast, provides a
modulation source to broaden the laser linewidth
up to gigahertz ranges, maintaining single-line
emission and spectral control. A reduction in
linewidth is benefi cial for applications such as
precision spectroscopy, whereas increasing the
spectral line in a well-controlled way can match
a laser’s emission to a Doppler-broadened
absorption profi le of a gas, for example.
www.toptica.com
Nanosecond oscillatorAdvanced Optical TechnologyAdvanced Optical Technology (AOT) has extended
its range of short pulse (~1 ns) solid-state TEM00
oscillators. The new product is called the
AOT-YAG-10QE and is an electro-optically
Q-switched oscillator that offers pulse energies
in excess of 150 μJ at kilohertz rates.
AOT is targeting this product at laser
applications that do not require the highest
repetition rates but benefi t from higher pulse
energy and peak power. The new oscillator can
be used with the company’s standard harmonic
modules and achieves conversions of >40% to
532 nm, >30% to 355 nm and >20% to 266 nm.
www.AOTlasers.com
CCD cameraSVS-VISTEKThe SVS274 from SVS-VISTEK is the latest
addition to the company’s line of SVCAM
cameras. The product runs at 24 frames per
second at a full resolution of 1620 ×1220
although higher rates can be achieved in partial-
scan mode. Based on Sony’s 1/1.8 inch sensor,
there is also the option of reading a half or a
quarter of the entire number of lines (known
as decimation), while the fi eld of view remains
unchanged. This also results in a higher frame
rate. The camera is available with a CameraLink
or a Gigabit Ethernet interface as well as in a
monochrome or a colour version.
www.svs-vistek.com
DLP pico-projector chipsetTexas Instruments
DLP Technology from
Texas Instruments
has announced the
production availability
of a DLP Pico chipset.
The product will consist
of the DLP Pico chip and the DLP Pico processor
(DDP1500 and DDP1505). The DPP1500 is
targeted at embedded applications for handheld
devices, while the DDP1505 will serve the
standalone handheld companion market.
According to Texas, the DLP Pico will deliver
an aperture ratio of more than 92%, tens of
thousands of pixel elements, switching speeds
of less than 20 μs and DarkChip native contrast
ratio process technology. The chipset is also said
to display the widest colour gamuts possible with
the fl exibility to operate with the latest in LED
illumination technology.
www.dlp.com
ADVERTISERS’ INDE X
The index is provided as a service and, while every effort is made to ensure its accuracy, Optics &
Laser Europe accepts no liability for error.
Advanced Photonix Inc www.advancedphotonix.com 9Avantes BV www.avantes.com 31B&W Tek Inc www.bwtek.com 7Basler Vision Technologies www.basler-vc.com 28Cambridge Optical Sciences www.cos.co.uk 22CVI Melles Griot www.cvimellesgriot.com OBCDocter Optics www.docteroptics.com 11EdgeWave GmbH www.edge-wave.com 30ELCAN Optical Technologies www.elcan.com IBCESCO Products www.escoproducts.com 11Financiere BFI Optilas S.A.S www.bfi optilas.com 30, 37Gentec Electro-Optics Inc www.gentec-eo.com 6GWU Lasertechnik Vertriebs GmbH www.gwu-group.de 22Koheras A/S www.koheras.com 4Laser Components (UK) Ltd www.lasercomponents.co.uk 27
Laser Micromachining Limited www.lasermicromachining.com 11Leister Process Technologies www.leister.com 33M u t AG www.mut-gmbh.de 10New Focus Inc www.newfocus.com 14Ocean Optics www.oceanoptics.com 8Ophir Optronics Ltd www.ophir-spiricon.com IFCOptec Berlin-Brandenburg eV www.optecbb.de 11Optical Society of America www.osa.org 26Optigrate www.optigrate.com 35Optima Research Ltd www.optima-research.com 29PCO www.pco.de 35 Photeon Technologies GmbH www.photeon.com 12Photon Inc www.photon-inc.com 31Point Source Ltd www.point-source.com 36Quantel www.quantel-laser.com 34RSoft Design Group Inc www.rsoftdesign.com 18SIOS Mebtechnik GmbH www.sios.de 7Thorlabs GmbH www.thorlabs.com 13
38 OLE • March 20 08 • o p t i c s .o r g /o l e
BACK CHATICFO sees rapid expansion of
Spain’s photonics industry
Having launched in March 2002, the Institute of Photonic Sciences (ICFO) in Barcelona, Spain, will soon house more than 300 researchers in 45 fully equipped laborat ories over an area of some 9000 m2.As well as providing a hub for research and education into both basic and applied optics, ICFO has an eye on economic devel-opment. The person in charge of promoting this activity is Silvia Carrasco, ICFO’s direc-tor of knowledge and technology transfer.
What are the key missions of ICFO?ICFO’s mission is three-fold: frontier research, education at the postgraduate level and technology transfer. In research, we are conducting cutting-edge studies into several areas of photonics. In edu-cation, our PhD degrees are focused on photonics and attract top international students. In economic development, we are pro-active in establishing partnerships with industrial corporations.
ICFOnians moved into a dedicated build-ing in the winter of 2005 and we are in a privileged position: the Mediterranean Technology Park in Barcelona’s metro-politan area. We believe that the balance of having all three activities under one roof is what provides the best scenario for our PhD students to grow, and for com-panies and partners to get the best from us. ICFO’s expansion will allow us to reach the critical mass needed to meet our mis-sion optimally, especially in relation to industrial partnerships.
What are ICFO’s core competencies?At ICFO we understand light as a tool: an important enabling tool for today and an even more important tool for tomorrow. We conduct wide-ranging research into many areas of photonics, but have a special focus on quantum information technol ogies, nanophotonic devices, optical sensors, ultrafast optics, optoelectronics, integrated optics and biophotonics/biomedical optics.
We plan to broaden and complete our scope with a few new areas. In partic ular, we will reinforce the existing areas by add-ing facilities. One of the areas that will expand signifi cantly is biophotonics, with
the launch of a unit dedicated to biomedical optics, partially endowed by a substantial donation from the Cellex Foundation.
What does your role involve?My role is to facilitate the relationships between ICFOnians and all types of indus-tries and corporations. My job is to create opportunities. This could be opportun ities that connect ICFOnians with external partners, opportunities that develop our technological portfolio or opportunities that allow us to fulfi l the business needs of our industrial allies. My role is devoted to building mutual knowledge and trust between ICFO and all types of industrial colleagues and partners.
Can you give me some examples of ICFO’s commercial activities?We are particularly active in patenting different types of optical sensors and our patent portfolio includes innovations in microscopy, plasmonics and sensors for hostile environments, to name a few. We are currently negotiating a licence agree-ment for a uniquely robust fi bre-optic sen-sor that our researchers invented.
Radiantis, a company that spun-out of ICFO a couple of years ago, is commer-cializing optical parametric oscillators and frequency-conversion devices. The systems offered by Radiantis address dif-fi cult spectral regions from the ultraviolet to the mid-infrared and cover continuous-wave to ultrafast femtosecond temporal domains. The Radiantis team is led by ICFO’s Prof. Majid Ebrahim-Zadeh.
What is ICFO’s Corporate Liaison Program?One key aspect of my role is to build trust between the ICFO and local and interna-tional corporations with whom we may team up to co-develop technology. Here, the expertise of our senior researchers and PhD students becomes a unique asset.
Our Corporate Liaison Program is the instrument that we use to establish this ini-tial connection. We do not limit ourselves to a specifi c model for technology transfer. Our aim with companies is to achieve com-mon goals, so we have to be fl exible. We set a customized action plan with each mem-ber of the program to maximize mutual benefi ts. ICFO is an outstanding partner through which to establish collaborations with Spanish photonics companies.
What is your view of the photonics industry in Spain?Several industrial sectors related to pho-tonics are growing in Spain. One exam-ple is biotechnology, a market where the regional government is focusing resources and initiatives in the Barcelona metropol-itan area. Another example is clean tech-nologies, including solar. Spain’s potential in this area is enormous, as is refl ected by the current investments.
The number of photonics companies based in Spain is rising, especially spin-offs and medium-sized enterprises. An example of a medium-size company is Monocrom, which specializes in custom laser systems. There are also large corporations, like Isofoton, a leader in the solar sector. Sev-eral companies are opening new premises in Spain such as French-headquartered Imagine Optic, a leading supplier of Shack-Hartmann wavefront technology.
Research in photonics in Spain is growing in different parts of the country, in partic-ular in groups located in Barcelona, Madrid, Valencia, Zaragoza and Cantabria. Our col-leagues in Madrid and Valencia have world-class capabilities in silicon photonics. The government has also recently announced a new laser centre in Salamanca, which will specialize in ultra-intense lasers and their industrial applications.
The Institute of Photonic Sciences in Barcelona is undergoing a signifi cant expansion. Silvia Carrasco tells OLE what ICFO can offer companies and gives a snapshot of Spain’s thriving photonics industry.
Barcelona’s ICFO will soon house 300 researchers.
ICFO
N O R T H A M E R I C A • P R E C I S I O N O P T I C S A N D E L E C T R O N I C S • E U R O P E
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