spectraphysics sp-164, sp-165 & sp-168 service manual

7/27/2019 SpectraPhysics SP-164, SP-165 & SP-168 Service Manual

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Spectra-Physics

Model 168 and 1688OEM and Scientificlon Lasers

Instruction ManualLASER PRODUCTS DIVISION

1250 W Middlefield Road, Mountain VIew, CA 94039-7 013Slemensstrasse 20, D-6100 Darmstadt-Kranlchsteln, West Germany

Part Number 230000- 076A


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I


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PREFACE

This manual contains Information needed for day-to-day operat ion and maintenance of a l l versions of theModel 168 OEH and S c l e n ~ l f l c lon Laser. Including the Model 1686. You wll I f ind Instruct ions for Ins ta l -la t ion, operation, routine maintenance, and such t roubleshoot ing as can be done without removing th e coversof the Model 265 Power Supply.

Model 168 ton lasers ar e sold only on an OEM or export basts. Versions other than Model 1686 do not complywith CDRH Performance Standard 21 CFR 1040 10(dl; It Is the user 's responsibi l i ty to cer t i fy compliance ofhis product where appl icable.

I v


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TABLE OF CONTENTSINTRODUCTION

EMISS ION AND ABSORPT ION OF L IGHT 1- 1POPULATI ON INVERS ION l - 2ARGON AS AN EXC I TATI ON MEDI UM 1-3THE RESONANT ~ T I C A L CAV I TY 1- 5THE PLASMA TUBE 1-5THE ~ D E 168 I ON LASER SYSTEM 1- 5THE LASER HEAD 1-6THE rvr>DE L 26 5 PO WR SU PPLY 1- 7SPECIFICAT IONS 1-8

LASER SAFETYPRECAUT IONS FOR TH E SAFE OPER ATION OF CLA SS IV -HI GH POWE R LASERS 2-1SCHEDU LE OF MA INTEN ANCE NECESS ARY TO KEE P MODE L 1686 LA SERS IN CO MPLIANCEWI TH CDRH 21 CFR CH APTER 1, SUBC HAPTER J, PAR TS 1040 .1 0 AND 1040 .11 2-2COVER INTERLOCKS 2-2BENJl BLOCKER 2-2

INSTALLATIONUNPACKING YOUR LAS ER 3- 1ELECTRICAL OONNECT IONS 3- 1WATER CONNEC TI ON $ 3-1

OPERATIONPOWER SUPPLY CONTRO LS 4-1LASER HEAD {))NTRO LS 4- 3TEST I NG 4-4WATER TESTING THE PLA SMA TU BE 4-4CONTROL OPERAT ION TESTS 4-4START ING THE ARGON LASER 4-6ADJ USTMENT FOR PEAK OUTPUT PO WE R 4- 6WAVELENGTH SE LEC TI ON 4-7FINDING PEAK OUTPUT WTH THE FIELD CON TR OL 4-7GAS FILL 4-7CHANG ING OPT IC$ 4- 7SHUTDO WN PROCE DUR E 4- 8

HA INTENANCENOTES ON TH E CLEANI NG OF LA SE R OPTI CS S-2CLEAN ING PR ISMS ~ D MIRRORS 5-2CLE ANING PLASMA TU BE WIN DOWS S- 3AL IGN I \K3 THE MIRRO RS 5- 4AL IGN ING THE PLASMA TUB E 5-5AL IGNING THE PRISM 5- 6REPLA CEMENT PARTS S- 8

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TABLE OF CONTENTS (con't .l

TROUBLESOOOT INGSYMPTOM:SY t-1PTOM: CIRCUIT BREAKER WON'T TURN ON5-10CIRCUIT BREAKER TRIPS OFF5-10SYMPTOM: PLASMA TUBE FAILS TO IGNITE 5-10SYMPTOM: LOW OUTPUT POWER. . . . 5-11SYMPTOM: CURRENT CANNONT BE RAISED TO MAXIMUM5-12

Y r v t = > T O ~ ~ : NO CURRENT 5-12SYMPTOf4: NO OUTPUT BEAM, PLASMA TUBE GLOWS INDICATING DISCHARGE 5-12

KRYPTON LASER


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LIST OF FIGURES (oon 1 1". >

FIGURE PAGE4.24.34. 44. 54. 64.75.15. 25. 35.45.55. 65.75.85. 95.105. 11

Front Pane I f'.1eter. . 4-1Maximum Aval lable Current for Model 168 Verslons4-2Rear f ~ l r r o r AdJustments .4-3Anode End Water Connecttons4-4Power Supply Control Operations Tests 4-5lon Laser Opt1cs Optlons 4-9Schematic Representation of Ideal Resonator Allgnment5-1Cleaning the Mrror Surface 5- 2Lens Tissue Folded fo r Prism Cleanlng S-3Msaligned Mirrors Cause Lasing at Reduced Power5-5Misaligned Plasma Tube Causes Lasing at Reduced Power 5-5Prism Alignment Adjustment c r e ~ s 5 - 6P lasma Tube Alignment Adjustments5- 7Vertical Search 5-12Schematic, Automatic Pressure Control Circui t - Model 168-01, -315-13Schematic, Model 265 Proteus Flow Switch Clrcult5-14r.4o del 265 Sche matic 5-15

6 .1 Gas Fi l l Indicator 6-2

Sl ~ I T S

The fo ll owin g System lnte rnatlon a I CSI) units, abbreviations, and prefIxes are used In Spectra-Physi csma nual s :Quant i tyma ssle ngt ht imef re quencyforcee ne r gypow ere lec t r ic currente lectrlc chargee lectric potentialre s IstanceInductancema gnetic fluxmag netic flux densityluminous Intensityt empe r ature

Unitk llo grammetersecondhertznewtonjoul ewattamperecoulombvoltohmhenryweberteslacandelakelvin

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Abbreviation Prefixeskg tera ( 1012) Tm glga ( 109) Gs mega ( 1o 6> MHz kilo ( to3) kN decl ( 10-1> dJ cent I ( 10-2) cw mill I (10-3> mA micro uo-6> f.lc nano ( 10-9> nv plco uo-12> p0 atto ( 10-18) aHWbTcdK


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INTRODUCTIO,.

z

z

X

Figure 1.1: Elecrrons occupy disTincT orbi-tals fflaT are defined by the probabi l iTy of f inding an elecrronaT a given posiTion. ffle shape of ffle orbi-tal being de1erlned by ffle radial and angulardependence of th e probabl I 11-y.

EMISSION NJ ABSORPTION Of LIGHTlaser Is an acronym derIved from " I I ght amp I I f I cat ion by stimulated emission of rad ia t ion . " Thermal- -radiators, such as the sun, scatter l i gh t In a l ldirect ions, the Individual photons having no def i nite relationship with one another. But becauseth e laser Is an osci l la t ing ampl i f ier of l ight ,and because I ts output comprIses photons that areIdent ical In phase, direct ion, and amplitude, ItIs unique among l igh t sources. Its output beam Issingular ly direct ional , Intense, monochromatic,and coherent.Radiant emission and absorption take place withinthe atomic or molecular structure of materials.The contemporary model of atomic structure de scribes an elect r ical ly neutral system composed ofa nucleus with one or more electrons bound to f t .Each electron occupies a d is t inc t orbi ta l tha trepresents th e probabl I t ty of f inding the electronat a given posit ion re lat ive to the nucleus. Eachorbi ta l has a character ist ic shape that Is defined*"Light" wi l l be used to describe the portion of

th e electromagnetic spectrum from far Infrared toul t rav io let .

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by the radla I and angular dependence of that probab i l i ty , e.g. , a ll "s" orbi ta ls are spher ical lysymmetrical, and a ll "p " orbi ta ls surround the x ,y, and z axes of the nucleus In a double-lobedconf igurat ion (see Figure 1.1>. The energy of anelectron Is determined by the orbi ta l tha t It occupies, and the overal l energy of an a tom- I tsenergy level - depends on the distr ibut ion of I tselectrons throughout the available orb i ta ls . Eachatom has an array of energy levels: the level withthe lowest possible energy Is called the groundstate, and higher energy levels ar e exci tedstates. I f an atom Is In I ts ground state, Itwil l stay there unt i l It Is excited by externa Iforces.l-1ovement from one energy level to another (a t ransi t ion) happens when th e atom ei ther absorbs oremits energy. Upward transit ions can be caused bycol l is ion with a free electron or an excited atom,and t ransi t ions In both directions occur as a re su It of Interact l on wIth a photon of I I ght. Consider a t ransi t ion from a lower level whose energycontent Is E1 to a higher one with energy E2 Itwil l only occur I f the energy of the Incident photon matches the energy difference between levels,I .e.,


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11 Iwhere h Is Planck's constant, and v Is the f re-quency of the photon.Likewise, when an atom excited to E2 decays to E1,It loses energy equal to E2-E1 Because I ts tendency Is toward the lower energy state, the atommay decay spontaneously, emitt ing a photon withenergy hv and frequency

121Spontaneous decay can also occur without emissionof a photon, the lost energy taking another form,e.g. , t ransfer of kinet ic energy by co l I Iston withanother atom. An atom excited to E2 can also bestimulated to decay to E1 by Interact ing with aphoton of frequency v , shedding energy In the formof a pair of photons that ar e Ident ical to the In c ident one In phase, frequency, and direct ion. Bycontrast, spontaneous emission produces photonsthat have no direct ional or phase relat ionshipwIth one another.A laser Is designed to take advantage of absorpt ion, and both spontaneous and stimulated emissionphenomena, using them to create condit ions favorable to l igh t ampl i f icat ion. The fol lowing paragraphs describe these condit ions.

POPUU\T ION INYERS ION

The absorption coef f ic ient at a given frequency Isthe dif ference between the rates of emission andabsorption at that frequency. I t can be shownthat the rate of excitation from E1 to E2 Is proport on a I to both the number of atoms In the I owerlevel CN1 l and the t ransi t ion probabi l i ty . Simil ady , the rate of stimulated emission Is proport ional to the population of the upper level CN2>and the t ransi t ion probabi l i ty . Moreover, thet ransi t ion probabi l i ty depends on the f lux of theInc ident wave and a character ist ic of thet lon ca l ied I ts "cross sect ion." It canshown that the t ransi t ion cross section

t ransl-a I so beIs the

same regardless of direct ion. Therefore, the ab sorption coef f ic ient depends only on the d i f fe r -ence between the populations lnvol ved, N1 and N2,and the f lux of the Inc ident wave.When a material Is at thermal equi l ibr ium, aBoltzmann distr ibut ion of I ts atoms over the array

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of avai lable energy levels exists with nearly a llatoms In the ground state. Since the rate of absorption of a ll frequencies exceeds that of emission, the absorption coef f ic ient at any frequencyIs posi t ive.

I t enough l ight of frequency v Is supplied, thepopulations can be shi f ted unt i l N2=N1 Underthese condit ions the rates of absorption and st imulated emission are equal, and the absorption coef f i c ien t at frequency v Is zero. I f the t ransi -t ion scheme Is l imited to two energy levels , It IsImpossible to dr ive the populations Involved be yond equal i ty ; that Is , N2 can never exceed N1 be-cause every upward t ransi t ion Is matched by one Inthe opposite direct ion.However, I f three or more energy levels are em-ployed, and I f thei r relat ionship sat ls l t les car-taln requirements described below,citat ion can create a populationwhIch N2>N1

addlt lona I exInversion, In

A model four-level laser t ransi t ion scheme Is depleted In Figure 1.2(a). A photon of frequencyv 1 exci tes or "pumps" an atom from E1 to E4 I fthe E4 to E3 t ransi t ion probabi l i ty Is greaterthan that of E4 to E1, and I f E4 Is unstable, theatom wi l l decay almost Immediately to E3 I fatoms that occupy E3 have a re lat ively long l i f e -t ime, the population wl I I grow rapidly as excitedatoms cascade from above. The E3 atom wi l l eventual ly decay to E2, emitt ing a photon of frequencyv2 Final ly , I f E2 Is unstable, I ts atoms wil lrapidly return to the ground state, El' keepingthe population of E2 small and reducing the rateof absorption of v 2 In this way the populationof E3 Is kept large and that of E2 remains low,thus estab l lshlng a popu lat lon lnvers !on betweenE3 and E2 Under these condit ions, the absorptioncoeff I clent a t v2 becomes negatl ve. Ll gh t Is am-p l i f i ed as It passes through the material , whichIs now cal led an "act ive medium." The greater thepopulation Inversion, the greater the gain.A four- Ieve I scheme, I I ke that descrIbed above,has a d is t inc t advantage over three- level systems,In which E1 Is both the or! gi n of the pumpingt ransi t ion and the terminus of the losing t ronsl-t l on . In the four-level arrangement, the f i r s tatom that Is pumped contributes to the popu lat lonInversion, while over ha I f of the atoms must bepumped from E1 before an Inversion Is establishedIn the three- level system.


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/ // // // /E3 4p

Visible Laser TransitionPumping Transition

E2 4s' ' ' 'E, 3sf AtIonizing Transition

~ - - - - - - ~ ~ ~ ~ - - A r...., ground(a) (b )

Figure 1.2: A ~ y p l c a l four-level laser ~ a n s l ~ l o n scheme (a ) compared to t h a ~ of visible argon (b).One collision Ionizes n e u ~ a l argon. and a second pu1111ps th e lon 1o an excl1ed sta1e.

In commercIa I Iase r desIgns itte source of exc I ta t lon energy Is usually optical or e lec t r ica l . Arclamps are often employed to pump sol id-statelasers. The output of one laser can be used topump another, e . g ., a l iquid dye laser Is oftenpumped by an lon laser . An electr ic discharge Isgenera l ly used to excite gasseous media l ike argonor krypton.ARGON AS HI EXCITATION M::DIUMThe propert ies of argon ar e probably the best un derstood of a ll th e Ionized gas laser media; I tst ransi t ion scheme Is compared to the model InFigure 1 . ~ ( b ) , and I ts vis ib le energy level diagram Is depleted In Figure 1.3. The neutral atomIs pumped to th e 4p energy level - the or ig in ofthe lasing t ransi t ion - by two col i Is Ions withelectrons. The f i r s t Ionizes the atom, and th esecond exci tes the lon from I ts ground state


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--.,..--- 112 4p 2s0

4s 2p { 1/23 / 2 - - - ~

3/2 } 4p 2p 01/2} 4p 2oo

1/213/2 4 04p D5/25/7

Figure 1.3: Energy levels of tf1e 4p - 4s argon lon laser 1ransl"tlons

Ton lasers Is not necessarily advantageous, exceptIn single- l ine appl icat ions.

Most of the vis ib le laser t ransi t ions In a cont inuous wave argon Ion laser have approximate I y th esame power-to-gain rat io as the 488 nm l ine, a lthough they are weaker than that l ine and haveless gain. The 514.5 nm l ine, however, Is an exception. Whl le I ts gain Is only about 1/4 that ofthe 488 nm l ine, I ts output Is approximately 25%greater, provided th e gain Is suf f ic ient to overcome I nterna I I osses. The upper state of the514.5 nm l ine Is In a dl f ferent tam I I y of Ieve Isthan that of most of the other t ransi t ions and th edifference In atomic constants changes th e powerto-gaIn ra t Io .The relat ionship of !on laser gain to Input powerIs quite di f ferent from that of other lasers. Theexci tat ion process that produces th e populat ionInversion requires more than one co l I Is ton toreach the upper state of th e t ransi t ion and thegain varies approximately as the square of thecurrent density . The close relat ionship betweencurrent density and Input power density suggeststhat high Input power densit ies ar e desirable fo rmaximum output power. The output power, In tact ,

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varies approximately as th e square of the Inputpower over a large range of operat ing parameters.

A magnetic f ie ld , Induced by a solenoid surroundIng th e plasma tube, tends to force electronsaway from the tube wa I Is . Since they are notlost , th e electrons are subjected to th e plasmadischarge and the energy distr ibut ion of th e treeelectron population r i ses. Since the upper energylevels can only be populated through col l is ionsbetween Ions and free electrons having at leastthe energy of the state beIng excl ted, the presence of th e magnetic f ie ld enhances the populationInversion.

The magnetic f ie ld also causes Zeeman spl i t t ing ofthe laser l ines. These sp l i t l ines have e l l l p t l ca I po I ar I zat l on . S nee the pI asma tube wIndowswi l l only t ransmit ver t ical ly polar ized l ines, theenergy of th e sp l i t l ines Is lost .Output power, Increased by an enhanced populat ionInversion and decreased by the Zeeman ef fect , de pends direct ly on the strength of th e magneticf ie ld . There Is an optimum f ie ld strength to reach I lne.


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TifE RESONANT


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Industr ia l spectroscopy, data recording and re t r ieva l , biological cel l sortl 'ng, re t ina l surgery,and endoscopic coagulat ion.o Argon lasers are aval lable In four baste ver

sions, broad band or single l ine, TEMoo ormult i mode.

0 Krypton lasers ar e avai lable In four basteversions: standard or automatic pump, TEMooor multlmode. The krypton lasers providebroad band output In the red wavelengths andmoderate power In the near Infrared.The Krypton Automatic Pressure Control PumpLaser Incorporates an automatic krypton pressure control pump and related elect ron ics .In addit ion to the standard krypton wavelengths, thIs mode I performs we I I In thepressure-sans I tl ve green-ye I low region of thespectrum.

Refer todescription

Output Power Specif icat ionsof th e avai lable models

fo r aand th e

versIon numbers.The laser system Is composed of th e Model 168Laser Head and th e Mode I 265 Power Supp I y. Thelaser head contains th e resonator with laseropt ics , plasma tube, and magnet. The power supplycontains a ll of the electronic c i rcu i ts necessaryto create, sustain, and monitor the plasma tubedischarge; to monitor and control the outputpower; and to supply and regulate th e magneticf le I d.

THE LASER IAD

Resonator

A massive extruded aluminum resonator providessupport for th e plasma tube, opt ics, and magnet.The excel lent thermal conduct iv i ty of aluminumassures uniform dis t r ibu t ion of heat throughoutthe structure, keeping thermal gradients to a minImum. As the temperature of th e un i t changes, I tsdimensions change uniformly, thereby maintainingalignment and beam-pointing s tab i l i t y . The aluminum mirror mounts are held against th e resonatorwith s t i f f springs. The mass of the mounts andresonator, combined with th e st i f fness of th esprings, reduce mechanical vibrat ions of th emirrors, thereby reducing frequency J i t te r .

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A set of optics for ei ther s ingle- l ine or a l l l ines operation Is suppl ied with each laser. Theoptics ar e held In threaded mounts tha t can bechanged. The output mirror holder Includes a beamsp l i t te r fo r th e bu i l t - In power meter and l igh ts tab i l i zer . AI 1- l lnes operation Is obtained usinga high ref lector . An assembly containing a Brewster-angle prism and high re f lec tor Is employedfo r single- l ine operation.

f ~ o d e l 1688 lasers employ a f ixed aperture, locatedInside th e cavi ty near the output coupler, toproduce a TEM00 output beam.Plas1111 Tube

All Model 168 Lasers use rugged BeO and glassplasma tubes bu i l t with hard-seal technology forlong l i fe and high r e l i ab i l i t y . The gas returnpath Is a separate, large-bore tube that al lowsadequate gas conductance wh l ie prevent! ng tubefa I I ure due to an arc dl scharge through the returnl ine . The high thermal conductiv i ty, strength,and mechanlc11l s tab i l i t y of BeO make It an Idealmaterial for plasma tube construct ion. I ts resistance to erosion, caused by borrbardment by thehigh energy plasma, assures long tube l i f e . Thebore segments 11re Joined by a proprietary, nonmetal l ic bonding process. The fused-si l ica windows ar e hard-sea led to th e tube at Brewster 1 sangle, thereby allowing a thorough, hlgh-temperllture bakeout of the ent i re tube during processing.The resu l t Is a contamination-free tube with along l i fe expectancy.

Model 168 argon and krypton lasers use the highestgrade of opt ical fused quartz avai lable. Fusedquartz 1s th e material of choice for vis ib le operat ion because of I ts high pur i ty , uniform opt icaland mechanlca I propert ies, and ab i l i t y to be polIshed to a superb optical f in ish.All argon models employ a gas fill reservoir connected to the pI asma tube through a solenoIdactuated valve that Is control led by circui t rylocated within the power supply.Most krypton laser l ines are pressure sensi t ive.A combined pump and fill mechanism provides th eab i l i t y to raise and lower gas pressure on lasermodels 168-01,-31,-41,-71 The pump can be operatedautomatical ly, or It can be operated manually fo ropt mum performance a t a selected pressuresans I tl ve krypton I I ne .


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THE KX>EL 265 POWER SlFPLY

The tu I I y regu I a ed power supp I y contro Is the dIscharge current to provide consistent laser performance despite f luctuat ions In l ine voltage. Aseparate c i rcu i t provides current to the magnet.The magnetic f ie ld Is continuously adjustable a l-l owIng max Imum petormance at a I I Iaser I I nes.A I I ght stab Ill ze r c i rcu i t uses feedback from aphoto detector In the laser head to control outputpower by regulating plasma current. Current cana I so be contro l ied manua I I y from the f ront pane Iof the power supply.The photo detector sl gna I can a I so be fed to themulti-purpose meter on the f ront panel. The metercan monitor output power, plasma current, gaspressure, or the condit ion of the plasma currentregu I ator .An audible alarm warns of low gas pressure. A key

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switch activates the gas till ci rcui t , adjustingthe pressure to opt! mum performance Ieve Is . Thecl rc u It automat! ca I I y prevents overt Ill. When theautomatic pressure control system Is used with akrypton laser, spec I a I electronIcs monItor plasmatube pressure and automat! ca I I y control the pump/till system tor optimum performance.Option 411-813 adds electronics to the Model 265Power Supply that allows modulation and remotecontrol of the laser. The laser output can bemodulated at rates up to 10 Hz.Option 411-814 adds a c i rcu i t to the Model 265Power Supp I y that automat! ca II y starts the laser.The s tar t sequence Is In i t ia ted 30 sec after thecl rcu It breaker on the f ront pane I of the powersupply Is closed.The fol lowing tables provide detailed speci f icat ions for a l l of the aval lable Model 168 versions.


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SPECIFICATIONS

PHYSICAL

ELECTRICAL SERY ICE

WATER SERY ICE

PERFORMANCE

Dimensions

Shipping WeightCavity Length

TypeVoltage Requlred 1Current RequiredPower Required

Flow RatePressure

Stabili ty

Beam Dl ameter3Beam Divergence}Polar IzatlonMode Spacing

Specifications subject to change without notice.

Power Supply

Laser

w/o prismw/ prism

MinimumMinimumMaximumLight Control ModeCurrent Control ModeLight Control Mode{In any 30 min period,after 2 hr warmup)Current Control Mode{after 30 mIn warmup l

w/o prl smw/ prism

Versions 168-09 and -49 have a voltage regulation range of 208+8%-5% V {ac.l

42.5x27.7x41.9 em16.7x10.9x16.5 In14.9x14.4x100.1 em5.9x5.7x39.4 In105 kg, 232 lbs0.9 m0.95 m3-phase w/ earthground2088% v38A13.1 kW

8.5 1/mln,1.8 kg/cm2,3.5 kg/cm 2,0.2% rms1%

0.5%

1.25 mm0.69 mradVert Ica I167 MHz158 MHz

2.2 g/mln25 ps i50 ps i

2 Performance at 514.5 nm {argonl, at the specified power, 10 Hz-2 MHz. At 647.1 nm (krypton>, at thespecified power, 0.3% rms, 10 Hz-1 MHz. Contact Spectra-Physics for performance data a t otherwavelengths.3 For TEM 00 versions: a t 1/e2 points, data for 514.5 nm. Data for other wavelengths {assuming no change Inoptical configuration) Is given by:

D IA< 1 lDIAC2l

1-8


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OEM - 56Sc ie nt if i c -1 6

457. 9- 514. 5 nm 2W

OEM - 46Sc ie ntif i c - 06

to 9o . o2 nm 0. 02528 .7 2 0 .1 5514 . 5 0. 80501. 7 0.1 0496 . 5 0. 28488 . 0 0.7 0476 . 5 0. 25472 .7 0. 05465 . 8 0. 05457. 9 o . 11454. 52 3

OUTPUT POWER SPECIFICATIONSArgon lon Laser Power (W)

Br oad Ban dTEMoo

-57 -58 -5 9-17 -18 - 19

3W 4W 5W

SIn g Ie - Ll ne 1TEMoo

-4 7 - 48 - 49- 07 -08 -09

0.0 3 0. 04 0.050. 25 0. 30 0. 341. 20 1.70 2. 000. 20 0.3 0 0 .4 00.4 0 0. 60 0.701. oo 1. 30 1.500.3 5 0. 60 0.750.13 0. 25 0.300. 07 0.1 3 0. 200. 20 0.30 0. 350.05 0 .10 0.12

Krypton lon Laser Power (W)Broad Band

TEMoo

Multi mode-67 - 68 -69-27 -2 8 -293W 4W 5W

Multimode-7 7 -78 -79-37 -38 -39

0.03 0.04 0.050.25 0.30 0.341 .20 1. 70 2.000.20 0.30 0.400.40 0.60 0.701.00 1. 30 1. 500.35 0. 60 0.750 .13 0.25 0.300.07 0.13 0.200.20 0.30 0.350.05 0.10 0.12

MultimodeStandard Pump Version Standard Pump Version

OE M -61 -41 -51 -71Scientific -21 -01 -11 -31

752.5-799 .32 nm 0.25 0. 25 3 3647.1-676 .4 0.60 0.60 o.ao 0.80

Spec i fications subject to change without notice.Sln gle -llne powe rs for argon lase rs ar e specified at 514.5 nm and 488.0 nm only. Other powers Indicatedare nominal; firm specifications ar e aval table with special testing a t extra charge.

2 Specla I optics and testing required. There Is an extra charge for th e test ing which Is necessary toguarantee performance at these wavelenths. This Is available at time of purchase or at a Spectra-PhysicsService Center.

3 Not specified.

1-9


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CAUTION

The Spectra-PhysIcs Mode I 168 Laser Is aClass IV-High Power Laser whose beamIs , by def in i t ion, a safety and f i rehazard. Take precautions to preventaccidental exposure to both di rec t andref lected beams. Diffuse as well asspecular beam re f lectlons can causesevere eye or skIn damage.

PRECAUTIONS FOR THE SAFE


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SQ\miLE


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FIGURE 2.5: Model 1688 Radiation Control Drawing

La ser Sa fe ty FeatureCertification LabelWarning LogotypeAperture LabelCover Interlock LabelElectromagnetic Rad iation LabelRemote Contr ol (In t er lock) PlugPower Supp ly Em ission IndicatorBeam AttenuatorMASTER Key SwitchLaser Head Emission IndicatorCover Inter Iock

LOC8tlon

23456789

1011

2-3

~ SPECTRA-PHYSICS INC.J1250 WEST MIDDLEFIELD ROADMT. VIEW, CALIFORNIA 94042MANUFACTURED:

MONTH YRMODEL :1688 S/NTHIS LASER PRODUCT COMPLIESWITH 21 CFR 1040 AS APPLICABLE

MADE IN U.S.A.Certification Label

WarnIng Logotype

VISIBLEAND INVISIBLELASER RADIATION ISEMITIED FROM THIS APERTURE

( AVOID EXPOSURE )Aperture Labe I

VIS I BLE AND INV IS IBLEHAZARDOUS ELECTROMAGNETICRADIATION WH EN OPEN ANDINTERLOCK DEFEATED*

' SEE MANUAL

Cover lnierlock Label

VISIBLE AND INVISIBLELASER RADIATION WHEN OPENAND INTERLOCK DEFEATEDAVOID EYE OR SKIN EXPOSURETO DIRECT OR SCATTEREDRADIATION *' SEE MANUAL

Electromagnetic Radiation LabelFIGURE 2.6: Model 1688 Warning Labels


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INSTALLATIONU ~ A C K I N G YOUR LASERInspect each component of the system careful ly asyou unpack f t . I f you notice any damage, such asdents or scratches on the laser head or power supply cases, broken knobs or switches, or a brokenplasma tube, noti fy the shipper and your SpectraPhysics sales representat ive Immediately. I f ,upon Insta l lat ion, the laser fa l ls to operate ormeet performance speci f icat ions, Spectra-PhysicswIl l arrange for repaIr or rep I acement wIthoutwaiting fo r your claim against the carr ier to besett led.Retain ff le shipping containers. I f you f i le adamage claim, you may need them to demonstratethat the damage occurred as a resu It of shIppIng.I f you need to return th e laser for service, thespecial ly designed crate assures adequate protect ion.

You wi l l f ind the fol lowing Items In the accessor i es k i t In which th is manual was packed:o A tool k i t that contains a ll of the tools you

wi l l need to al ign and maintain your laser,In c I udlng: fuses, extra hose washers, a se tof A I en wrenches for beam a I I gnment, a boxwrench for unlocking the magnet for a l ignment, a mirror wrench fo r mirror remova I ,forceps and lens t is sue for optics cleaning,a dispensing bott le for optics cleaning

0

0

0

Two water hoses fo r system cooling water: youwi l l need one hose for I n le t water and onefor outf lowOne water f i l t e r with three 25f! m f i l t e rcartr idges: one cartr idge Is packed In th eth e f i l t e r housingA small cardboard box that contains the highref lector mirror, a mirror wrench, and twosets of keys: a pair of master switch keysand a pair of gas fill switch keys

A large bal l dr iver for plasma tube removal Ispacked separately.In addit ion to these accessories, you wi l l need tosupply several Items, Including:0 electronic grade (o r better) acetone fo r op

t ics cleaning

3-1

0 severa I ba I I drIvers fo r pI asma tube a I I gn ment 230 Vthree-phase Is avai lable, you must use atransformer to step down to 208 V.Contact your Spectra-Physics f ie ld engineer for detai ls .

Place both th e laser head and power supply Inthei r operating posi t ions. The standard length ofth e umb Ill ca I between the I aser and th e powersupply Is 2. 4 m. Connect th e electr ical umbil icalto th e receptacle on the rear panel of the powersupply; Insert th e plug Into th e jack and pressunt i l the connection Is snug. Tighten the reta inIng r ing f inger- t ight .WATER CONNECTIONS

Connect the laser head water hoses to the f i t t i ngslocated beneath the electr ical umbi l ical . Coolingwater may be supplied from an open-loop systemconsist ing of f i l tered tap water source and directconnection of the outflow to a drain, provided thewater flow r11te Is at le11st 8. 5 1/mln (2.2 USga I /m1 n) at a d I f ferent l a I pressure* between 2.11and 3.52 kg/cm2 (30 11nd 50 psi g.) The Incomingwater service should be at least 3/4" diameter.

*defined as th e difference between the ex i tback pressure 11nd the Input pressure


20/57

Overpressure Relief Outlet Remote Control Plug Umbilical Connector

Water Inlet Water OutletF IGtiE 3.1 : llbllt I 265 Reer Pane I

A 25 w ~ t e r f i l t e r Is Included with your l ~ s e rsystem. I t prevents blocked w ~ t e r p ~ s s ~ g e s by re moving p ~ r t l c l e s from the cool lng water. l n s t ~ l lIt with 21 shutoff v t ~ l v e on the In let sidecheck v t ~ l v e on the out le t side. Provide enoughroom around the f i l t e r to t ~ l l o w easy access fo rservice.Connect the f l l tered cool lng water to the f e m t ~ l ehose f I tt l ng on the r e ~ r pane I of the power supply . Connect d r ~ l n hose to the !Mle hose fit-t ing.

An over-pressure reI le f va I ve protects the l ~ s e rpower supp I y from d ~ m a g e due to hIgh water

pressure. It wl I I open I f cool lng system pressureexceeds 3.5 kg/cm2 . Connect anotherdrain hose to the over-pressure f i t t ing . Bothdrain hoses IMY be merged with "Y" connectionbefore they reach the d r ~ l n . However, I f a "Y" Isused, take ~ r e to avoid stepping on the out le thoses, which ~ n cause excessive back pressure.A closed-loop cooling system, such the SpectraPhysics Model 314 Water Conditioner IMY also beused. I ts specif ications,the ther!MI p ~ r a m e t e r s of

I I sted be low, exceedof the l ~ s e r s

3-2

In the Spectra-Physics 160 series. I f you p l ~ n todesign your own closed-loop system, use the specif icat ions and thermal p a r ~ m e t e r s a guide.

FIGURE 3.2: Model 1681265 lon Laser The.-.alP a r a ~ ~ e 1 ' e r s

Required He21t DissipationRequired Coolant Flow RateMaximum Outlet TemperatureRequired Coolant Pressure*

13.1 kW8. 5 1/mln2.2 g ~ l l m l n53C ( 127F>30-50 ps i g

FIGURE 3.3: Model 314 lon Laser Waier


21/57

FIGURE 3.4: U1"1111"y Requlre.an-ts fo r Model 168 Jon LasersUnder Wors-t easel Service Condi-tion s

Laser Maximum Maximum Temperature PowerVersion Outlet In let Change Consumed

Temp2 C"Fl Temp3 ("Fl C"Fl CkWl

-06,-16,-46,-56 127 95 32 10 . 4-07,-17,-27,-37, 127 91 36 11.6-47,-57,-67,-77-08,-18,-28,-38 127 88 39 12.6-48,-58,-68,-78-09,-19,-29,-39 127 85 42 13.5-4 9 ,-59,-69,-79-11 ,-21 ,-01,-31 127 88 39 12.6-51,-61,-71,-41

AC CurrentRequlred4

CAl

2831

34

37

34

224.6 V (acl (maximum specified) and 2.2 g/mln (minimum specified) cooling water flow2 Preset at the factory- temperature a t which the thermal Interlock opens34 Inlet water temperature must be below this value for safe operationCurrent rating of the three-phase circui t that serves the laser should be at least

10 A higher than this value.

3-3


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High Reflector Mirror Mount

~ - ~ \ Verti/justment

Horizontal AdjustmentFIGURE l .5 : l.aser Heed ln'hlrlor c-- . EM!)

Output Mirror MountWater Connection

Cavity Seal

Horizontal Adjustment Reservoir

F l ~ 1.6: Laser Heed ln"htrlor CCafflode End)

3-4


23/57

OPERATION

FIGURE 4.1 : Model 265 Power Supply Fron-t Panel

POWER stPPLY a:Jff'Tml.StTER- the mult i - funct ion meter displays plasmatube current, Iaser output power, gas pressure asa function of tube voltage, and th e operatingcondition of the tube current regulator.

FIGURE 4.2: Fron-t Panel Mlt'htr

tTER function se lec1'or - determInes the va I uedisplayed on th e panel meter.

4-1

50 AMPS - the metercurrent from 0 to 50 A.on th e D-50 seale.

displays plasma tubeRead values displayed

5 W - the meter displays output power from 0to 5 W. Read va Iues dl splayed on the Q-5seale.1 W - t he meter displays output power from 0to 1 W.scale.

Read values displayed on the Q-1

FILL the meter displays plasma tubepressure as a function of tube voltage.Optimum pressure ranges for argon and kryptonversions of t he Model 168 are color coded onthe meter face: Ar/blue Is fo r visible argonoperation; Kr/red Is fo r krypton operation Inthe red (647.1-799.3 nm) range; Kr/green Isfo r a I I other krypton II nes. I f the meterde f lect lon, at maximum CURRENT, fa I I s withinthe color bar corresponding to th e operatingwavelength of the laser, tube pressure Iswithin I ts optimum range.


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I f the meter fa l ls to reach th e color bar,gas pressure I s to o I ow and th e tube shou I dbe f ! l i ed .Mu l t i p l y values displayed on th e 0-50 scaleby a factor of s ix to f ind th e actual tubevo I tage. I f the meter def lects beyond th eco lo r bar, the tube Is over f i l led . Refer toth e "Gas F i l l " Inst ruct ions for deta i l s .REG - the meter displays the voltage acrossth e plasma tube current r egulato r by f indingth e difference between th e supply l ine vo l t age and the plasma tube voltage. I f th e mete r def lect ion Is with in the green REG bar,th e regulator vol tage Is with in I ts operatingrange. I f th e def lect ion fa l ls to reach th eREG bar, th e current regulator voltage Is to olow. Low supply l ine vol tage or high plasmatube vol tage can both reduce regulator vo l t age. I f the meter def lect lon exceeds the REGrange, regulator voltage Is to o high. Ei therhigh supply l ine vol tage or low tube vol tagecan be th e cause. I f ei ther conditionarises, check th e tube vol tage by switchingth e meter display to FILL.

Mul t ip ly th e value displayed on th e 0-1 scaleby a factor of ten to f ind th e actual regulato r voltage.

CURRENT control knob- output power Is stab! I !zedby regulat ing th e plasma tube current. Current Ismaintained a t a selected value, Independent off luctuat ions In supply l in e voltage.When th e METER function selector Is In th e 50 AMPS

FIGURE 4.3: Maximum Plas.a Currentfor Model 168 Versions

Argon Versions

-06,-46 28A -16,-56,-97 30A-27,-37,-67,-77 30A -07,-17,-47,-57 32A-28,-38,-68,-78 32A -08,-18,-48,-58 35A-29,-39,-69,-79 35A -09,-19,-49,-59 38AKrypton Versions

-11,-21,-51,-61 30A-01 ,-31 ,-41 ,-71 . . 35A

4- 2

posi t ion, plasma tube current can be selected byadjust ing th e CURRENT contro l unt i l a predetermined value Is displayed on th e meter.When th e METER se Iec to r Is In eIther the 1 W or5 W pos I t t on, laser output power can be adjustedto a predetermIned va I ue by turn l ng the CURRENTcontrol .CONTR>L 14X>E swItch - se Iects eI ther th e CURRENTcontro l or LIGHT contro l mode.LIGHT control knob- output power Is stab! I !zed bysampling the output beam and compensating fo r f l u ctuat ions through feedback to th e plasma tube current regulator . Minor resonator misalignments,vol tage I r regu lar i t ies and other disturbances Inth e output beam can be compensated for In th eLIGHT contro l mode.When th e METER se Iector Is In eIther th e 1 W or5 W posi t ion, laser output can be adjusted to apredeterm l ned va I ue by turn l ng th e LIGHT contro I .The usable output range Is 100 mW to 2 W. To a llow th e stabi l izat ion c i rcu i t enough lat i tude tooperate proper I y, plasma tube current must be seta t least 2 A below I ts maximum rated value.Light stabi l izat ion during mul t i - l ine operation IsImpossible since there Is no way to assure there la t i ve s tab i l i t y of a l l of the l ines In th e output beam.FIELD control knob- adjusts the ax ia l magneticf leld along th e plasma discharge from 500-1000 G.The output power of some krypton l ines can be enhi!!nced on th e pump vers ton by reduct ng the magnet ic f i e ld . The 647.1 l ine Cl!ln be enhanced by30% and the 520.8 I I ne by as much as 80%.A separ!lte regulated power supply fo r th e magnetassures a stable magnetic f ie ld without r ipp le .There Is no poss ib i l i ty of noise or r ipple coupI t ng to th e output beam through th e magneticf le I d.MASTER OONTR>L - th e key sw I tch act l va te s th e sy stem and must be on before the c i rcu i t breakers Ci!lnbe closed. When It Is on the lamp wi l l glo w.Circuit Breaker- connects a l l power supply c i r cu i ts to th e 208 V ac supply l ine. It Is Interlocked with the water f low, cover, and temperl!lture


25/57

monitors to ~ s s u r e sate operation.LINE Indicator la!ips - monitor the three phaseI I ne vo I tages wIth respect to one another. AI Ithree lamps glow when power Is applied to theModel 265.WATER Indicator la!ips - the WATER ON lamp glowswhen water pressure and flow ar e suf f ic ient forsafe o p e r ~ t l o n . The WATER HOT Indicator glowswhen the cooling system output Is too hot fo r safe

o p e r ~ t l o n ; It goes outtemperature Is reached.quickly and the WATER

as soon as a safe waterSuch a change can occur

Indicator may only glowmomentarily after the laser shuts down.LASER Indicator laiiPs - the READY lamp glows whenthe system Is ready to star t , about 15 sec af terthe MASTER CONTROL key switch Is turned ON. Pressthe START button to send a high v o l t ~ g e pulse tos h r t the plasma discharge.

Horizontal

GAS FILL control - the key switch act ivates thegas f I II mechanIsm to Increase pI asma tube pres-sure. Refer to the "Gas F i l l " Instruct ions In theOperation section fo r detai ls . Improper use ofth e Gas Fi l l system can cause permanent pI asmatube damage. ( I f you have a krypton laser, referto Krypton Laser Operation fo r addit ional Instruc-t ions.)

LASER HEAD OONTRX..S

Horizontal - moves the optlca I axis of the mirrorhorl zonta I I y.Vertical - moves the o p t l c ~ l axis of the mirrorver t ica l ly .

ATTENUATOR- a mechanlca I shutter tha t blocks thebeam as It emerges from the output coupler.

FIGURE 4.4: High Reflector Mirror Adjus-t.anb

4-3


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TESTING

The following tests should be performed before youattempt to start your laser for the f irs t time.They are your final assurance that the systemarrived In proper working condition.WATER TESTING lHE PLASMA TUBE

Remove the laser head cover.Slowly open the water supply valve until you beginto hear the water f Iow.Check the following:0 Water shou I d enter the tube through the mag

net water fitting.o Check for leaks at the anode block (seeFigure 4.5), the hose clamps, and the connec

t! on at the rear of the power supp Iy. Checkfor water drops beneath the power supply.

If water leaks appear at the fittings or hoseclamps, tighten them to see If the leaks stop. Ifthey persist, shut of f the water supply, drain thetube and call your Spectra-Physics representative.

OONTROL


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FIGURE 4.6Ca>: Power Supply Control Operation Tests fo r Mode I 168B ton Lasers

OONOITION TEST EXPECTED RESULT

Circuit breaker OFF , remo t e con- Move c ir cu i t breaker to ON Circuit breaker should no t remaintrol p lug In socke t , position ONsw Itch OFFCir cuit breake r OFF , remote con - Move circui t breake r to ON C ircuit breaker should engage andtrol p Iug In socket, MA STER position remain ON; MASTER Indicator la mpSWItch OFF should glowMASTER sw I tch ON , remote contr o I Remove remote control plug Ci rcui t breaker shou Id turn OFFplug In socket , circu i t breake r fr om rea r of power supplyON

MASTER sw i tch ON, remo t e contro I Turn OFF wate r supply You shou Id no t be able to close thep l ug In socket, c ir cu i t breaker circui t breaker.OFF

When you restore the water suppl y,the WATER ON Indicator should glowand the circui t breaker shou IdremaIn ON ,

FIGURE 4.6(b) : Power Supply Control Operation Tests for Model 168 ton LasersOONJITION TEST EXPECTED RESULT

Cir cu i t bre a ker OFF, MASTER key Move c l rcu I t breaker to ON The circui t breaker shou Id notswitch ON position remaIn ON .Cir cu i t breaker OFF , MASTER key Move c l rcu I t breaker to ON The circui t breaker s hou l d engageswitch ON position and remaIn ON, The MASTER OONTROL

I nd lcator lamp should glow.MASTER key switch ON , circui t Turn of f water supply You shou Id not be able to close thebreake r OFF c i rcui t breaker.

When you restore the water suppl y,th e WATER ON Indicator should glowand the circui t breaker shou Idremain ON.

4-5


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STARTING niE ARGON LASER

2

CAUTIONThe output beam of th is laser Is asafety and f i re hazard. Avoid viewingthe beam direct ly or blocking the beamwith clothing or parts of the body.Piacea power absorbing shield In the beampath (see Laser Safety>.Check the l ine voltage; It should be between190 and 225 V; extended operatl on at th el im i ts of th is range Is no t recommended.Check that th e green power supply lead Is

connected to earth g-ound at the rna In swItchbox.

3 Turn the water supply on.4 Check the water temperature; I f It Is


29/57

control unt i l you ge t th e uni t lasing again.The curved output coupler should remain stationaryunder normal operating condit ions. I f I ts al ignment Is disturbed, real ignment may be time consum-Ing and tedious. Use only the high re f lec ioradjustw3nts to achieve peak power. I f , af teradjusting th e mirror, th e output performanceremains below speci f icat ion, refer to r ~ a l n t e n a n c e .WAVELENGTH SELECTION

For single- l ine operation the high ref lectoroptics assembly contains a prism and a f l a tmirror . The prism disperses the laser beam, bendIng Individual l ines according to thei r wavelen gth. A l ine wil l osci l la te I f I ts angle of re f ract l on through the prIsm matches the vert ca Irotat ion angle of th e prism. As you turn the vert i ca l adjust ing screw of th e mirror mount, th eangle a t which the beam str ikes th e prism wi l lchange and, with I t , th e wavelength of the l inethat wIl l osci l la te.The l ines can be Ident i f ied by thei r re lat ivepower, a comparison of which Is found InSpecifications. Posit ive Ident i f icat ion of weakerl ines requires a spectroscope.FIN:>ING PEAK OUTPUT POWER WITH lHE FIB.D OONTROL

The laser output power a t a given l ine Is direct lyrelated to th e strength of the magnetic f ie ld surrounding the plasma tube discharge. While mostl ines perform best at maximum f ie ld strength, someothers can be enhanced by reducing the f ie ld withthe power supply FIELD control .After you tune the laser to a given l ine and adj us t the high ref lector fo r peak output power, t rychanging the FIELD sett ing while using the powermeter to observe the change In output power.Adjust the f ie ld fo r maximum output power.I f your working output power Is less than the f u l lcapacity of the laser, adjust the FIELD controlfo r I ts opt mum va I ue before you make the f Ina Ipower sett ing using the CURRENT or LIGHT controls.GAS FILL(For krypton lasers refer to Krypton Laser Operat ion fo r Instructions.)When the plasma tube Is new, gas fill may be re -

4-7

qulred every few days of operation. After thef I r s t few hundred operatl ng hours, fIll wIl l berequired only af ter every several hundred hours.Low pressure Is Indicated by the fill alarm buzzerIn the power supply. Since gas distr ibut ion andpressure change during th e f i r s t few minutes ofoperation, th e buzzer should be Ignored unt i l a fte r 10 min has passed. I f It persists, Increasethe pressure In the fol lowing manner.Turn th e METER selector to FILL and set th eCONTROL MODE swItch to CURRENT. At fu I I CURRENTand FIELD th e meter should r ise to the color barthat corresponds to the gas type (argon orkrypton) and desired wavelength (see Power SupplyControls, METER selector for detal ls l . I f Itfa l ls to reach the appropriate color bar, turn theGAS FILL key switch fo r a fraction of a second.Recheck the meter. Repeat the fill sequence unt i lth e buzzer stops and the meter r ises to th ecorrect color bar.Avoid over f i l l ing th e tube. Excessive gas pressure causes the maximum possible current to decl ine thereby decreasing maximum output power. I fthe tube becomes overf Tiled, contl nued operationwIl l eventua I I y return the pressure to I ts op t mumIeve I . The amount of t l me requIred to reduce gaspressure depends on the age of the tube and thedegree of over f l l l ing.atANG I NG


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Always al ign your laser for peak output power be -fore removing any of I ts opt ics. The ln tracavl tyspaces of th e Mode I 168 ar e sea led at the factoryto maintain cleanliness of th e mirrors andwIndows. I f you must c I ean th e ml r rors, remove,clean and replace them one at a t ime.

NOTE

The lntracavlty spaces should no t remainuncovered fo r more than a few minutes ata t ime.

Repeak the output power, adjusting only the mirrorthat was removed, af ter each opt ic Is replaced.Your laser wi l l usually operate at fu l l poweraf ter changing opt ics. I f a signi f icant powerloss occurs, t ry removing, cleaning and replacingthe mirror again. I f the problem persists, re ferto Maintenance.

Under normal operating condit ions, the outputcoupler should no t need realignment af ter a mirrorchange. Avoid tampering with output coupler con-t ro ls unless you are certain that It Is misal ign-ed ; realignment can be time consuming and tedious.

4-8

Hold the mirrors with thei r coated surface ontop. To reach the high ref lector unscrew th eblack nut with the mirror wrench. Push the mirrorout wIth a cotton swab. Use f Inger cots to hoI dthe mirror. Reverse th e sequence to rep lace themir ror . Removing and replacing the high ref lectormay throw the mirror ou t of alignment.

SHUTDOWN PR>CEDURE

( I f you have a krypton laser, refer to KryptonLaser Operation fo r Instruct ions.)

2

3

4

Shut o ff the c i rcu i t breaker.

Turn th e MASTER CONTROL key switch OFF andremove the key. Don't leave the laser acces-sible to people who ar e untrained In lasersafety or operation.Remove th e key from the GAS FILL switch.Walt a t least 15 sec for the pl11sma tube tocoo I , then turn o ft the water supp I y.


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F IGURE 4.1: MX>EL 168 OPTICS OPTIONS

Argon Ion LaserLaser Version A Output Broad Band Prism Remarksnm Coupler High Ref lector HIgh Ref lector

-06,-07 , -08, - 09 457 . 9- 514.5 G3861-001 n/a G3801-010 Prism TEMoo-46,-47,-48 , -49 528 . 7 G3861-003 n/a G3801-013 Prism TEM 00109 0 G381 2-006 G3812-005 n/a Prism TEMoo

-27,-28 , -29 , 457 . 9- 514.5 G3808-017 G3808-018 n/a Broad Band Multlmode-67,-68,-69 457 . 9- 514.5 G3808-017 G3808-018 n/a Broad Band Multlmode-16,-17,-18 , -19 457. 9- 514.5 G3861-001 G3802-009 n/ a Broad Band TEMoo-56,-57,-58,-59 457.9- 514.5 G3861-001 G3802- 009 n/a Broad Band TEMoo-37,-38,-39 457 . 9-514.5 G3808-017 n/a GOOOl-003 Prism Multlmode-77,-78,-79 457. 9- 514.5 G3808-017 n/ a GOOOl-003 Prism Multlmode

Krypton lon LaserLaser Version A Output Broad Band Prism Remarksnm Coupler High Re f lector High Ref lector

-01,-21,- 41, -61 647.1 - 676.4 G3812-012 G3812-011 n/a Broad Band TEM 00-11,-31,-51 , - 71 647.1-676.4 G3808-001 G3808-004 n/a Broad Band Multlmode

Op-tics HoldersBeam Sp II t te r 421-624-2 Broad Band 421-626-2 Prism 423-600

4-9


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MAINTENANCE

I f you notice a s ign i f icant drop In power, thesource of the prob Iem wIl l probab I y be one of thefo l lowing: d i r ty optics (output coupler, high re f lector , or prism>; d i r t y plasma tube windows;misaligned optics; or misaligned plasma tube.The procedures In th is section allow you to solvethese problems, thereby returning your laser tooptimum output. They are provided In the order Inwhich you should perform them.0 Clean the opt ics .0 Clean the plasma tube windows.0 All gn the optics.0 All gn the plasma tube.

The most probable cause of poor performance Isdir ty optics, therefore they should be cleaned before you t ry anything else. I f , af ter cleaningthe optics, the laser s t i l l performs below expecta t ions, clean the plasma tube windows. Then, I fnecessary, al ign the opt ics . Fina l ly , I f a l l elsefa l ls , al ign th e plasma tube. The procedures ar eprogressive In nature; I f you achieve success atto the next.

Output Coupler Plasma Tube Bore/t I- - - ----1---- - - -

The Mode I 168 resonator Is desIgned so that th eplasma tube bore, the center of the aperture, andthe centers of both mirrors l ie on the same I Jne:th e reson ato r axIs (See FIgure 5. 1 ) In order fo rthe laser to provide optimum performance, threecondit ions must be met:o The l ine defined by the plasma tube bore must

be centered on the resonator axIs.o The high re f lec tor must be perpendicular to

the resonator axis.o The center of curvature of the output coupler

must be on the resonator axis.Your laser Is factory aligned and should performto speci f icat ions without real ignment.I f th e laser has been cleaned and aligned, and youare sure that It Is producing maximum power, butI ts performance remains below speci f icat ion,ei ther the plasma tube or a power supply c i rcu i thas fa i led. Call your Spectra-Physics Servicerepresentat ive In th is case.

High Reflector

\

Resonator Axis Center of Curvature

FIGURE 5.1: Schetlatlc Representation of Ideal Resonator Allgnllltflt

5-1


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NOTES ON lHE O..EAN ING OF LASER


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coupler, which has two surfaces to becleaned, has to be removed.

FIGURE 5.2: Cleaning 1he Mirror Surface5 Remove the mIrror from the hoI der. HoI d the

mi r ro r with I ts coated surface horizontal andsqueeze out a drop or two of acetone to coverl t. Place a piece of lens t issue on thewetted surface and gently draw It across tof loat away dissolved contaminants.

6 Invert th e mirror and clean the secondsur face.

7 Replace the mirror In the mirror holder.

8

9

10

11

The arrow on the edge of the mIrror shou I dpo in t away from the cup. Note: th e white Teflon'" 0 r ing In the mirror holder may havecome loose. I f so, center It Inside theholder and force It Into the Indentationwhich Is there.S l ide the mirror and holder beck Into theopening In the mirror mount plate, mirror endf I r s t . SI I de the beam sp I I t te r assemb I yback, I lnlng up the dowel pin with the s lo tIn the aperture.Screw In the bleck plast ic ring with themi r ror wrench.Sl ide the cavity seal and nut toward the outpu t coupler. Screw f i r s t the small nut, thent he l erge nut onto the a ~ v l t y seal, f ingert ight.Follow a simi lar procedure fo r the highrelector.

5- 3

Cleaning the Prls.Un screw the prism housing cap to gain accessto the opt! ca I surfaces.

2 Do not remove the pr ism from I ts mount; Itcan be cleaned In I ts mount.3 Blow away dust part ic les or l i n t using

nitrogen or a i r .4 Fold a piece of lens t issue Into a pad about

1 on on a side and clamp It In a hemostat(see Figure 5.3). Saturate the pad withacetone, shake off the excess, resaturate,and shake

FIGURE 5.3: lens Tissue Folded for Prls Cleaning5 Wipe one surface of the prism, bottom to top,

In a single motion. Be carefu I that the t ipof the hemostat does not scratch thesurface. Repeat the operation with a clea nt issue on the other prism surface.A clean prism surface wil l scatter l i t t le orno II ght when the laser Is opera+! ng .

6 Replace the prism cap and adjust the mirrormount for maximum output power.7 Reseal the lntracavlty spaces promptly.

O....EAN ING PLASMA TUBE W !O>WSThis Is a progressive procedure designed to enableyou to remove even the most stubborn contaminatingf i lms. I f you achieve success before you completee I I of the steps, those that remaIn are opt! on a I .


35/57

Having begun a numbered step, be sure you fol lowIt through to completion. Failure to do so mayleave additional contamination on th e windowsurface.Equlp.ent Required0 forced a ir supply or dry nitrogeno photographic lens t issue00000

0

0

0

cotton swabshemostatdeionized or d is t i l led waterhydrogen peroxide , 5% solutionprerinse solut ion, composed o f:

1 part n i t r ic acid 19 parts deionized water17 parts methano I (CH 3oH)calcium carbonate (CaC03> - primary standardpowder, 600+ mesh - per American Chemical

Society specificationsMall lnckrodt 4071, 4072, or equivalent

Micro Detergent, manufactured by :International Products CorporationP.O. Box 118Trenton, NJ 08601

three empty bott les to hold the cleaningsolutions l isted below

A k i t , composed of the above materials Is avai l -able from Spectra-Physics (part number OOOQ-0013).Cleaning Solutions Requiredo spectroscopic grade acetone CCH 3COCH3>o spectroscopic grade methanol CCH 30Hl0 Oaklte 33, manufactured by :

Oaklte Products, Inc.50 Va I ley RoadBerkeley Heights, NJ 07922

Procedure

2

Use compressed a ir or dry nitrogen to blowdust part ic les and l in t away.Fold a lens t issue pad, clamp It In the hemostat, and saturate It with methanol. Shakeo ff the excess, resaturate, and shake agal n.(See Fl gure 5.2>WIpe the wIndow wIth a sIngle stroke frombottom to top. Most contamination can beremoved with this step alone.

5-4

3

4

5

6

Fold another t issue and saturate It withacetone, as above. Wipe the window again.Follow the acetone with another methanolwipe, using a clean t issue pad.Saturate a cotton swab with 5% hydrogen peroxide; use a ci rcular motion to clean the entl e wIndow surface.Follow the H2o2 with another methanol wipe,using a clean t issue pad.Saturate a cotton swab with Oaklte 33'"; use aci rcular motion to clean the entire windowsurface.Rinse using a cotton swab saturated with de Ionized water; repeat three t imes, using afresh swab each t ime.Follow the deionized water with anothermethanol wipe, using a clean t issue pad.Use a cotton swob to wet the ent i re windowwith prerinse solut ion. Dip a cotton swab,wet with prerinse, l ight ly Into calcium carbonate powder; th e result ing paste shouldhave the consistency of toothpaste. Scrubthe window surface, using a circular motion,for about 30 seconds.Dip a dry cotton swab In the ca lculm carbonate powder and scrub the wIn dow agaIn. Theadditional powder wil l dry the paste remainIng from the previous step.Rinse with a cotton swab saturated with prerinse solution.Saturate a cotton swab with Micro Detergentand clean the mirror surface using a circularmotion.Rl nse the surface three t l mes usIng cottonswabs saturated with deionized water.Follow the deionized water with anothermethono I w pe, usIng a clean t l ssue pad.

7 Reseal the ln t racavl ty spaces promptly.ALIGNING MIRRORS

Patience and attent ion 1o detai l are required to


36/57

assure proper alignment. First , the laser mustbe tuned fo r apparent peak power. Then the beammust be "walked" along the paral le l mirrors unt i lyou have determined, by t r ia l and error, that noadditional power can be coaxed from the uni t .

Adjusting the Mirrors For Apparent Peak PowerWhi le monitoring the output with an external powermeter, turn one of the ml r ror adjustment contra Isback and forth unt i l the output Is at I ts peak,then turn the other. Repeat the adjustments,f 1 s t turn 1ng one contra I , then the other, backand forth untl I no further power Increases areattainable. Make a note of the output power."Walking the Mirrors to Assure Peak Power

F igure 5.4 I l lust ra tes an arrangement of cavitymirrors that wil l allow lasing, but with reducedoutput. A s l igh t tilt of the high re f lectorcompensates fo r a simi lar tilt of the outputcoupler. The result ing beam Is skewed with respectto the resonator axis and the plasma tube bore.Under these condit ions, the laser can be "peaked",but th e output wil l be less than optimum becausepart of the beam Is obstructed by the bore wal Is.

FIGURE 5.4: Misaligned Mirrors Cause Lasing a tReduced Power

Walking the mirrors Is a t r ia l and error procedurethat assures optimum mirror a II gnment. The goalIs to al ign the ln t racavl ty beam with the resonator ax is by making small adjustments of the highref lector and matching them with adjustments ofthe output coupler. By observing the change Inoutput power as you move the mirrors, you wi l lf ind the o p t l m u ~ alignment posi t ions.Once the high ref lector has been pellked, detuneone of I ts controls unt i l the output Is about 50%of I ts peak value. Move to the other end of thelaser and turn the corresponding output couplercontrol In the same direct ion.Be carefu I I Use the same contra Is on both ends of

5-5

the laser and turn them the same direct ion, thatIs , I f you turn the high ref lector vert ical cont ro l clockwise, turn the output coupler vert icalcontrol clockwise (keeping the same point of viewas before). I f you lose lasing, reverse the d i-rection of mirror movement unt i l lasing Is re stored.Observe the change In output power as you turn themirror contro l ; I f the output peak exceeds theor ig inal value, walk the mirrors In the same d i-rection. Repeat unt i l the power reaches I ts peak.I f the output fa l ls to reach the or ig inal value,return both controls to their original posit ions.Walk the mirrors with the other pair of controls.I f you f i r s t walked the vert ical mirror controls,do the same with the horizontal controls or vice-versa.Remember, always walk the mirrors In the direct ionof Increased output power; I f the power starts todecl ine, go the other way. Also, always f ind thepeak power with one set of controls before movingto the other set; f in ish with the vert ical cont ro ls before you move the horizontal controls andvice versa.Repeat the walking process several t imes, f i r s twIth one set of contra I s, then wIth the other.Continue unt i l the output power Is as high as I tcan go .ALIGNING lltE PLASMA TUEE

u--t:j------ ~ --- --- ~ ---t=1--- - - ~ - - - - - - - - - - - - - - - - - - - - - - ~ - ~ - - - - - -

- v __- - - - - - - - - - - - - = = = ~ f - - - - -B _J_- - - - - - - ~ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - t = 1 - -FIGURE 5.5: Misaligned Plas.a Tube Causes

Lasing a t Reduced PowerFigure 5.5 I l lust ra tes two l lrrangements of thecavity elements In which the plasma tube Ismlslll lgned with respect to the resonator axis. In


37/57

the f i r s t , th e tube Is skewed, and th e mirrorshave been aligned to compensate. In th e second,th e cavity mirrors are aligned to r optimum output,but the tube Is skewed. Both problems cause suboptimum output.

The to t lowing procedures center th e plasma tubebore on the resonator axis, thereby enabl ing th elaser to produce maximum output power. Use an external power meter to monitor the alignment of th eplasma tube.Remove th e f ront and rear cavi ty seals and loosenth e lock lng screws at both the anode and cathodeends of the magnet (see Figure 5.7) .Adjust the horizontal posi t ion of the cathode endby working one adjusting screw against the other;adjust unt i l you achieve maximum output power.Move to the anode end and repeat the horizontaladjustment.

Adjust the vert ical posit ion of th e anode end until you achieve maximum power. Move to the cathode end and repeat th e vert ical adjustment. Repeat the adjustment sequence unti l no further In -crease In power occurs; the plasma tube al ignmentIs "peaked".Reduce the current to the lowest va I ue that wIl ls t l I I allow lasing and observe the position of th ebeam on the hIgh re f Iector. I f th e beam Is notcentered, move It by walking th e mirrors.Determine th e axis, ei ther horizontal or vert ica l ,a long whl ch the beam must t ravel and adjust theappropriate controls. Monitor the output power asyou walk th e beam toward the center of th emIrror. I f the power drops sIgn It cant I y, adjustthe tube position to repeak the output power.Tube and mirror adjustments Interact with oneanother, so you wil l probably f ind It necessary torepeat the sequences several t imes, f i r s t walkingthe mirrors, then moving the tube, then walkingthe mirrors again, and so fo r th . After severalrepet i t ions you wi l l reach a point where th e lastpossible ml l l lwat t has been coaxed from the laser.PRISM A L I ~ N TFigure 5.6 Identi f ies th e adjustment screws youwil l use In the alignment procedure. V Is theprism mirror vert ical adjustment screw. Two hex

5-6

v

FIGURE 5.6: Prl s A I I gn .mt Adjusta.ent Screwsnuts, one on each side of the mirror mountingplate, determine the plate posi t ion. By looseningone nu t and t ightening the other, you can move th eplate toward or away from th e prism, thereby adjusting the vert ical movement of the mirror . H1Is th e horizontal prism mirror adjustment and Hzlocks the horizontal posit ion of the mir ror .PI ace a paper target around the anode end of theplasma tube and use the high ref lector adjustmentsto peak the laser In broadband. Remove the broadband high re f lector .Remove the prism dust cap and loosen Hz and th enuts around V. Grasp the sides of the prismassembly and Insert It In the rear mirror mount.Using H1 and V, move the mirror unt i l the re f lec-te d bore l igh t str ikes the paper target Immediately be low the center of the p l < ~ s m a tube.Rock the high re f lec tor mirror mount back andforth by app I y I ng pressure near the end pI atevert ical < ~ d j u s t m e n t . Whl le you rock the endp < ~ t e , turn H1 to move th e prism mirrorhor I zonta I I y. Continue the rockIng and hor I zontl! Imovement unt i l you see a f I ash of Iaser I I ght.Use the nuts on V to adjust the prism mirrorvert ical posit ion unt l I the uni t l < ~ s e s . Adjust H1for peak power, then t ighten Hz I t th e outputpower f < ~ l l s upon t ightening Hz work H1 < ~ n d Hz

< ~ g a l n s t each other unt i l the prism mirror plate Islocked on I ts optimum horizontal posi t ion.Remove the prism < ~ s s e m b l y < ~ n d rep lace It with thebroad-band mirror . R e p e < ~ k th e laser. As th eassemblies are removed and Inserted, the posit ionof the mirror mount may be moved. In order to


38/57

Horizontal Alignment (Hidden) Loosen Before Alignment\

Vertical Alignment Loosen Before AlignmentHorizontal AlignmentCathode End

Horizontal Alignment~ ( H i d d e n )

Anode End

FIGURE 5.7: P las - Tube Alignmen-t Adjus-t.en"ts

5-7


39/57

keep It In I ts optimum lasing posi t ion, you mustrepeak the laser In broad band from time to t ime;use only th e high re f lec tor adjustments.Reinstal l the prism. I f the uni t fa l ls to lase,repeat the prIsm ml r ror a I I gnment sequence. I fth e uni t lases, observe the color of the beam.I f the laser beam Is green, lock the prism mirrorIn place . Remove the prism assembly and t ightenv1, then t ighten v2 and re insta l l th e prismassemb I Y

I f th e laser beam Is blue-green or blue, the prismmirror plate needs to be moved away from theprism. Alternate t ightening v1 and loosening v2unt i l the beam Is green.Horizontal and vert ical adjustments may Interactso you may have to repeat the prism mirror al ign-ment sequence several times unt i l fu l l lnterchangab l l l t y Is achieved. Remember to repeak th e laserIn broad band periodically to maintain the re fer -ence point at which the prism wi l l Interchange.Restore the reference po l nt af ter two or threeprism mirror adjustments.

REPLACEMENT PARTS

5101-0300 Fuse 2A2 5101-0310 Fuse 1/4A3 5101-0090 Fuse 3A4 5101-0240 Fuse 8A5 5101-0280 Fuse 6A6 5101-0270 Fuse 5A7 5101-0070 Fuse 1/4A-5B8 2604-0070 Water Fi l te r Cartr idges*

* "F I I te r l te " cartr idges are manufactured by Sl iver Screen, part number 4-10.Contact your local "FI I ter l te" d is t r ibu tor .

5-8


40/57

TROUBLESHOOTINGThe f o l lowing Information wi l l help you solve somecommon problems tha t arise with the Model 168/265.For In f ormation about factory repair of the laseror power supply, see Customer Service.

SAFE USE Of TEST EQU I P ~ TTh i s I nstrument Is connected direct ly to a highcurren t power II ne and a I I centro I cIrcuIts areat or near l ine potent ial with respect to ground.It Is f.-possible 1o safely raeasure ffle voltagesor wavefors within th is fnstru.ant with tes tequfpraent that has a !TOUnded case. or probeconnections. or both. An unintentional grounding

S Y ~ T O M : Cl RaJ IT EREAKER liON' T TURN CJilProbab l e CauseInsuf f ic i ent water flow

Remo te control plug absent or misaligned

MASTER CO NTROL key switch OFFDe f ec t iv e Ci rcu i t Breaker

S Y ~ T O M : CIROJIT IREAKER TRIPS OFFProbable CauseIn l et water temperature above 35C C95F)

S Y ~ T O M : PLASMA TUBE FAILS TO IGH ITEProbable CauseBl own fuse

5- 9

of th is equipment can cause powerful arcs andextens lv e damage to electronic components. Mostc i rcu i ts can be checked using a battery poweredmu I t lmeter.The safest troubleshooting method for the Model168/265 Is to check the equipment with an ohmmeterwhile the laser head and power supply are "cold"(power o f f ) . Measuring the resistance of semiconductor components wi l l Identi fy most common problems. It Is possible to test the l ight stabi -l izer , the magnet regulator , and a ll thresholdc i rcu i ts without start ing the plasma dischargecurrent.

ThIngs to CheckIn le t water may be too hot; the WATER HOT lamp onthe f ront panel of the power supply only glows mo-mentari ly before the Inter lock t r ips ; It wi l l goout soon af ter the power supply shuts down.

Check the seating of both the cover Inter lock andremote control plug.Turn MASTER CONTROL key ON.Turn the main power o f f . Jiggle the Circu i tBreaker: I f It seems wobbly, the Ci rcu i t BreakerIs defect ive. Contact your Spectra-Phys lc s Service Center to have It replaced.

Things to CheckCheck the water service flow rate. The In l ine25 IJm f i l te r m11y be d i r ty . A separate f i l te rprotects the flow switch; remove the bottom panelfran the power supply to gain access. Check I tscondit ion and clean or replace I t , I f necessary.

Things to CheckCheck power supply fuses bene11th top cover, behindf ront panel.


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S'M"TOM: PLASMA TUBE FAILS TO IGNITE

Probable CauseHIgh pI asma tube pressure

Tube vacuum Is lost ; tube Is "up to a i r "

S'M"TOM: LOW OUTPUT POWER

Probable CauseDirty optics

Incorrect control sett ings

Improper optics

Misaligned Mirrors

Misaligned Plasma Tube

Defective Magnet

5-10

Things to CheckI f possible, check past performance for lndlcat l ons of overt I Ill ng . Low tube current or hIghtube voltage are manifestat ions of high gas pressure. Tube replacement Is the only sure cure.I t the getter, a s I I ver mater I a I deposIted nearthe cathode, has turned milky or has disappeared,or I f a black, f laky deposit Is found on the f l la -ment, the vacuum seal of the tube Is most l ike lybroken.

Things to CheckRemove and Inspect one mirror a t a t ime. I tei ther Is unclean, refer to "Cleaning Prisms andMirrors" In Maintenance. Repeak the mirror mountto maximum output power each time you replace amirror . Inspect the plasma tube windows, I fei ther Is unclean, refer to "Cleaning the PlasmaTube Windows" In Maintenance.Double-check the CURRENT or LIGHT control sett ing.Check th e FIELD contro I set t l ng . I t you areoperating with single- l ine output assure yourselftnat th e laser Is tuned to the desired wavelength. Check th e METER selector; are you readingth e correct power scale?Check the opt ics to see I f they are coated fo r thewave length to which the laser Is tuned by comparIng th e part number on th e mirror with the partnumber In the opt ics l i s t . This Is especial lyImportant with krypton lasers.

Repeak and walk th e mirrors as described In"Mirror Alignment" In Maintenance.Realign the plasma tube as described In "PlasmaTube Alignment" In Maintenance.Switch the METER selector to the FILL position andturn th e FIELD control back and for th. The tubevoltage should swing three to four divisions onthe meter sea Ie.


42/57

SYWTOM: ~ CANNOT 11:: RAISED 10 MXUU4Prob11ble CauseHigh g11s pressure

Low I I ne vo I 11 ge

Probable CauseShort c i rcu i t , blown fuseBl own passbank

SYWTOM: f> OUTPUT II::AM. PLASMA TUBE GLOWSIt i l ICATI NG 0 I SOiMGE

Probable CauseSeverely misaligned rear end plate

FIGURE 5.8: Yertlca I Search

5-11

Things to CheckUse the FILL meter, or an external voltmeter, tocheck tube voltage.

CAUTIONAvoid shorting the anode block tothe magnet wIth tt-e meter probe 1.

Do not connect an externa I meter unt l I tt-e tube Isst11rted. I f the voltage Is >250 V, the tube Isprobably over f i l led. Be sure the CURRENT andF IELD con t ro I s are set to max I mum va I ue . Checktt-e magnet condit ion.I f tt-e I lne volt11ge Is too low,


43/57

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48/57

KRYPTON LASER OPERATIONTHE IClOEL 168 KRYPTON

AUTOMATIC PRESSURE CONTROL PUMP LASER(Versions 168-41,-71,-01,-31)

STNHUP PROCEDURECAUTION

The output beam of th issafety and f i re hazard.

laser Is aAvoid viewing

the beam dIrect I y or I ntercept l ng thebeam with clothing or parts of the body.Piace a power absorbing shield In thebeam path (see Laser Safety) .

The output power and discharge character ist icsof krypton I on I asers are no t as stable as thoseof argon lasers. The ef fec t of gas pressurechanges during warmup Is s ign i f icant , especial lyI t the laser Is tuned to a wave length other than647.1 nm. To minimize pressure change effects andavoid plasma Instabi l i ty during warmup, use thefol lowing startup sequence.

2

34

5

Check the l ine voltage; It should be between190 and 225 V ac .

Check that the safety green lead Is connectedto earff l ground.Turn on the water supp I y.Check the water temperature; I f It Is


49/57

LNof> OOtll IT ION PRESSUREOFFOKON LOWFLASHINGHIGH

FIGURE 6.1: Gas Fill Indicator

I f the l ight Is o ff or f lashing, repeat th isstep.

17 I f the pressure control Is of f , turn It on .

18

Walt unt i l the fill c i rcu i t raises the gaspressure, turnIng the Iamp o f f ; go to step16 .

Increase the current by 5 A and check thefill lamp. I f It Is on, walt unt i l the fillc i rcu i t raises the gas pressure, turning thelamp of f .

19 The optimum current Is the lowest va I ue tha twi l l produce the desired output power. I fthe current Is less than optimum or 25 A (themaximum current va I ue suggested during thef i r s t 30 min of operation) go to step 18.

Krypton pump versions of the Model 168 should beoperated In the CURRENT control mode for a t least10 min with a current l im i t of 25 A. Unti l thetube warms up enough to allow the gas toredistr ibute, higher currents wil l cause plasmaosci l lat ions which manifest themselves as a"chi rping" sound. I f allowed to continue fo r aprolonged period, the osci l la t ions wi l l causepower supply components to overheat. While Inth is condit ion the plasma tube voltage may reach10 kV peaks. Do not atteiiiPt 1o asure tubepressure I f your krypton tube Is chirping! Anyatfeii!Pt 1o cb so will short circui t th e nB"hJr andcause catastrophic power supply failure.

SHUlOOWN PROCEDURETurn the FIELD control to I ts maximum value( fu l ly clockwise.)

2 Move the CONTROL MODE swItch to the CURRENTpos I t l on and turn the CURRENT contro I to I tsmaximum value ( fu l ly clockwise.)

6-2

3

456

7

I f the FILL lamp glows, walt unt i l It goesout. By f i l l ing the tube before shutdown,you assure adequate pressure the next t l meyou turn the I ase r on.Turn the FILL switch OFF.Shut o ff the c i rcu i t breaker.Turn OFF the MASTER CONTROL key swItch andremove the key. Don't leave the laser accessible to people who are untrained In lasersafety or operation.Walt at least 15 sec fo r the plasma tubeto coo I then turn the water supp I y o f f .

To el iminate the need for lengthy warmup periods,plan to operate your krypton laser for a t leastthree hours each week.

ntE STNI>ARD fO)El 168


50/57

power supply components to overheat. While InthIs cond I t l on the pI asma tube vo I tage may reach10 kV peaks. Do no+ a11etlp+ 1n -asure +ubepressure If your kryp-ton +ube Is chirp ing! Anya+teiiP+ 1n do so v i i i shor+ clrcul+ 1tle e1er andcause catastrophic paver supply failure.

2

34

Check the I I ne vo Ita ge; It shou I d be between190 and 225 V (ac).Check that the safety green lead Is connectedto earth ground, not neutral .Turn the water supply on.Check the water temperature; I t It Is warmup,

th e tIll a I arm sounds wh I le you areIncreasing current or f ie ld, add one "buzz"of gas by turning the key switch momentarily,allowing just enough time tor the t l II systemto actuate the so Ienol d. Ll sten to r a buzzor cl ick from the solenoid.

Walt at least 30 min to r the pressure tostabi l ize before adding any more. I f th ealarm persists af ter 30 min add anotherbuzz of gas .I t , In addit ion to the till alarm, the laserstarts to chi rp, reduce the CURRENT unt i l Itstops and add one buzz of gas; walt a tleast 30 m1n to r the pressure to stabi l izebefore adding any more.

18 Continue to Increase th e CURRENT slowly,adding gas when prompted to do so by the tillalarm, unt i l It Is at maximum value. Walt a tleast 30 min between buzzes of gas.

19 Adjust the FIELD control to r maximum outputpower.

20 SwItch the METER se Iector to FILL and checkthat the meter r l ses to the color bar that


51/57

21

corresponds to th e desired wavelength (seePower Supply Controls, Meter Selector fordeta I I s .)I f th e meter fa l ls to reach the appropriatecolor bar, contact your Spectra-PhysicsService representotlve.

Non - pumping krypton plasma tubes are susceptibleto overt I I I , whIch sever I y I I m ts theIr performance and can cause tota l tube fa i lure . To prevent over f i l l ing and prolong tube l i f e , be sure toadd gas one buzz at" t ime. Whenever th e filla Iarm sounds, add one buzz of gas, then waIt a tleast 30 min to allow th e gas pressure tostab I I ize .The buzz Is , a t best, an Imprecise un i t ofmeasu r e . Your f i r s t buzz may produce an Increaseof 5 V af ter stabi l izat ion; the next may onlyyield 2 V. Since th e amount of change Isunpredictable , a stepwise "buzz and walt"procedure Is th e best way to avoid over f i l l ing .

SHUTDOWN PR>CEDURES

Turn th e FIELD control to I ts maximum va I ue( fu l ly clockwise).

6- 4

2

3

M:>ve the CONTROL f.()DE swItch to the CURRENTpos I tl on and turn th e CURRENT control to I tsmaximum value ( fu l l y clockwise).I f th e FILL alarm buzzes, add gas slowly, onebuzz a t a t lnB unt i l It goes o f f . By f i l l ingth e tube before shutdown, you assure adequatepressure the next tl meon . Remember to walt atbuzzes to a I low th estabi l ize. Switch the

you turn the I aserleast 30 min between

gas pressure tometer to FILL and

monitor the change In tube volts as youIncrease the pressure. Brl ng the pressure upto I ts optimum operating level beforeshutt ing the laser of f .

4 Shut o ff the c i rcu i t breaker.

5

6

7

Turn the MASTER CX>NTROL key swItch OFF andremove the key. Don't leave th e laseraccessible to people who are untrained Inlaser safety or operation.Remove the key from th e GAS FILL swItch.Walt at least 15 sec fo r the p l a s m < ~ tube tocool then turn th e water supply of f .

To el iminate the need for lengthy warmup periods,plan to operate your krypton laser fo r at least 3hr each week.


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CUSTOMER SERVICE

At Spectra-Physics, we take great pr ide In thedurabi l i ty of ou r products. Considerable emphasishas been placed on control led manufacturingmethods and qua I t ty control throughout the manu-f ac tur ing process. Despite th is fact , Instrumentsdo bre ak down In operation. We feel that ou rInstruments have favorable service records com-pared to competit ive products and we hope todemon st rate, In the long run, that we provideabove-average service to ou r customers-not onlyIn provIdIng the best equIpment fo r the money,bu t, In addi t ion, service fact I I t ies that ge t yourInstrument back Into action as soon as possible.Spectra-Physics maintains major service centers Int he UnIted States, Europe and Japan. Add I tl on a l l y , there ar e f ie ld service off ices In majorUnited States c i t ies . Call the nearest servicecenter or f ie ld service of f ice fo r assistance.Rep 1a cement parts shou I d be ordered dIrect y fromSpectra-Physics. For ordering or shipping In struct ! on s or for ass I stance of any kInd, contactyour nearest sa Ies off Ice or servIce center andg iv e th e Instrument model and seria l numbers.Service data or shipping Instruct ions wl l I bepromptly supplied.

WARRANTY

Unless otherwise specif ied, a l l Spectra-Physicsproducts are warranted to be free from defects Inworkmanship and materials fo r one year from th edat e of shipment. Spectra-Physics wil l repair orreplace Instruments which prove to be defectiveduring the warranty period without charge. Theobl igation of Spectra-Physics Is l imited to suchrepair , and does not extend to consequentialdamages.

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Simple ma I adjustments or unclean optics arefrequent causes of poor Instrument performance orfa I I ure and ar e exc I uded from warranty coverage.A service charge wll I be assessed I f an Instrumentwhich, when shipped to Spectra-Physics forwarranty repair , can be returned to operatingcondit ion by routine cleaning or adjustment.Always drain cooling water from the plasma tubebefore shipping. Water expands when frozen andmay shatter the tube; such damage Is excluded fromwarranty coverage.

RETURN Of THE INSTRUMENT FOR REPAIR

Contact your nearest Spectra-Physics f ie ld salesof f ice, service center, or local dist r ibutor forshipping Instruct ions, and forward the Instrumentprepaid to th e destination Indicated. SpecialSpectra-Physics packing boxes designed to securelyhold Instruments during shipment should be used.I f shipping boxes have been lost or destroyed, werecommend that you obtain a new one, for a nominalcharge, from Spectra-Physics. Spectra-Physics wll Ionly return Instruments In Spectra-Physics' conta iners.


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SERV ICE CLNTERS

WESTERN UNITED STAT ESSpectra-Physics IncLaser Products Division1250 WMiddlefie ld RdPO Box 7013Mountain VIew, CA 94039-7013EAST ERN UNIT ED STATES

Tel: {800l 227-8054Telex: 348488TWX: 910-379-6941

Spectra-Physics Inc Tel (NJl: {201) 981-0390366 S Ran dolphvlll e Rd (other): {800) 631-5693Piscataway, NJ 08854-4175 Telex: 710-997-9506BENELUX COUNTRI ESSpectra-Physics BVPO Box 22645600 CG EindhovenThe Nether lands

Te I: (040)45 18 55Telex: 51668

CANADA, LATIN AMERI CA, PACIFIC REGIONSpectra-Physics lnt ' I1250 WMid d le f ield RdPO Box 7013Mountain VIew, CA 94039-7013ENGLAND

Spectra-Phys lcs Ltd17 Brick Knoll ParkSt AlbansHertfordshlre , AL15UFEnglandFRANCE

Spectra-Physics SAAvenue de ScandlnavleZA de CourtaboeufEP 2891941 LES ULIS CedexFrance

Tel:Telex:TWX:

{415) 961-2550348488910-379-6941

Tel: (0727)30131Telex: 23578

Te I : 1 6907 99 56T Iex: 6911 83

JAPANSpectra-Physics KK15-8 Nanpeldal-choSh lbuya-kuTokyo 150JapanSWITZERLANDSpectra-Physics AGSchwelzergasse 394054 BaselSwitzerland

Tel: (03)770-5411Telex: 2466976

Tel: 708-0Slemensstrasse 20 Telex: 419471D-6100 Darmstadt-KranlchstelnF. R. Germany

F IEL.D SERVICE OFFICESAlbuquerque, NMBoston, ~Chicago, ILDayton, OHHouston, TXLos Angeles, CAWashington, DC

Tel:Tel:Tel:Tel:Tel:Tel:Tel:

{800) 227-8054{800) 631-5693(800) 631-5693(800) 631-5693(800) 631-5693(800) 227-8054(800) 631-5693

*CSSR, Denmark, Egypt, Finland, Greece, Ireland,Israel, Italy, Kuwait, Norway, Pakistan,Portugal, Saudi Arabia, Spain, South Africa,Sweden, Turkey, USSR, and Yugoslavia


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SPECTRA-PHYSICS INSTRUCTION 14\M

spectraphysics sp-164, sp-165 & sp-168 service manual

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