激光技術(shù)及應(yīng)用

激光的基礎(chǔ)、應(yīng)用及其發(fā)展LightAmplificationthroughStimulatedEmissionofRadiation引言基本原子、分子受激發(fā)射放大而產(chǎn)生的一種相干光輻射；極高的亮度，極好的方向性、單色性和相干性。

激光：Laser：激光的發(fā)明：1958激光名詞出現(xiàn)

1960第一臺(tái)激光器出現(xiàn)激光應(yīng)用：光學(xué)：激光物理，非線性光學(xué)、激光光譜學(xué)等新興學(xué)科工業(yè)：已廣泛地利用激光進(jìn)行切割、焊接、打孔、熱處理等醫(yī)學(xué)：外科手術(shù)刀，醫(yī)治很多疑難病癥信息：計(jì)算機(jī)、音視頻顯示設(shè)備等能源：激光核聚變環(huán)保：環(huán)境及污染監(jiān)測(cè)軍事：制導(dǎo)、測(cè)距、致盲和做未來(lái)高技術(shù)戰(zhàn)爭(zhēng)中的新武器

ArthurL.Schawlow

CharlesH.Townes

AleksandrM.Prokhorov

NicolayG.Basov

NicolaasBloembergenKaiM.Siegbahn1964年諾貝爾物理獎(jiǎng)1981年諾貝爾物理獎(jiǎng)激光是一種電磁波Lightisanelectromagneticwave.Differentwavelengthsinthevisiblespectrumareseenbytheeyeasdifferentcolors.lWavelengthRed:

l=700nm

Blue:

l=400nm

Laser-P

受激輻射IncidentPhotonExcitedAtomLaser-P

StimulatedPhotonsamewavelengthsamedirectioninphaseIncidentPhoton激光器的構(gòu)成工作物質(zhì)ACTIVEMEDIUMSolid(Crystal)GasSemiconductor(Diode)Liquid(Dye)激勵(lì)系統(tǒng)EXCITATIONMECHANISMOpticalElectricalChemical光學(xué)諧振腔OPTICALRESONATORHRMirrorandOutputCouplerTheActiveMediumcontainsatomswhichcanemitlightbystimulatedemission.TheExcitationMechanismisasourceofenergytoexcitetheatomstotheproperenergystate.TheOpticalResonatorreflectsthelaserbeamthroughtheactivemediumforamplification.HighReflectanceMirror(HR)OutputCouplerMirror(OC)ActiveMediumOutputBeamExcitationMechanismOpticalResonatorLaser-P

HELIUM-NEONGASLASERLaser-P

CourtesyofMetrologic,Inc.固體激光SOLIDSTATELASERLaser-P

HighReflectanceMirror(HR)OutputCouplerMirror(OC)EllipticalReflectorPowerSupplySolidStateRodArcorFlashLampSingleLampDoubleLampRearMirrorAdjustmentKnobsSafetyShutterPolarizerAssembly(optional)CoolantBeamTubeAdjustmentKnobOutputMirrorBeamBeamTubeHarmonicGenerator(optional)LaserCavityPumpCavityFlashlampsNd:YAGLaserRodQ-switch(optional)CourtesyofLosAlamosNationalLaboratoryNd:YAGLASERQ-開關(guān)StoredEnergyOutputPowerTimeWithQ-SwitchWithoutQ-SwitchLasingbeginswithoutQ-switchQ-SwitchopensQ-switchedPulse:1Jin10ns->100MW

NormalLongPulse:1.0Jin1.0ms->1KW

TimeHROCAMQLaser-P

半導(dǎo)體激光DIODELASERLaser-P

SiO2MetallicContact10-20mmCleavedFacetCurrentDistribution+-EllipticalBeamP-NJunction激光光譜LASERSPECTRUM10-1310-1210-1110-1010-9

10-810-710-610-510-410-310-210-11

10

102

LASERS20030040050060070080090010001100120013001400150010600UltravioletVisibleNearInfraredFarInfraredGammaRaysX-RaysUltra-VisibleInfraredMicro-RadarTVRadio violet waveswaveswaveswavesWavelength(m)Wavelength(nm)Nd:YAG1064GaAs905HeNe633Ar488/515CO2

10600XeCl308KrF2482wNd:YAG532RetinalHazardRegionArF193CommunicationDiode1550Ruby694Laser-P

Alexandrite755激光的特點(diǎn)：高亮度、高方向性、高單色性、高的相干性Highirradiance，Beamdivergence，

Monochromaticity，

Coherence1.1激光的特性①方向性：普通光源的發(fā)光無(wú)方向性，而激光的發(fā)光可以限制在幾個(gè)毫弧度立體角甚至更窄小的角度范圍，這就使得在照射方向上的照度提高了4

10(3×2)

107倍。②高亮度：激光之所以有強(qiáng)的破壞能力是由于其本征亮度(在光照射方向)，這是激光與物質(zhì)相互作用有非凡效果的決定因素。一般太陽(yáng)光亮度大約是：103W／(cm2·sr)，而大功率激光器的輸出亮度可達(dá)1010~1017W／(cm2·sr)，即是說(shuō)可以高出7-14個(gè)量級(jí)。③單色性：由激光輻射的能量，通常集中在十分窄的光譜波段或頻率范圍內(nèi)，一般實(shí)驗(yàn)室使用的光譜單色燈，單色性

／

106，而激光可高達(dá)1010~1013，因此利用現(xiàn)今已有的波長(zhǎng)可調(diào)的激光裝置可以做成波長(zhǎng)分辨率極高的單色儀，可用來(lái)測(cè)量在不同條件下產(chǎn)生原子和分子光譜的譜線寬度。④高相干性：激光不僅具有高方向性和高單色性的特點(diǎn)，由激光所產(chǎn)生的波列還有高度的整齊的間隔和長(zhǎng)度，這導(dǎo)致激光通過(guò)光學(xué)干涉儀的裝置，可以使波列前后，盡管有大的光程差，仍能相干涉。

激光的應(yīng)用需要的條件激光器必須滿足各種應(yīng)用的不同技術(shù)要求，必須高度穩(wěn)定可靠，價(jià)廉物美；有各種配套支撐技術(shù)，比如探測(cè)器、光學(xué)系統(tǒng)、精密機(jī)械、信號(hào)處理電路和電源等。

1、已發(fā)展成規(guī)模宏大的產(chǎn)業(yè)，如光纖通信和光存儲(chǔ)；2、已成為先進(jìn)的生產(chǎn)工具，如激光加工；

3、直接造福于人類健康，如激光醫(yī)療；

4、成為新型的武器裝備，如激光制導(dǎo)炸彈；5、探索和研究中的激光應(yīng)用

激光材料加工技術(shù)分類

CategoryofLaserMaterialProcessingTechnology激光切割LaserCutting激光焊接LaserWelding激光表面處理LaserSurfaceTreatment激光微加工LaserMicromaching激光快速成型LaserAssistedRapidPrototyping材料加工激光器

LasersforMaterialProcessingCarbonDioxideLasers-CO2Nd:YAGLasersDiodeLasersFiberLasersExcimerLasersThreeprimarylasingmechanismsforCO2laserdevicescurrentlyexist:1)conventional(sealedandslowflow);2)flowing(axialandtransverse);3)diffusion(noflowwiththecoolingwallsincloseproximity).

LasersforMaterialProcessing-CO2lasers快速軸流CO2激光器

快速軸流CO2激光器是由工作氣體沿放電管軸向流動(dòng)來(lái)實(shí)現(xiàn)冷卻的，且氣流方向同電場(chǎng)方向和激光方向一致，其氣流速度一般大于100m/s，有的甚至可達(dá)亞音速。其結(jié)構(gòu)主要由細(xì)放電管、諧振腔、高壓直流放電系統(tǒng)、高速風(fēng)機(jī)、熱交換器及氣流管道等部分組成。

特點(diǎn)：光束質(zhì)量好（基?；騎EM01模）

功率密度高

電光效率高，最高可達(dá)26%；

結(jié)構(gòu)緊湊

可以連續(xù)和雙制運(yùn)行

Typical6kWIndustrialCO2LaserLasersforMaterialProcessing-CO2lasers橫向流動(dòng)型CO2激光器

該激光器的工作氣體沿著與光軸垂直的方向快速流過(guò)放電區(qū)以維持腔內(nèi)有較低的氣體溫度，從而保證有高功率輸出。單位有效諧振腔長(zhǎng)度的輸出激光功率達(dá)10KW/m，商用器件的最大功率可達(dá)25KW/m。但其缺點(diǎn)是光束質(zhì)量較差，在好的情況下可以得到低階模輸出，否則為多模輸出。這種類型的激光器廣泛應(yīng)用于材料的表面改性加工領(lǐng)域，如激光表面淬火、激光表面合金化、激光表面熔覆、激光表面非晶化等。

9000W橫流CO2激光器（以色列）6000W橫流CO2激光器（德國(guó)）YAG激光器是以釔鋁石榴石晶體為基質(zhì)的一種固體激光器。釔鋁石榴石的化學(xué)式是Y3A15O12,簡(jiǎn)稱為YAG。在YAG基質(zhì)中摻入激活離子Nd3＋(約1%)就成為Nd:YAG。YAG激光器基本組成部分是激光工作物質(zhì)、泵浦源和諧振腔

YAG激光器按輸出波形可分為連續(xù)波YAG激光器、重頻YAG激光器和脈沖激光器；按工作波長(zhǎng)可分為1．06μmYAG激光器、倍頻YAG激光器、和可調(diào)諧YAG激光器等；按泵浦方式可分為：燈泵浦和半導(dǎo)體激光泵浦YAG激光Nd:YAGLaser2kWLampPumpedNd:YAGlaserLasersforMaterialProcessing-YAGlasersLasersforMaterialProcessing-YAGlasersTypical4kWIndustrialNd:YAGLaserLasersforMaterialProcessing-YAGlasersDiodelasersHighPowerDirectDiodeLasers[HPDDL],LasersforMaterialProcessing-DiodelasersLasersforMaterialProcessing-Diodelasers1、Crystal2、laserbeam3、outputmirror4、diodebar5、collimation6、rearmirror7、cooling8、supplyDiodepumpedYAGLaser(Sidepumped)DiodePumpedYAGLaser(Endpumpedlaser)LasersforMaterialProcessing-DiodepumpedYAGlasersThindiscpumpedLasersforMaterialProcessing-DiodepumpedYAGlasersDiagramofsinglemodulefordisclaserLasersforMaterialProcessing-DiodepumpedYAGlasersFiberLasersThefiberlaserisnotaNd:YAGlaserthatisfiberdelivered,butratheradiode-pumped,Ytterbium-basedfiberlaserresonatorthatisfiberdelivered.OnthewholethebeamqualityandpowerarebetterthanthecurrentNd:YAGlasertechnologythatisfiberdelivered.Nolaserthathasadvancedasfastasthefiberlaser.Withinafewyearsfiberlasershaveincreasedfromwattstokilowatts!Thetelecomtechnologyprovidedasoundtechnologyforrapidscalingtoindustrialpowerlevels.Theindustrialcommunityhasbenefitedfromthetelecomslowdown.Thenewdirectionofthetelecomtechnologyhasprovidedanewandexcitinglaserthatisbenefitinglasermaterialprocessing.LasersforMaterialProcessing-FiberlasersDiagramoffiberlaser;(CourtesyIPGPhotonics)LasersforMaterialProcessing-Fiberlasers4千瓦光纖激光60x80x160cm尺寸400kg重量300M長(zhǎng)(?=300mm)光纖傳輸光纖激光的靈活性三百米以上激光頭LasersforMaterialProcessing-FiberlasersLasersforMaterialProcessing-FiberlasersLasersforMaterialProcessing-FiberlasersYb鐿Er鉺Tm銩PotentialandRealityofIndustrialApplicationsforFiberLasersFiberlasersofferalargespectrumofcapabilitiesenablingittobeusedinmanydifferentapplications.Someoftheindustrialapplicationswithpromisingprocessingcapabilitiesinclude:?Lasermarking-“Q”switchedfiberlasersarebeingproducedwithupto200wattsofaveragepower?Medicaldevices-Singlemodepowerproducesprecisionsmallkerfcutting?Highspeedwelding-highmulti-kilowattpowerlevelswithgoodbeamqualityforTWBapplicationLasersforMaterialProcessing-Fiberlasers?Remotewelding-highbeamqualityenableslargeFnumberweldingcapabilitiesforbodyinwhite?Hydro-formtubecutting-flexiblefiberwithgoodbeamqualityprovidesfasterspeedwithquality?Thickplatewelding-multi-kilowattoperationprovidedeeppenetrationwelds?Precisionthinwelding-highspeedgalvooperationproduces“patternwelding”results?Sheetcutting-reliableflatsheetcuttingwithlowmaintenanceLasersforMaterialProcessing-Fiberlasers

IPG公司生產(chǎn)的2000瓦多模光纖激光器，在阿富汗成功執(zhí)行了掃雷任務(wù)，其在惡劣的環(huán)境下（高溫、震動(dòng)、灰塵）穩(wěn)定的表現(xiàn)得到美國(guó)軍方一致的贊揚(yáng)。"宙斯"激光掃雷系統(tǒng)從1986年開始使用了CO2、燈泵浦YAG、半導(dǎo)體泵浦YAG系統(tǒng)，最終選擇了穩(wěn)定、可靠性高、能耗極低的IPG光纖激光器。

在25-300米范圍內(nèi)平均30秒可以引爆一顆地雷。除了掃雷之外，還廣泛用于清除雷管、手榴彈、火箭筒、等三十多種武器。如果知道地雷的準(zhǔn)確位置，使用宙斯系統(tǒng)，可以在夜晚執(zhí)行任務(wù)，也可以引爆埋在地表之下的裝置。LaserCuttingLaserBeamQualityThebeamqualityofalaserdeterminesthefinalfocusedspotsizeofthelaserbeam.Thefinalfocusedspotsizedeterminestheenergydensityofthefocusedspot.Theenergydensitycombinedwiththepropertechniquedetermineswhattypeofmaterialprocessingisgoingtobeaccomplished.Thepowerofthelaser,beamqualityanddesignofthebeamdeliverysystemdeterminesmuchfortheprocess.AgoodqualityCO2laserbeamcanbefocusedtoaspotsizeontheorderof100micronsor0.004inches.Thisspotsizecoupledwith1kilowattoflaserpowercaneasilycutthinmaterialsincarbonsteelwhenusingoxygenassistgas.LaserCuttingLaserCuttingLasoxCuttingLasoxcuttingisaprocessfirstdevelopedbyBOCandisbeingdevelopedbyAlabamaLaserforcommercializationuseintheshipindustryandotherplatecuttingapplications.Lasoxhasdemonstratedcuttingmaterialtoseveralinchesinthickness.LaserCuttingFiberLaserCuttingTrialsThephotosbelowshowtheresultsofcuttingtrialswitha1.7kilowattIPGPhotonicsfiberlaser.Thelaserisdeliveredthrougha100micronfiber.Picture6showsthebeamdeliveryset-uponaroboticmotionsystem.TheheadusedisanALSUFOstyleheadwithacollimatorfocallengthof160mmandafocuslensof125mm.Picture7:

Fiberlasercutin1.1mmcarbonsteelhigh-pressurenitrogencut210mm/secat1.7kWLaserCuttingLaserCuttingLaserCuttingLaserCuttingLaserCutting光纖激光應(yīng)用于心血管支架的精密切割光纖激光應(yīng)用于心血管支架的精密切割光纖激光應(yīng)用于大型設(shè)備傳動(dòng)機(jī)構(gòu)的焊接LaserMicromachining-MedicalapplicationsFiberlasercuttingLaserWelding-FiberlaserweldingLaserWelding-PrecisionweldingThefollowingaresomemajorapplicationswherekilowattfiberlasersarereplacingbyCO2andYAGlasers:

Tailoredblankwelding

Remoteweldingofautomotivebodyinwhite

Transmissionwelding

Sintering

Heattreating

Pipewelding

Highspeedseamwelding

Hybridwelding

Sparkplugwelding

Weldingofshipstructuresbuilding

TitaniumweldinginaircraftLaserWeldingLaserWeldingHybridprocessingcombineseitherCO2orNd:YAGlaserbeamweldingwithvariousarcprocesses,includingplasmaarc,gastungstenarc,andgasmetalarcweldingLaserWelding-HybridweldingLaserWeldingLaserSurfaceTreatment-CladdingLaserSurfaceTreatmentLaserSurfaceTreatment-CladdingLaserSurfaceTreatment-CladdingLaserSurfaceTreatmentLaserSurfaceTreatment-Generating光纖激光應(yīng)用于金屬三維快速熔結(jié)成型系統(tǒng)使用IPG100W,CW,SM光纖激光器，精度為50umSLM技術(shù)制造的零件SLM制件橫截面組織CrosssectionofSLMproductSLM制件表面形貌SurfaceAppearanceofSLMproductLaserSinthering–200WSingleModeLaserSurfaceTreatmentLaserSurfaceTreatment-Engraving柔性印刷陶瓷網(wǎng)紋輥的激光雕刻

LaserSurfaceTreatment-Engraving柔性印刷陶瓷網(wǎng)紋輥的激光雕刻

LaserSurfaceTreatment-Engraving激光毛化LaserSurfaceTreatment-MarkingLaserSurfaceTreatment-MarkingLaserSurfaceTreatment-peelingLaser-processesinmicrotechnology

StructuringLaserdrilling(Ceramics,metals,polymers) Nd:YAG-Lasers,Excimer-LasersLasermicroablation(Microtooling,microrapidprototyping) Excimer-Lasers,freq.conv.Nd:YAG-LasersLasersurfacemodification Excimer-LasersPackagingLasersoldering(PCBs,Connectors) cw-DiodelasersLaserwelding(Micromechanicalparts,polymerparts) Nd:YAG-Lasers,Fiber-Lasers,diodelasersLaserbonding(Silicon-Glass-Compounds) cw-Nd:YAG-LasersLaserMicromachiningLaserSelectiveSolderingSystemLaserSolderSystemisaòTurnKeySolutionsóforsolderingextremelydifficultsoldersitessuchasverysmallcomponents,assembliesrequiringhighlylocalizedheating,brazingandweldingapplications.LaserMicromachining-selectivesolderingLaserMicromachining-selectivesolderingLaserSolderBallJetSystem-SB2-JetTheSB2-Jetsolderballsystemistheidealsolutionforflexiblesolderballplacementandreflow.Ataspeedof10ballspersecond,itisoneofthefastestmachinesonthemarkettoday.ItprovidesareproduciblesolderbumpingtechnologyforthepackagingLaserMicromachining-SB2SolderballTSAFPCsolderbumpSolderballLasertomeltsolderball(SolderBallsize:?0.3mm)SolderballdropontotoTSApad,filltheTSAkey-holeandjointwithFpcsolderbump;N2preventoxygenatingduringthewholesolderjetprocess.LaserMicromachining-SB2Visual:TSAkey-holeshouldbefilledwithsolder;2placesofTSAkey-holeshouldbecoveredwithsoldercompletely;Notraceburnareallowed.Peelstrength:Thepeelstrengthshouldbemorethan30gaccordingtothemanualsoldering.LaserMicromachining-SB2SB2-ApplicationsLaserMicromachining-SB2LaserweldingofleadframesLaserbeamweldingofpassiveheatsinksonstampedleadframesNd:YAG-LaserP=3kWWeldingtimet=5msWeldinggeometry<200μmLaserMicromachining-HybridmicropartsPolymerweldingofsensitiveelektronicsandmicropartsApplications:SensorsVentilsLockingsystemsMicrofluidiccomponentsMedicalproductsManufacturingdevice:DiodelaserP=5-50Wserialprocessing

v>1m/minSimultaneousprocessingt<1sLaserMicromachining-JoiningofPolymerParts

DiodePumped,repetitivelyq-switchedUV:YAGLaserOperatingmode:TEM00(gaussianpowerdistributionacrossthebeam)

Wavelength:355nm(UV)

Peakpower@3kHz:above15kwPulsewidth@3kHz:30ns(typical)Pulsestability@3kHz:7%ProgrammablePulseRate:0–20kHzLaserbeampositioning:cross-axiswithgalvanometerLaserbeamresolution:<0.00004"(1mm)Beampositionaccuracy:±0.0008"(±20mm)Fieldsize:21"by25"Max.speed:20,000viasperminuteProducingbothblindviasandthroughviasDrillingonCopperandallPCBdielectricmaterialEliminatingtheneedforpre-etchingESIModel5200LaserDrillingSystemLaserMicromachining-PCB

IMPACT2500LASERGENERATORTEA-CO2LaserWavelength:9300nmAverageOutputpower:65W(max)Pulseenergy:130mJ/cm2(max)Poweratprocessingpoint(f3.6mmmasksize):>1.64Wat50Hzpulsefrequency

Pulseenergydensity:100mJ/cm2

Pulsefrequency:500Hz(max)Beamsize:9±1x8±1mm(30mmfarfromfrontoptics)Laserbeampositioning:cross-axiswithgalvanosystemX-YTablePositionaccuracy:±5mm(±2mmrepeated)GalvanosystemScanarea:5mmx40mmPositionaccuracy:±20mm

AutoMaskchangerNumbersofpatterns:13(f0.75-f3.60)Auto-alignment(imageprocessing)CCDcamera:2unitsFieldofvision:3.2x2.4mmSearchaccuracy:±10m