简介：AcompositetransparentYAG/Yb:YAG/YAGceramicwaspreparedbyanon-aqueoustape-castingmethod.Anopticaltransmittanceof82%wasobtainedatvisiblewavelengthandaround1100nm.Alow-threshold,broadbandtunablecontinuous-wave(CW)laserat1031nmwasfurtherdemonstratedfromtheceramicsample,whichwaspumpedbya974nmfiber-pigtailedlaserdiode.Thethresholdpumppowerwas0.45Wandthemaximumoutputpowerwas3.2W,correspondingtoaslopeefficiencyof20.4%.ByinsertinganSF57prisminthelasercavity,theoutputwavelengthcouldbetunedcontinuouslyfrom1021to1058nm.

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简介：Thehighrepetitionrate10J/10nsYb:YAGlasersystemanditskeytechniquesarereported.Theamplifiersinthissystemhaveamulti-passV-shapestructureandtheheatintheamplifiersisremovedbymeansoflaminarwaterflow.Inthemainamplifier,thelaserisfour-pass,andanapproximately8.5J/1Hz/10nsoutputisachievedintheprimarytest.Thefar-fieldoftheoutputbeamisapproximately10timesthediffractionlimit.Becauseofthehigherlevelsofamplifiedspontaneousemission(ASE)inthemainamplifier,theoutputenergyislowerthanexpected.Attheendwediscusssomemeasuresthatcanimprovethepropertiesofthelasersystem.

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简介：Adiode-pumpedmasteroscillatorpoweramplifiersystembasedonacryogenicYb:YAGactive-mirrorlaserhasbeendeveloped.Theperformancesofthelaseramplifieratlowtemperatureandroomtemperaturehavebeeninvestigatedtheoreticallyandexperimentally.Amaximumoutputenergyof3.05Jwithanoptical-to-opticalefficiencyof14.7%hasbeenachievedbyusingthemasteramplifiersystem.

简介：从光学谐振腔阈值条件的推导出发,利用光学薄膜设计软件Filmstar为谐振腔的左右腔镜各设计了两种光学薄膜,使1030.5nm-1055.5nm波段连续可调谐的Yb：YAG激光器实现了工作状态的最优化.针对左右腔镜,对设计方案所得结果进行了比较,并分析了方案的可行性.结果表明,左腔镜两设计方案与优化目标的差距均小于1.15%;右腔镜两设计方案与优化目标的差距均小于0.05%,本文设计为激光器谐振腔的腔镜镀膜提供了可靠的理论依据.

简介：Weproposeageneralmethodologytodefinetheoptimumdopingionvolumedistributionrequiredforanefficientsolid-statelaseramplifier.ThisapproachisillustratedinthecontextoftwoexperimentaldiodepumpedYb:YAGamplifiersoperatingat300and160K.Processingofsuchtailoredgainmediaisnowpossiblethroughhorizontaldirectcrystallization.

简介：l、关键技术参数或产品性能YAG透明陶瓷材料采用强场熔铸制造的工艺技术制备而成。产品性能：0380×3～8mm，透明YAG陶瓷样品在可见光波段的透过率≥75％。2、功能及主要应用情况激光透明陶瓷是国际材料界研发的热点领域，在我国，这类材料主要应用于国家重大需求，即激光聚变点火工程和透明陶瓷装甲、大飞机工程、以及航天工程等。

简介：Anewmethodfordeterminingthepartialmeltingdepthofmantle-derivedmagmaandlithosphericthicknessincontinentalregionsisderivedfromREEgeochemistry.ThiseffectivetechniqueusesvariationsintheCe/YbandSm/YbratiosfoundinmainlyvolcanicrocksincontinentalChina.TheratioschangewiththedepthoforiginconsistentwiththecorrelationbetweenlithosphericthicknessandtheCe/YbandSm/Ybratiosfoundinoceanicbasalt.Theseratiosincreaseexponentiallywiththedepthoforigin,thelithosphericthickness,ofawidevarietyofCenozoicvolcanicbasaltandPaleozoickimberliteintheNorthChinaCraton,northeasternChinacontinentandvicinity.Thisfunctionalrelationshipwithdepthisshowninaplotoftheratiosthatformsaconcordiacurve,whichiscloselyexpressedbyformulasusing8-degreepolynomials.Theseprovideamoreaccurategageinmeasuringthelithosphericthicknessthanthetraditionalgeophysicalmethods.Whenappliedtovolcanicrockofdifferentagesitalsorevealshowthethicknesshaschangedovertimeandthus,greatlyaidstheunderstandingofthetectonichistory.RelationsbetweentheCO2content,mineralreactionsandpressureintheupperasthenospherebeneaththebaseofthelithosphereappearstoaffecttheproportionsofREEinpartialmeltsandbringsaboutaclosecorrelationbetweenlithosphericthicknessandtheCe/YbandSm/Ybratiosinmantle-derivedmagmaticrock.Thisthicknessgauge,forbothcontinentalandoceaniclithosphere,providesanewapproachinanalyzingthelithosphericthicknessindifferenttectonicsettingsandgeologictimes.

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简介：Inthispaper,Er/Ybco-dopedfiberamplifiers(EYDFAs)withanYb-bandfiberBragggrating(FBG)atthepumpendtoimprovetheperformanceoftheamplifierissystematicallystudied.TheinfluenceofthereflectivityandcenterwavelengthoftheFBGalongwiththegain-fiberlengthontheperformanceofanEYDFAarenumericallyanalyzed.TheresultsshowthatthewavelengthoftheFBGhascriticalinfluenceontheefficiencyoftheEYDFA,whereastherequirementtoitsreflectivityisrelaxed.Itisaneffectiveandpromisingwaytoimprovetheefficiencyofahigh-powerpumpedEYDFAbyintroducingasuitableYb-bandFBGatthepumpend.Basedontheanalysisoftheunderlyingprinciples,suggestionsforthepracticaldesignandpossiblefurtherimprovementstrategiesarealsoproposed.

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简介：目的：观察倍频Nd：YAG激光联合YAG激光行周边虹膜切除术治疗急性闭角型青光眼的疗效及并发症。方法：本组共105例，其中临床前期91眼，先兆期32眼，间歇期46眼，均先使用倍频Nd：YAG激光在拟行周边虹膜切孔处分层射击，最后用YAG激光穿透造孔，随访12mo，观察疗效及并发症。结果：术后1～6h眼压暂时性升高，24h后眼压下降，虹膜周切孔均通畅，房角无粘连，3眼周切孔处局限性晶状体混浊。结论：倍频Nd：YAG激光联合YAC激光行周边虹膜切除术是防止闭角型青光眼急性发作的安全有效的手术。

简介：TransparentYAG(yttriumaluminumgarnet)ceramicswerefabricatedbysolid-statereactionmethod.Effectofadditive(tetraethylorthosilicate,TEOS)onmicrostructureofYAGceramicswasinvestigated.IftheadditionofTEOSismorethan3%(massfraction),largeamountofliquidphasecanbeyieldedatgrainboundaries,resultingintheformationofsecondphaseparticlesatgrainboundaries.Iftheadditionislessthan0.05%(massfraction),poresareentrappedinthegrains.Thesuitableamountis0.5%(massfraction).AfullytransparentYAGceramicwasfabricatedbyvacuumsinteringat1700℃for5h.OpticaltransmittanceoftheYAGceramicis63%inthevisiblelightwavelengthsand70%intheinfraredwavelengths.

简介：YAGlaserweldingwithsurfaceactivatingfluxhasbeeninvestigated,andtheinfluencingfactorsandmechanismarediscussed.TheresultsshowthatbothsurfaceactivatingfluxandsurfaceactiveelementShavefantasticeffectsontheYAGlaserweldshape,thatistoobviouslyincreasetheweldpenetrationandD/Wratioinvariousweldingconditions.Themechanismisthoughttobethechangeofweldpoolsurfacetensiontemperaturecoefficient,thus,thechangeoffluidflowpatterninweldpoolduetotheflux.

简介：Anewthulium-dopedyttrium-aluminium-garnet(YAG)crystalwithvariedconcentrationsofTmwasgrownbyAnhuiInstituteofOpticsandFineMechan-ics,AcademiaSinica.Owingtoitssuperadvantagesofawiderangeoffrequenciesandhighefficience,thegarnetisconsideredtobeaneffectivetunableinfraredlasercrystalandmeetstherequirementsofcoherent

简介：Yttriumaluminumgarnet(YAG)transparentceramicswerefabricatedbysinteringatoxygenatmosphere.Tetraethylorthosilicate(TEOS)wasaddedasthesinteringadditivetocontrolthegraingrowthanddensification.Poreswereeliminatedclearlyattemperaturelowerthan1700oC,whilegrainsizewasaround3μm.Thein-linetransmittancewas80%at1064nmwhensamplesweresinteredat1710oC.TheeffectofTEOSwasstudiedinoxygenatmospheresinteringforNd:YAGtransparentceramics.Athighertemperaturelike1710oC,thegraingrowthmechanismwassolutedrag,whileat1630and1550oCthegraingrowthwascontrolledbyliquidphasesinteringmechanism.And0.5wt.%TEOSwasthebestaddingcontentforNd:YAGsinteredinoxygenatmosphere.

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简介：AIM:Toinvestigatetheeffectsofanewopeningpatterninneodymium:yttrium-aluminum-garnet(Nd:YAG)laserposteriorcapsulotomyonvisualfunction.METHODS:Thistechniquewasconductedalongacircularpattern.Theenergyrangedbetween0.8and1.2mJ/pulsewasconsumedandmeantotalenergylevelswere74±21mJ(mean±standarddeviation:SD,from40to167)andlasershotsaimedat150μmawaybehindadatumpointandwentalonganimaginarylinewhichextends0.5mminsidefromopticmarginandintothecircularenblocpattern.Vitreousstandswereattachedwithfragmentandthentheywerecutoffbythelaseraftercircularapplication.Thecircularfragmentwascompletelyseparatedfromvitreous,andthenthisfragmentwasquicklysunkinintravitrealspace.RESULTS:Thefollow-upperiodrangesfromatleastaweekto40mo,making15.8moonaverage.Theproceduraloutcomeshowed96%(74eyesoutofthe77eyes)enhancementinpatients’visualacuity.Cystoidmacularedemaorretinaldetachmentwasnotobservedinanyofthepatientsduringfollow-upperiods.CONCLUSION:Thisnewtechniqueisexpectedtoimprovetheweaknessesthattheconventionalprocedureshavebyaddingtheprocesstocutoffvitreousstandsattachedwiththefragmentbythelasertothecircularapplication.