简介：Wereportsingle-shotdamagethresholdasafunctionofpulseduration(50-900fs)forMgF2/ZnS800-nmomnidirectional-reflectionfilm,interferencefilter,andgoldfilm.Theresultsindicatethatthedamagewithultrashortpulseisnonthermal,whichisdifferentfromthatwithlongpulse.Additionally,theablationcraterdepthsof45°high-reflectionfilmandinterferencefilterarepresented.Alogarithmicrelationbetweentheablationdepthandpulsefluence,whichissimilartothatoftransparentmaterials,isfound.

简介：Usingmoleculardynamics(MD)methodscombiningwithtwo-stepradiationheatingmodel,themechanismsofablationandthethermodynamicstatesatNisurfaceunderfemtosecondlaserirradiationareinvestigated.Simulationresultsshowthatthemainmechanismsofablationareevaporationandtensilestressesgeneratedinsidethetarget.Thevelocityofstresswaveispredictedtobenearlyequaltosoundvelocity.Theratesofablationatdifferentfluencesobtainedfromsimulationsareingoodagreementwithexperimentaldata.Superheatingphenomenonisalsodiscovered.

简介：Aliquid-nitrogen-cooledTm,Ho:YLFlaserisconstructedwitha10-mm-longTm(6%)andHo(0.5%)co-dopedyttriumlithiumfluoridecrystalpumpedbyalaserdiodeoperatingat792nm.ThelaseroutputpowerisimprovedbycoolingtheTm,Ho:YLFcrystalfrom300to77K.Whenthecrystaliskeptat77K,thelaserthresholdpumppoweris230mW,theslopeefficiencyis27.4%,andthemaximumoptical-to-opticalefficiencyis19.9%.Atthesametime,therelationbetweentheinputpowerandtheoutputpoweratdifferenttemperaturesisobtained.

简介：Inordertodeterminetheappropriatetreatmentinterval,267patientswhounderwent3sessionsoftreatmentwithQ-switchedalexandritelaserweredividedinto4groupsaccordingtotreatmentinterval,andtheirclinicalresponseswerecompared.Amongthem,187wereaskedabouttheprocessofpigmentfading.Moreover,lightandtransmissionelectronmicroscopywereperformed.Itwasnotedthattheclinicalresponseofthe5-6monthintervalgroupwassignificantlybetterthanthatofthe3-4monthgroup,butshowednosignificantdifferencefromthatofthe7-8or≥9monthgroup.80.21%ofinvestigatedpatientsstatedthatmarkedpigmentfadingcouldnolongerbeobserved7monthsafterirradiation.4monthsafterirradiation,thedegeneratedmelanosomesandcelldebriswerestillscatteredamongcollagenfibers,scavengedgraduallybymacrophage.Inconclusion,anappropriatetreatmentintervalis5-6months.

简介：Asimplifiedringcavityforachievingaunidirectionalroomtemperaturemulti-wavelengtherbium-dopedfiberringlaserwithoutopticalisolatorisdemonstrated.ThefiberringcavityisbuiltinsuchawaythattheopticalfieldspropagatingintwodirectionssufferdifferentlossescausedbyonesampledfiberBragggrating.Furthermore,simultaneousmulti-wavelengthlasingwith0.8-nmintervalsisdemonstratedwithsinusoidalphasemodulationjustbeforethesampledfiberBragggratingtopreventsingle-wavelengthlasingandunstablewavelengthoscillation.

简介：Awavelengthtunable,highrepetitionratemode-lockedfiberringlaserwasdemonstrated.Intheexperiment,photoniccrystalfiber(PCF)isusedasanintracavitycompressionmedium.ThehighnonlinearityandanomalousdispersionofPCFcancauseintracavitycompressionandresultinsignificantreductioninthepulsewidth.Thepulsesdurationattherepetitionrateof9.99GHzwaslessthan10psovertherangeof1532-1565nm.

简介：ApassivelyQ-switchedNd3+:YAGlaserwithcornercubeistheoreticallyandexperimentallystudied.Weanalyzethepolarizationvariationincavityandsimulatethepeakpower,pulseenergyandpulsewidthchangedwiththerotationangleofcornercubenumerically.Anexperimentismadetoverifythetheoreticalresults.Withrotatingtheangleofcornercubeabouttheaxisthevariationrangeofpeakpoweris1.77MW(from10.36to8.59MW),andthatofpulseenergyis14.9mJ(from159.5to174.4mJ),thefluctuationofpulsewidthis2.95ns.Theexperimentalresultsagreewiththetheoreticalanalysistotheextentofvariationrules.Themostdynamictostaticenergyratioof62.5%isachieved.

简介：Inapracticalcouplingsystem,acylindricalmicrolensisusedtocollimatetheemissionofahighpowerlaserdiode(LD)inthedimensionperpendiculartothejunctionplane.Usingpassivealignment,theLDisplacedinthefocusofthecylindricalmicrolensgenerally,regardlessoftheperformanceofthemultimodeopticalfiberandtheLD.Inthispaper,amorecompleteanalysisisarrivedatbyray-tracingtechnique,bywhichtheangleθoftherayafterrefractioniscomputedasafunctionoftheangleθooftheraybeforerefraction.ThefocusofthecylindricalmicrolensisnotalwaystheoptimalpositionoftheLD.Infact,inordertoachieveahighercouplingefficiency,theoptimaldistancefromtheLDtothecylindricalmicrolensisdependentonnotonlytheradiusRandtheindexofrefractionnofthecylindricalmicrolens,butalsothedivergenceangleoftheLDinthedimensionperpendiculartothejunctionplaneandthenumericalaperture(NA)ofthemultimodeopticalfiber.Theresultsofthisdiscussionareingoodagreementwithexperimentalresults.

简介：HighorderBraggscattering(M=2andM=3)operationsofthedistributedfeedbackdyedopedsol-gelsilicalasersareachievedusingthesecondharmonicoutputofaNd:YAGlaserasthepump.Laserlinewidthoflessthan0.06nmandconversionefficiencyof0.7%forM=3and11%forM=2aremeasured.Wavelengthtuningofabout15nmaroundtheemissioncenterhasbeenrealizedbyvaryingtheintersectionangle.

简介：Anewwavelengthbeamcombiningtechniqueforahigh-powerlaserdiodebarbyusingatemperaturegradientheatsinkhasbeenproposed.Thethermalcontrollingprincipleofthetemperatureheatsinkhasbeendiscussed.Ithasbeenprovedbyexperimentthatthelineartemperaturedistribution,whichgenerateslinearwavelengthspreadoftheoutputbeamsfromaLDbar,canbeobtainedbyintroducingatemperaturegradientheatsinkandtheoutputbeamscanbefocusedintoarelativesmallspotbyusingtheCzerny-Turnerbeamshapingsystem.

简介：Theopticalpropertiesofafive-levelatomicsystemcomposedofaA-typefour-levelatomicandatripodfour-levelatomicsystemsareinvestigated.Itisfoundthatthebehaviorsofelectromagneticallyinducedtransparency(EIT)andgroupvelocitycanbecontrolledbychoosingappropriateparameterswiththeinteractingdarkresonances.Inparticular,whenallthefieldsareonresonance,theslowlightatthesymmetrictransparencywindowswithamuchbroaderEITwidthisobtainedbytuningtheintensityofthecouplingfieldincomparisonwithitssub-system,whichprovidespotentialapplicationsinquantumstorageandretrievaloflight.

简介：Becausepulserepetitionrateaffecteddirectlythemomentumcouplingcoefficientoftransverselyexcitedatmospheric(TEA)CO2laserpropulsion,adoublepulsetrigger,controllinghighvoltageswitchoflaserexcitationcircuit,wasdesigned.Thepulseintervalrangedbetween5and100ms.Themomentumcouplingcoefficientforair-breathingmodelaserpropulsionwasstudiedexperimentally.Itwasfoundthatthemomentumcouplingcoefficientdecreasedwiththepulserepetitionrateincreasing.

简介：Influenceofthermal-mechanicalpropertiesonthefeaturesofthepandapolarization-maintainingopticalfiber(PMF)infabricationprocessisstudiedindetailbyfiniteelementmethod(FEM).Thestressbirefringenceis2.13443×10-4obtainedbythestaticanalysisand2.1269×10-4bydynamicanalysis.Thedifferenceinsimulationbytwomethodsisaround0.4%.Thenon-uniformityofstressbirefringenceinthefibercoreisabout1.6%.Predictedresultsdemonstratethateffectofthethermalconductiveparameteronfiberthermalstressdominates.Thehighanduniformstressbirefringenceinthefibercoreisobtainedbyappropriatelyselectingsuitablestressregionareaandposition.

简介：Anopticallyactivatedopticalswitchbasedonsuppressionofmodeinterference(SMI)ispresented.Theimagingpropertiesofmulti-modeinterference(MMI)sectionintheswitchwithY-branchcanbemodifiedbyacontrollinglightinjection.Theswitchwassimulatedbyfinitedifferencebeampropagationmethod(FD-BPM)andfabricatedonGaAlAs/GaAsepitaxialmaterials.Atthewavelengthof1.31μm,theprimaryexperimentshowedanextinctionratioofabout8dBwithcontrollinglightpowerdensityof73.5W/mm2.

简介：Acoupleofsimple-structurephasemodulatorswereusedinactivemode-lockedfiberlasertoimplementrepetitionratecontinuoustuning.Thelaserproducespulseasshortas5.7pswhoserepetitionratetuningcancoverthespacingoftheadjoiningordermode-lockingfrequencies.

简介：TheenhancementofstimulatedRamanscattering(SRS)ofacetone(C3H6O)andthegenerationofthreecolorlasersinlasingdyerhodamineB(RB)werereported.Thefirst-orderStokeswave(629.9nm)ofSRSofC3H6Owasamplifiedby2.83timesthanthatofpureCsH6O.Atthesametime,adyelaserofRBatthewavelengthfrom575to598nmcanbegeneratedinasuitableconcentrationofRBbetween3×10-5and2×10-4mol/L.Thusthegreenpumplaser,yellowdyelaser,andredStokeswaveconcurred.

简介：Diode-pumpedpassivelyQ-switchedNd:GdVO4/Cr4+:YAGlaserswithasimpleflat-flatcavityweredemonstrated.Themaximumaverageoutputpowerat1.06μmwas1.25W.Thehighestpeakpowerandpulseenergywere7.56kWand75μJ,respectively,withthepulserepetitionrateof11.1kHzandpulsewidthof10nsattheincidentpumppowerof8W.

简介：Theeffectsofvacuum-inducedcoherence(VIC)onthepropertiesoftheabsorptionandgainoftheprobefieldinanequispacedthree-levelladderatomicsystemareinvestigated.Itisfoundthatlasingwithoutinversion(LWI)isremarkablyenhancedduetotheeffectofVICinthecaseofthesmallincoherentpumprate.

简介：Anoptimizeddesignoflaserrangefindingsystemusingtheself-mixingeffectinasingle-modevertical-cavitysurface-emittinglaser(VCSEL)isproposed.Inordertoimprovetherangingaccuracyandexpanddynamicmeasurementrange,weapplydifferencefrequencyanalogphase-lockedloop(PLL)insteadoffastFouriertransform(FFT)toprocesssignal,andchoosetheoptimumtriangularwavefrequencyfm=500Hzandsmallmodulationcurrent△Ip-p=0.28mAtomodulatesingle-modeVCSEL.Theexperimentresultsshowthat,withoutcontrollingthelaser'stemperature,therangingaccuracyisbetterthan2mmandthemeasurementdynamicrangeisaslargeas50-500mmwhenthesamplingtimeis0,1sandtheroomtemperatureis0-55℃.

简介：Thispaperreportsahighpower,all-solid-state,quasi-continuous-wavetunableTi:sapphirelasersystempumpedbylaserdiode(LD)pumpedfrequency-doubledNd:YAGlaser.Themaximumtunedoutputpowerof4.2W(797nm)andtunedaveragepowerof3.7WwereachievedwhenfixingtheTi:sapphirebroadbandoutputpowerat5.0Wandapplying750-850nmbroadbandcoatedmirror.