简介：ACe3+tion-dopedα-NaYF4singlecrystalofhighqualityisgrownsuccessfullybyanimprovedfluxBridgmanmethodundertheconditionsoftakingthechemicalrawcompositionofNaF:KF:YF3:CeF3inthemolarratioof30∶18∶48∶4,wheretheKFisshowntobeaneffectiveassistantflux.Thexraydiffraction,absorptionspectra,excitationspectra,andemissionspectraoftheCe3+t-dopedα-NaYF4singlecrystalaremeasuredtoinvestigatethephaseandopticalpropertiesofthesinglecrystals.TheabsorptionspectrumoftheCe3+t:α-NaYF4showsastrongbandthatpeaksatthewavelengthof300nm.TheemissionspectrumoftheCe3+t:α-NaYF4emitsanintenseultraviolet（UV）bandatthewavelengthof332nmundertheexcitationof300nmlight.Twoseparatedluminousbandsof330and350nm,whichcorrespondtothetransitions5d→2F25∕2and5d→F7∕2,canbeobtainedbyGaussfitting.ThestrongemissionintensityattheUVbandandtheexcellentopticaltransmissionintherangeofUVwavelengthsindicatethatCe3+t:α-NaYF4singlecrystalscanbeconsideredasapromisingmaterialforUVlasers.

简介：Ablationdynamicsoftungstenirradiatedwitha70fslaserpulseisinvestigatedwithX-rayinterferometryandX-rayimagingusinga13.9nmsoftX-raylaserof7pspulseduration.Theevolutionofhigh-densityablationfrontoftungsten(i.e.,W)ispresented.Theablationfrontexpandsto～120nmabovetheoriginaltargetsurfaceat160psafterfemtosecond-laserirradiationwithanexpansionspeedofapproximately750m∕s.TheseresultswillprovideimportantdataforunderstandingablationpropertiesofW,whichisacandidatematerialofthefirstwallofmagneticconfinementfusionreactors.

简介：Thevisibleandnear-UVemissionspectroscopyofmethane(CH4)inducedbyafemtosecondintenselaserfield(800nm,40fs,1014W∕cm2)isstudied.BymeasuringthedecayprofilesoftheneutralfragmentproductCH(A2Δ→X2Π),tworeactionpathways,i.e.,theelectron-ionrecombinationthroughe-tCHt4andthedirectdisintegrationofCHt4arefoundtoberesponsibleforpopulatingtheelectronicexcitedstatesoftheneutralfragmentproductCH,whichgivesrisetothephotoemissions.Ourresultsprovidecomplementaryinformationonpreviousunderstandingofthestrong-field-inducedphotoemissionmechanismofCH4throughneutraldissociationofsuperexcitedstates.

简介：WereportamonolithicTm:YLFmicrolaserinthisLetter.Inordertoimprovetherelaxationoscillationofthelaser,bothendsofthecrystalarecoated,makingtheTm:YLFcrystalitselfaresonantcavity.Themicrolaserispumpedbya792nmlaserdiodeoperatedinthecontinuouswave(CW)mode.Weobtainmaximumoutputpowersof7.78and10.4Watthetotalincidentpowerof43.6Wwithfocuslensesof37.5and40mm,respectively,correspondingtotheslopeefficienciesof25.6%and40.0%andtheoptical–opticalconversionefficienciesof17.8%and23.8%.Itisclearthattheamplitudeoftherelaxationoscillationissmallerandthebeamqualityisbetterwiththefocuslengthof37.5mm;however,thelaserwiththefocuslengthof40mmproducesahigheroutputpowerandamorestablewavelengthcenteringat1878.44nm.

简介：Apulsedcurrentisintroducedintothetraditionalcoaxiallasercladdingprocesstodecreasetheporosityofthecladdinglayer.Themagnetocontractionforcecausedbypulsedcurrentexertedonthemoltenpoolsqueezesthegasoutandcompensatestheshrinkageduringmoltenpoolsolidification.Asaresulttheporosityofthecladdinglayerisdecreasedtoanextremelylowdegree.Simultaneously,thegrainofthecladdinglayerisfinerwiththeaddedsupercoolingdegreewithpulsedcurrent.Themicrohardnessofanequiaxedzoneinthecrosssectionofacladdinglayeralsoincreases.

简介：Theirradiationofcellscombinedwiththeimmunoconjugateofgoldnanoparticlesbytheshortpulselasercanmaketheplasmamembranebetransientlypermeabilized,whichcanbeusedtotransferexogenousmoleculesintothecells.Weexplorethistechniqueasanovelgenetransfectionmethodforfloatingcells.Threedifferentfloatingcellsexposedtothelaserareselectivelytransfectedwithfiuoresceinisothiocyanatedextran,antibody,andgreenfluorescentprotein(GFP)codingplasmids,andtheviabilityofcellsaredeterminedbypropidiumiodide.Forfluoresceinisothiocyanate-dextran,thebesttransfectionefficiencyof65%isobtained;fortheantibody,itis74%;whereasforthegreenfluorescentproteincodingplasmids,averysmalltransfectionefficiencyisgained.Ifthetransfectionefficiencyisimproved,goldnanoparticleswillbeveryusefulasmediatorforgenetransfectioninlivingcells.

简介：Acompactmultipasscellwithlowfringesandhighthermalstabilityisdescribed.Thiscellisformedbytwotwistedcylindricalmirrors.Theopticalparametersaredeterminedbasedontheselectioncriteria,whichincludemirrorfillingefficiency,interferencefringes,andpatternstability.Withapatternof174passes,thiscellgivesa22-mpathlengthinavolumeof0.55L.Theresultsofanabsorptionmeasurementofoxygenat13091.7cm1showthatthefringenoiseislowerthan6.54×104.Themaximumallowedtemperaturechangetokeepthebeamfromexitingis33K,whichindicateshighstabilityagainstthermaldrift.

简介：Siliconnanoconearrayswithmetalsilicide(FeandCr)-enrichedapexesarefabricatedonSi(100)substratebytheAr+ionbombardmentmethod.Thenanoconearraysshowexcellentfieldemissionproperties.Ahighcurrentdensity(J)of～0.33mA/cm2underafieldof～3V/μm,averylowturn-onfieldof～1.4V/μm,andaverylargeenhancementfactorof～9466arealsoobtained.TheemissionJofSinanoconearraysremainsextremelystableforlongperiodsoftime(24h).

简介：1SignificanceofAllSolidStateLaser(DPL)TechnologyinFieldofLaserBecauseoftheadvantagesofhighconversionefficiency,goodbeamquality,smallsizeandlightweight,DPLbecomesthehotspotandpriorityofdevelopmentoflasertechnology.Itmaybethemainbodyoflaserinthefutureandreplacegaslaserandliquidlaser.Itisagreatrevolutionoflasertechnology.ThedevelopedcountriesvieindevelopingDPL.Chinahasachievedgreatsuccessinthisfield,butthereisawidegapbetweenthedevelopedcountriesandus.Weshouldattachgreatimportancetoit.

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

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

简介：ApyrotechnicallypumpedNdglasslaserisdemonstratedbytheuseofpyrotechnicflashlampscomposedofseveralchemicalmaterialsarrangedinastableplaneconcaveresonatorcavity.Theflashlampwasmadeofchemicalmixturewithoxidant,fuel,andbinder.TheemissionspectrumofpyrotechnicflamecoveredmostoftheabsorptionbandsofNd~(3+)inphosphateglass.Under4.56-gchemicalmixturepumping,longpulseoutputpowerofabout5.5Wwasachieved.

简介：Toobtainhighpower589-nmyellowlaser,aT-shapedthermal-insensitivecavityisdesigned.Theoptimalpowerratioof1064-and1319-nmbeamsisconsideredandthefundamentalspotsizedistributionfromtheoutputmirrortothetwolaserrodsarecalculatedandsimulated,respectively.Asaresult,a589-nmyellowlaserwiththeaverageoutputpowerof5.7Wisobtainedintheexperimentwhenthetotalpumpingpoweris695W.Theoptical-to-opticalconversionefficiencyfromthefundamentalwavestothesumfrequencygenerationisabout15.2%andthepulsewidthis150nsattherepetitionrateof18kHz.Theinstabilityoftheyellowlaserisalsomeasured,whichislessthan2%within3h.ThebeamqualityfactorsareM_x~2=4.96andM_v~2=5.08.

简介：WepresentaHerriott-typemultipasslaserabsorptionspectrometerenhancedbyopticalheterodynedetection.Theproposalisdemonstratedbymeasuringthespectraofwatervapormoleculeintheregionfrom12247.6873to12249.6954cm-1.Comparedwithdirectabsorptionspectroscopy,thesignal-to-noiseratioisimprovednearlyonemagnitudeoffactorbycombiningwiththeopticalheterodynespectroscopyandextraweakabsorptionlinesareobserved.Theminimumdetectableabsorptionisestimatedat4.36×10-8cm-1andthemeasuredlineshapedominatedbyDopplerbroadeningcanbepreciselyrecoveredbydirecttransformationofexperimentalopticalheterodynespectralprofile.

简介：Thetime-of-flightmassspectrum(TOFMS)relativetotheresonanttwo-photonionizationofgasphasep-dichlorobenzenewasobtainedinthewavelengthrangeof240-250nmbyahome-madesystem.Aspecialdesignwasmadetoreducetheeffectofmemoryontheinnerwallofthesampleinletsystemsuitablefortheinvestigationofsemi-volatileorganiccompound.Inthiswavelengthrange,p-dichlorobenzenemoleculesfirstlyabsorbedonephotontobeexcitedfromthegToundstate~1A_g(S_0)tothefirstexcitedstate1B2u($1),thenabsorbedanotherphotontobeionized.Therelationshipbetweenthesignalintensityofp-dichlorobenzenemolecularionC_6H_4~(35)Cl_2~+at248-nmwavelengthandthelaserpowerwasgiven.The1.52powerindexofC_6H_4~(35)Cl_2~+wasatypicalidentificationofthe3/2powerlaw.TherelationshipbetweentheionsignalintensityofC_6H_4~(35)Cl_2~+andthesampleconcentrationwasclosetoalinearoneintheppm(V/V)range,whichledtoadetectionlimitof125ppb(V/V)forp-dichlorobenzene.

简介：

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：Weproposethatdomaininversioncanbedirectlyinducedbyfemtosecondlaserboththeoreticallyandexperimentally,whichopensapathtoachievethree-dimensional(3D)nonlinearcrystalwithaperiodinsub-micron-scale.Asimulationofdomaininversionismodeledbyconsideringthetemporaldistributionoffemtosecondpulses.Thecalculationresultsclarifythatthedomaininversionscanhappenwithinoraftertheinteractionwiththelaserpulse,andtheresponsetimeofdomaininversionisinthepicosecondleveldependingontheintensityandthematerials.Thedomainreversalwindowsoflithiumniobatebyfemtosecondlaserareobservedwhichagreeswiththeoreticalpredictionsqualitatively.

简介：Theinfluenceofairturbulenceonthetransversewanderingofasinglefemtosecondlaserfilamentisstudiedbynumericalsimulation.Theresultsshowthattheaveragetransversedisplacementofthesinglefilament(δr}isproportionaltothesquarerootofturbulentstructureconstantandtherelationsbetweenandthepropagationdistancecanbefitbyapowerfunction.Inaddition,byusinganaxiconasafocusingoptics,thewanderingofasinglefilamentissuggestedtobestrongerthanthefree-propagationcase.

简介：Aswitchablemultiwavelengthlaserwithacontinuouslytunablespacingisproposedandillustratedbasedoncascadedinteractionsofthesecondharmonicanddifference-frequencygenerationsinanaperiodicallypoledMgO-dopedlithiumniobate(MgO:APPLN)waveguide.Thewavelengthsandwavelengthspacingsofthefouroutputsarecontinuouslyvariedandcontrolledbychangingthetwoinputpumpwavelengthsandspacingswithina3-nmflattopbandwidthofMgO:APPLN.Inaddition,theswitchablestatesofthefouroutputscanbeselectedbyinputtingproperpowersofthetwopumps.ThenumberofoutputwavelengthscanalsobeincreasedbychoosingtheproperAPPLNstructure,thetotallengthofMgO:APPLN,andhigherpowersofinputpumplights.