简介：WeinvestigatethepropagationcharacteristicsofthenarrowbandStokes/anti-Stokesphotonsincoldatomicvapor.Thefour-wavemixingprocessresultsfromparametricamplificationoftheanti-Stokesphotons.Wefindthattheprocessofparametricamplificationisverysimilartothelightpulsepropagatingthroughananomalousdispersiongainmedium.Finally,weobtainthegeneralsolutionsoftheGlauberbiphotoncorrelationfunctions,whichareingoodagreementwiththeexperimentresults.

简介：Theeffectsofhighdrawingspeedsonparametersofholeyfibersarepresented.Aholeyfiberpreformstructurewasmadebyusingtube-in-tubemethodandwasdrawnathighspeedswithanaimofmassproductiontomeetthedemandofnextgenerationcommunicationsystems.Transmissionparameterssuchasnumericalapertureandnormalizedfrequencyofthefabricatedholeyfibershavebeenmeasuredandcomparedwiththeoreticalvaluesbasedoneffectiveindexmethod.Althoughthefabricatedholeyfiberswerenotofhighquality,theanalysesoftheparametershaveshownpromisingoutlookforfabricationofsuchfibers.

简介：Refractiveindicesforcrystalsammoniumdihydrogenphosphate(ADP),30%deuteratedADP(DADP),50%DADP,and70%DADParemeasuredfrom253to1529nmwith5×10-6accuracy.Numericalfitstomodifieddouble-poleSellmeierequationaremade.Second-harmonicgeneration,third-harmonicgenerationphasematching(PM)angles,andnoncriticalPM(NCPM)wavelengthsarecalculatedusingtheSellmeierparameters.ThedeuteratedcrystalsshowsmallerPManglesthanpurecrystal.Fourth-harmonicgenerationprocesscanberealizedbyDADPinsmallerdeuteriumcontentthandeuteratedpotassiumdihydrogenphosphate(DKDP).ThemeasuredNCPMwavelengthsareconsistentwiththecalculatedvalue.PMcharacteristicsarecomparedbetweenDADPandDKDP.

简介：Weproposeaspeckle-reductionmethodbasedonwavelengthcharacteristicsofspeckleeffectinsyntheticapertureimagingladar(SAIL).Thereturnsignal,whichisthebackscatteringfieldwithspeckleeffectfromtheroughsurfaceoftarget,canbeintegratedoverNchirpperiodsandheterodynedetectedwithalocal-oscillatorsignal.Afterperformingimageprocessingrespectively,thefinalimagecanberegardedastheincoherentsuperpositionoftheNsub-images.Numericalsimulationsindicatetheeffectivenessofthismethod.OurresearchmayfacilitatepracticalapplicationsofSAIL.

简介：Thenonlinearswitchingcharacteristicsoffusedfiberdirectionalcouplerswerestudiedexperimentally.Byusingfemtosecondlaserpulseswithpulsewidthof100fsandwavelengthofabout1550nmfromasystemofTi:sapphirelaserandopticalparametricamplifier(OPA),thenonlinearswitchingpropertiesofanullcoupleranda100%couplerweremeasured.Theexperimentalresultswerecoincidentwiththesimulationsbasedonnonlinearpropagationequationsinfiberbyusingsuper-modetheory.Nonlinearlossinfiberwasalsomeasuredtogettheinjectedpoweratthecoupler.Afterdeductingthenonlinearlossandinputefficiency,thenonlinearswitchingcriticalpeakpowersfora100%andanullfusedcouplerswerecalculatedtobe9410and9440W,respectively.ThenonlinearlossparameterPNinanexpressionofαNL=αP/PNwasobtainedtobePN=0.23W.

简介：Thecavitytuningcharacteristicsoforthogonallypolarizeddual-frequencyHe-Nelaserat1.15μmarepresented.Vectorial-extensionmodelbasedonsemi-classicallasertheoryrevealsthatcavitytuningcharacteristicsarerelatedtobeatfrequency,relativeexcitation,andtypeofNeisotope.Distortionsofcavitytuningcurvesbecomemoderatewiththeincreaseofbeatfrequencybecauseoftheweakeningofthecrosssaturationeffect.Distortionsareenhancedwiththeincreaseofrelativeexcitationbecauseofthecombinedactionoftheself-saturationandcross-saturationeffects.Byadoptingdual-isotopeNeinsteadofmonoiso-toplicNe,distortionsarereducedbecauseofthemisalignmentbetweenpeaksoftheself-saturationandnetgaincoefficients.Thetheoreticalcalculationsareingoodagreementwiththecorrespondingexperimentalresults.

简介：ThestimulatedBrillouinscattering(SBS)thresholdaffectedbyrepetitionrateandpulsedurationinasinglefrequencynanosecondpulsedfiberamplifierisstudied.TheexperimentalresultsdemonstratethattheSBSthresholdcanbeimprovedeitherbyreducingtherepetitionrateorbynarrowingthepulseduration;however,theaveragepowermaybelimitedinsomecases.Otherwise,twoevaluationmethodsfortheSBSthresholdinthefiberamplifierarecomparedanddiscussed,aimingtoobtainamoreaccuratedescriptionfortheSBSthresholdinoursingle-frequencyamplifiersystem.