简介：Amultichannelpolarization-entangledphoton-pairsourceinanMgO-dopedperiodicallypoledlithiumniobate(MgO:PPLN)waveguideisproposed.BasedontypeIquasi-phase-matchedspontaneousparametricdownconversioninasingleMgO:PPLNwaveguideplacedinsideaSagnacinterferometerandpumpedbymonochromaticlight,asourcecapableofsupportingtenstohundredsofchannelsofpolarization-entangledphotonpairsinfibercommunicationbandssimultaneouslycanbeachieved.Aninherentchannelswitchofthissourceisinvestigated,whichwillbesignificantforfutureentanglementdistributionnetworks.

简介：

简介：Quantumkeydistribution(QKD)isamajorresearchtopicbecauseitprovidesunconditionalsecurity.Unfortunately,manyimperfectionsremaininQKD’sexperimentalrealization.TheFaraday–Michelson(FM)QKDsystemisproposedtoeliminatetheseimperfectionsusingpolarization.However,thelongarm’sphasemodulator(PM)hasanunexpectedinsertionloss,meaningthatthestatesentisnolongerperfect.Inthisletter,weproposeanalternativeFM-QKDsystemstructure,andanalyzethesecurityandkeygenerationrateincomparisonwiththeoriginalsystemviadifferentanalysismethods.WefindanobviouskeyrateimprovementwhenthePMinsertionlossisnotextremelysmall.

简介：

简介：Anoptimalpowerdistributionanalysisforanall-opticalsamplingorthagonalfrequencydivisionmultiplexing(OFDM)schemewithmultiplemodulationformatsincludingdiferentialphaseshiftkeyed(DPSK),diferentialquadraturephaseshiftkeyed(DQPSK),andnon-return-to-zero(NRZ)isproposed.Thenoisetolerancesofdifferentmodulationformatsareanalyzed,andtheoptimalinputpowerratiobetweenphaseandintensitymodulationformatsforthebestoverallreceivingperformanceisinvestigatedunderunchangedtotalinputpower.Moreover,thisschemecanseamlesslycoexistwiththetraditionalWDMchannel.

简介：Measurementoflightdistributioninbiologicaltissuecontributestoselectingstrategyandoptimizingdoseforbiomedicalapplication.Inthisletter,aphotoacousticmethodcombinedwithMonteCarlosimulationwasusedtoestimatethethree-dimensionallightdistributioninbiologicaltissue.Thelightdistributionwasproducedbyacylindricaldiffuserwhichinterposedintotissues.Thelightprofilesobtainedbythemethodwerecomparedtothosedetectedbyphotodiodes.Theexperimentalresultsdemonstratethefeasibilityofthismethod.Theapproachcanplayasignificantroleforphoto-dosimetryinbiomedicalphototherapy.

简介：