简介：Consideringanopticalbistablesystemwithcross-correlatedadditivewhitenoiseandmultiplicativecolorednoise,westudytheeffectsofcorrelationbetweenthenoisesonthecorrelationfunctionC(s)usingtheunifiedcolorednoiseapproximationandtheStratonovichdecouplingansatzformalism.Theeffectsoftheself-correlationtimeTofthemultiplicativecolorednoiseandthecorrelationintensityλbetweenthetwonoisesarestudiedwithnumericalcalculation.ItisfoundthatC(s)increaseswiththeincreaseoftheself-correlationtimeT,butdecreaseswiththeincreaseofthecorrelationintensityλ.AtlargevalueofT,thereisalmostnochangeforC(s)whenTchanges.

简介：Targetdynamicsareassumedtobeknowninmeasuringdigitalspeckledisplacement.Useismadeofasimplemeasurementequation,wheremeasurementnoiserepresentstheeffectofdisturbancesintroducedinmeasurementprocess.Fromtheseassumptions,Kalmanfiltercanbedesignedtoreducevarianceofmeasurementnoise.Anopticalandanalysissystemwassetup,bywhichobjectmotionwithconstantdisplacementandconstantvelocityisexperimentedwithtoverifyvalidityofKalmanfilteringtechniquesforreductionofmeasurementnoisevariance.

简介：Inholographicencryption,doublerandom-phaseencodingintheFresneldomain(DRPEiFD)isaprevalentencryptionmethodbecauseitislenslessandsecure.However,noisesbringadverseeffectsduringdecryption.Inthisletter,weintroducequick-response(QR)codingduringencryptiontoresistnoises.WetransformtheoriginalinformationintoaQRcodeandthenencryptthecodeasahologramthroughDRPEiFD.Toretrievetheinput,wedecryptthehologramintheoppositemannertotheencryptionandsubsequentlyobtainaQRcodewithnoises.Byscanningthiscodewithproperapplicationsinsmartphones,wecanobtainanoise-freeretrieval.Numericalexperimentsandimagesscannedbyasmartphoneareshowntovalidateourproposedmethod.

简介：Anintegratedmethodbasedonopticalanddigitalimageprocessingispresentedtosuppressspeckleindigitalholography.Aspatiallightmodulatorisadoptedtointroducerandomphasestotheilluminatingbeam.Multiplehologramsarereconstructedandsuperimposed,andtheintensityisaveragedtosmooththenoise.Theadaptivealgorithmbasedonthenonlocalmeansisdesignedtofurthersuppressthespeckle.Thepresentedmethodiscomparedwithothermethods.Theexperimentalresultsshowthatspecklereductionisimproved,andtheproposedmethodiseffectiveandfeasible.

简介：Anumericaldesignonthetriangularphotoniccrystalfiber(PCF)basedbackwardmulti-pumpRamanamplifierispresented.ItisdemonstratedthathighflatRamangaincanbereachedbasedonPCF.InfluencesofdifferentgeometricparametersandgermaniumdopingconcentrationsontheRamannetgain,amplifiedspontaneousemission(ASE)noiseanddoubleRayleighbackscattering(DRBS)ofthesignalhavebeenanalyzed.ForoptimizingcrystalfiberRamanamplifier(FRA),thereistradeoffbetweenthegeometricparameterandgermaniumdopingconcentrationoftriangularPCF.TheresultsshowthatPCFisanappropriatecandidateforhighgainRamanamplifiers.

简介：WeproposeaschemeformitigatingRayleighbackscatteringnoiseanddemodulatingdifferentialphaseshiftkeying(DPSK)signalsinwavelength-division-multiplexedpassiveopticalnetworks(WDM-PONs)withinjection-lockedFabry-Perotlaserdiodes(FP-LDs).SignaldemodulationandwavelengthconversionaresimultaneouslyrealizedonthebasisofthefrequencydeviationandredshiftoflongitudemodesintheFP-LDs.Experimentalresultsdemonstratethatthedemodulationandwavelengthconversionof2.5-Gb/sDPSKsignalsareachieved.Apowerpenaltyofabout1.6dBatabiterrorrateof109ismeasuredaftertransmissionover25-kmsinglemodefiber.