简介：Consideringasingle-modelasersystemwithcross-correlatedadditivecolorednoiseandmultiplicativecolorednoise,westudytheeffectsofcorrelationamongnoisesonthenormalizedintensitycorrelationfunctionC(s).C(s)isderivedbymeansoftheprojectionoperatormethod.Theeffectsoftheself-correlationtimeτ_1oftheadditivecolorednoise,τ_2ofthemultiplicativecolorednoise,andtheeffectofthecross-correlationtimeτ_0betweenthetwonoisesonC(s)arediscussedbynumericalcalculation.Forthecaseofpositivecorrelation(λ>0),itisfoundthatwhena_0>0thenormalizedintensitycorrelationfunctionC(s)increaseswiththeincreaseofToorτ_2,andwithvalueofτ_0orτ_2becominglarger,C(s)comestosaturation.Withincreasingtheself-correlationtimeτ_1oftheadditivenoise,aminimumandamaximumwillappearoncurveofC(s)asa_0>0.Ifa_0<0,C(s)decreaseswiththeincreaseofτ_0,τ_1,andτ_2.

简介：Aquasi-cycliclow-densityparitycheck(QC-LDPC)codeisconstructedbyanimp

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：Opticalperformancemonitoringusingasynchronousopticalorelectricalsamplinghasgainedconsiderableattention.Relativeclockwanderbetweendatasignalandsamplingsourceisatypicaloccurrenceinsuchsystems.Amethodforthequantitativemonitoringoftherelativeclockwanderinasynchronousopticalundersamplingsystemispresented.Withaseriesofsimulations,theclockwandersrecoveredusingthismethodareingoodagreementwiththepresetclockwandersofdifferentamountsandfrequenciesforbothRZandNRZsignals.Hence,thereliabilityandrobustnessofthemethodareproven.

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

简介：Anovelmethodfordistortion-freeopticalpulsetransmissionistheoreticallyproposedandsimulated,inwhichtwotimelensesformedbydispersionfibersandquadraticphasemodulationsareutilized.OneisusedasanopticalinverseFouriertransformation(OIFT)devicetotransformtheinitialtime-domaindatatofrequency-domainoneatthetransmitterandtheotherasanopticalFouriertransformation(OFT)devicetorecoverthedataatthereceiver.Byusingtheunchangedspectralenvelopeinlinearopticalfibercommunication,theinitialdatacanberecovered.Throughsimulations,a10×100Gb/sintensitymodulateddirect-detection(IM-DD)densewavelengthdivisionmultiplexing(DWDM)systemover2000kmtransmissionwithoutthecompensationforpolarizationmodedispersion(PMD)anddispersionslopeisachieved,whichcanbeusedtoupgradethecurrent10-Gb/sIM-DDsystemtoa100-Gb/sonedirectly.

简介：Thebehaviorofpopulationtransferinanexcited-doubletfour-levelsystemdrivenbylinearpolarizedfew-cycleultrashortlaserpulsesisinvestigatednumerically.Itisshownthatalmostcompletepopulationtransfercanbeachievedevenwhentheadiabaticcriterionisnotfulfilled.Moreover,therobustnessofthisschemeintermsoftheRabifrequenciesandchirpratesofthepulsesisexplored.

简介：四通八达的高速路和各式各样的封闭道路加快了城市地区间的互通有无，与以往相比，长途驾驶的高车速、大流量特点有效缩短了交通时间，大大提高了出行的便捷性。但是高速路的独立式设计、封闭或半封闭的行驶状态都对行驶路线有特殊要求，一旦拐入错误的出入口或驶上错误的路线，反而事倍功半，降低出行效率。由此可见，对行车路线的不熟悉是困扰很多驾驶员已久的难题，

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简介：Amethodtothree-dimensionalpositionmovingparticleswithonelensandtwocamerasisproposed.Twoparticleimageswithdifferentdegreesofdefocusingareadoptedtosolvetheambiguousproblemofparticlepositions.Asingle-lensdual-camerasystemisdevelopedtosimultaneouslycapturethesetwoimagesforthemovingparticles.Themeasurementprinciplesandtheoreticalanalysisareintroducedfirst,andthensimulatedinvestigationsandexperimentalresearcharediscussed.Themeasurementerrorsinthesimulationsandexperimentsarelessthan1%and4%,respectively,in20timesthedepthoffieldofthesystem,whichvalidatesthefeasibilityofthismethod.

简介：Alowcost8×10-Gb/stransmissionsystemover1500kmonconventionalfiberusingchirpedfiberBragggrating(CFBG)asdispersioncompensatorisdemonstrated.Thebiterrorrate(BER)below10-10at1500kmisobtained.Thechannelspacingis0.8nmandtheopticalamplifierspacingis100km.Only16erbium-dopedfiberamplifiers(EDFAs)areused.