简介:Biasofring-laser-gyroscope(RLG)changeswithtemperatureinanonlinearway.ThisisanimportantrestrainingfactorforimprovingtheaccuracyofRLG.Consideringthelimitationsofleast-squaresregressionandneuralnetwork,weproposeanewmethodoftemperaturecompensationofRLGbiasbuildingfunctionregressionmodelusingleast-squaressupportvectormachine(LS-SVM).StaticanddynamictemperatureexperimentsofRLGbiasarecarriedouttovalidatetheeffectivenessoftheproposedmethod.Moreover,thetraditionalleast-squaresregressionmethodiscomparedwiththeLS-SVM-basedmethod.TheresultsshowthemaximumerrorofRLGbiasdropsbyalmosttwoordersofmagnitudeafterstatictemperaturecompensation,whilebiasstabilityofRLGimprovesbyoneorderofmagnitudeafterdynamictemperaturecompensation.Thus,theproposedmethodreducestheinfluenceoftemperaturevariationonthebiasoftheRLGeffectivelyandimprovestheaccuracyofthegyroscopeconsiderably.
简介:Wepresentanovelcoherenttransceiverforopticaldifferentialphase-shiftkeying/differentialquadraturephase-shiftkeying(DPSK/DQPSK)signalsbasedonheterodynedetectionandelectricaldelayinterferometer.Asimulationframeworkisprovidedtopredictatheoreticalsensitivitylevelforthereportedscheme.Highsensitivityof-45.18dBmisachievedfor2.5-Gb/sreturn-to-zero(RZ)-DPSKsignal,andhighsensitivitiesof-36.83dBm(Itributary)and-35.90dBm(Qtributary)areobservedfor2.5-GBaud/sRZ-DQPSKsignalinback-to-backconfiguration.Transmissionforbothsignalsover100kmisalsoinvestigated.Experimentalresultsarediscussedandanalyzed.
简介:Wehavestudiedafunction-lockstrategyforall-opticallogicgate(AOLG)utilizingthecross-polarizationmodulation(CPM)effectinasemiconductoropticalamplifier(SOA).Bymonitoringthepoweroflogiclight,thestrategyrealizedcontrollablemethodstocaptureORandNORfunctionsandswitchbetweenthem.Thestrategyhasbeensuccessfullyappliedinexperimentwith10-Gb/snot-return-to-zero(NRZ)signals,whichhasahighsuccess-rateabove95%andensuresthehighextinctionratioofresultlightabove11.4dB.Everystepinthestrategyhasdefinitenumericevaluation,whichprovidesthepotentialofautomaticimplementation.
简介:Acombinationoflight-emittingdiode(LED)identificationandatime-divisionmultiplexingschemeisproposedinthisLetterforindoorlocation-basedservice.Withthescheme,thearrangementofwhiteLEDlampsandthestructureofadataframearedesignedtorealizehigh-accuracyindoorpositioningandlocation-basedpayloaddatatransmissionsimultaneously.Theresultsoftheexperimentdemonstratethattheindoorpositioningaccuracyis10cmand2Mb/sdatatransmissionwithhighsignalqualityisrealized.
简介:TransientthermalimpedanceofGaN-basedhigh-powerwhitelightemittingdiodes(LEDs)iscreatedusingathermaltransienttester.Anelectro-thermalsimulationshowsthatLEDjunctiontemperature(JT)risestoaverylowdegreeunderlowdutycyclepulsedcurrent.AtthesameJT,emissionpeaksareequivalentatpulsedandcontinuouscurrents.Moreover,thediferenceinpeakwavelengthwhenaLEDisdrivenbypulsedandcontinuouscurrentsinitiallydecreasesthenincreaseswithincreasingpulsewidth.Thus,selectinganappropriatepulsewidthdecreaseserrorsinJTmeasurement.
简介:Amethodtothree-dimensionalpositionmovingparticleswithonelensandtwocamerasisproposed.Twoparticleimageswithdifferentdegreesofdefocusingareadoptedtosolvetheambiguousproblemofparticlepositions.Asingle-lensdual-camerasystemisdevelopedtosimultaneouslycapturethesetwoimagesforthemovingparticles.Themeasurementprinciplesandtheoreticalanalysisareintroducedfirst,andthensimulatedinvestigationsandexperimentalresearcharediscussed.Themeasurementerrorsinthesimulationsandexperimentsarelessthan1%and4%,respectively,in20timesthedepthoffieldofthesystem,whichvalidatesthefeasibilityofthismethod.
简介:Anopticalbandpassfilter(OBF)isanimportantelementwhosepropertiesconsiderablyinfluencetheoutputperformanceofasinglesidebandmulticarriersourcebasedonare-circulatingfrequencyshifter.TheinfluenceoftheOBFintheloopontheoutputspectrumistheoreticallyanalyzed.Numericalsimulationsandexperimentsarealsocarriedout.Resultsshowthatthesteepnessanddeepnessofanonflat-topfilterinfluencethestabilityofthespectrumofanoutputmulticarrier.Toobtainmulticarrieroutputwithtonetonoiseratio(TNR)>26dBanderrorvectormagnitude(EVM)<0.25,thesteepnessratioofthefiltershouldbegreaterthan0.75anddeepnessshouldbelargerthan0.99.
简介:40-GHzclockmodulatedsignalasapumptoimprovetheefficiencyoffour-wavemixing(FWM)-basedwavelengthconversionina26.5-kmdispersionshiftedfiber(DSF)isinvestigated.TheexperimentalresultsdemonstratethattheconjugatedFWMcomponenthashigherintensitywiththeclockpumpingthanthatwiththecontinuous-wave(CW)lightpumping.TheimprovementofFWM-basedwavelengthconversionefficiencyisnegligiblewhenthepumppowerislessthanBrillouinthreshold.ButwhenthepumppowerisgreaterthanBrillouinthreshold,theimprovementbecomessignificantandincreaseswiththeincrementofpumppower.Theimprovementcanincreaseupto9dBifpumppowerreaches17dBm.
简介:Non-uniformstep-sizedistributionisimplementedforsplit-stepbasednonlinearcompensationinsingle-channel112-Gb/s16quadratureamplitudemodulation(QAM)transmission.Numericalsimulationsofthesystemincludinga20×80kmuncompensatedlinkareperformedusinglogarithmicstepsizedistributiontocompensatesignaldistortions.50%ofreductioninnumberofstepswithrespecttousingconstantstepsizesisobserved.Theperformanceisfurtherimprovedbyoptimizingnonlinearcalculatingposition(NLCP)incaseofusingconstantstepsizeswhileNLCPoptimizationbecomesunnecessarywhenusinglogarithmicstepsizes,whichreducesthecomputationaleffortduetouniformlydistributednonlinearphaseforallsuccessivesteps.
简介:Wereportontheamplificationofhigh-average-powerandhigh-efficiencypicosecondpulsesinaself-madeverylarge-mode-areaYb-dopedphotoniccrystalfiber(PCF).ThePCFwithacorediameterof105μmandacorenumericalapertureof0.05ispreparedbythesol-gelmethodcombinedwiththepowdersinteringtechnique.Thefiberamplificationsystemproducesthehighestaveragepowerof255Wata10MHzrepetitionratewitha21pspulsedurationcorrespondingtoapeakpowerof1.2MW.Thisresultexemplifiesthehigh-average-powerandhigh-peak-powerpotentialofthisspecificallydesignedfiber.