简介:Thekernelbasedtrackinghastwodisadvantages:thetrackingwindowsizecannotbeadjustedefficiently,andthekernelbasedcolordistributionmaynothaveenoughabilitytodiscriminateobjectfromclutterbackground.Forboostingupthefeature'sdiscriminatingability,bothscaleinvariantfeaturesandkernelbasedcolordistributionfeaturesareusedasdescriptorsoftrackedobject.Theproposedalgorithmcankeeptrackingobjectofvaryingscalesevenwhenthesurroundingbackgroundissimilartotheobject'sappearance.
简介:Directcalculationsofabsorptionspectraformulti-quantumwellstructuresbyextractingfielddistributionsatwellpositionsareperformed.ResultsdemonstratethepreviouslyreportedBraggsuppression,andagreeexactlywiththeindirectcalculationbylineardispersiontheory.ThisrevealsthatBraggsuppressioneffectinfactoriginatesfromtheremarkablydecreasedintensitiesatwellpositionsbyBragginterferencecondition,ratherthanfromtheformationofsupperradiantmodes.
简介:Scalefactorofaconstantratebiasedringlasergyro(RLG)isstudiedboththeoreticallyandexperimentally.Byanalyzingexperimentaldata,wefindthattherearethreemaintermscontributingtothescalefactordeviation.Oneofthemisindependentoftime,thesecondvarieslinearlywithtimeandthethirdvariesexponentiallywithtime.Theoreticalanalysesshowthatthefirsttermiscausedbyexperimentalsetup,thesecondandthethirdarecausedbyun-uniformthermalexpensionandcavitylossvariationoftheRLG.
简介:Weinvestigatetheopticalbistabilityandmultistabilitybehaviorsinaclosedthree-levelΛ-typeatomicsystem.Byaddingasidebandoneitherhandofthetransitionswhichareoriginallycoupledbyacoherentcontrolfieldandacoherentprobefieldtodisturbthetwo-photonresonance,bistabilityoccursduetotwo-channelinterference.IncreasingthesidebandRabifrequencyleadstotheswitchingfrombistabilitytotristability.Whenthesidebandsimultaneouslycoupleswithbothhands,wecaneasilyobtainquadrastability.
简介:Anewlocallyadaptiveimagedenoisingmethod,whichexploitstheintrarscaleandinter-scaledependencyinthedual-treecomplexwaveletdomain,ispresented.Firstly,arecentlyemergedbivariateshrinkageruleisextendedtoacomplexcoefficientanditsneighborhood,thecorrespondingnonlinearthresholdfunctionsarederivedfromthemodelsusingBayesianestimationtheory.Secondly,anadaptiveweight,whichisabletocapturetheinter-scaledependencyofthecomplexwaveletcoefficients,iscombinedtotheobtainedbishrinkthreshold.Theexperimentalresultsdemonstrateanimproveddenoisingperformanceoverrelatedearliertechniquesbothinpeaksignal-to-noiseratio(PSNR)andvisualeffect.
简介:Aspectral-based8-inkcharacterizationmodelisdevelopedtoaccuratelypredicttherecipeforamulti-inkprinter.The8-inkcolorseparationmethodisaunionoffive3-inkandsix4-inkcombinationsbasedonthecellularYule-NielsenspectralNeugebauermodelwitharecipeselectionstrategy.Theperformancelevelsoftheforwardandbackwardmodelsareevaluatedforindividualinkcombinationsusingprintedtestingsamples.Furthermore,thespectral-basedmethodperformsbettercomparedwiththeXYZ-basedapproach.Onthebasisofthebackwardmodelperformance,anovelfastrecipeselectionstrategyisproposedandestimated.
简介:Asimplifiedringcavityforachievingaunidirectionalroomtemperaturemulti-wavelengtherbium-dopedfiberringlaserwithoutopticalisolatorisdemonstrated.ThefiberringcavityisbuiltinsuchawaythattheopticalfieldspropagatingintwodirectionssufferdifferentlossescausedbyonesampledfiberBragggrating.Furthermore,simultaneousmulti-wavelengthlasingwith0.8-nmintervalsisdemonstratedwithsinusoidalphasemodulationjustbeforethesampledfiberBragggratingtopreventsingle-wavelengthlasingandunstablewavelengthoscillation.
简介:Graycrosscorrelationmatchingtechniqueisadoptedtoextractcandidatematcheswithgraycrosscorrela-tioncoefficientslessthansomecertainrangeofmaximalcorrelationcoefficientcalledmulti-peakcandidatematches.Multi-peakcandidatesareextractedcorrespondingtothreeclosestfeaturepointsatfirst.Thecorrespondingmulti-peakcandidatematchesareusedtoconstructthemodelpolygon.Correspondenceisdeterminedbasedonthelocalgeometricrelationsbetweenthethreefeaturepointsandthemulti-peakcandidates.Thedisparitytestandtheglobalconsistencycheckoutareappliedtoeliminatetheremainingambiguousmatchesthatarenotremovedbythelocalgeometricrelationaltest.Experimentalresultsshowthattheproposedalgorithmisfeasibleandaccurate.
简介:Weproposesomenewschemestoconstitutetwo-dimensional(2D)arrayofmulti-wellopticaldipoletrapsforcoldatoms(ormolecules)byusinganopticalsystemconsistingofabinaryπ-phasegratinganda2Darrayofrectanglemicrolens.Wecalculatetheintensitydistributionofeachopticalwellin2Darrayofmulti-welltrapsanditsgeometricparametersandsoon.Theproposed2Darrayofmulti-welltrapscanbeusedtoformnovel2Dopticallatticeswithcoldatoms(ormolecules),andformvariousnovelopticalcrystalswithcoldatoms(ormolecules),ortoperformquantumcomputingandquantuminformationprocessingonanatomchip,eventorealizeanarrayofall-opticalmulti-wellatomic(ormolecular)Bose-Einsteincondensates(BECs)onanall-opticalintegratedatom(ormolecule)chip.
简介:Asthewavelengthdivisionmultiplexing(WDM)technologymaturesandthedemandsforbandwidthincrease,survivabilitybecomesmoreandmoreimportantingeneralizedmulti-protocollabelswitching(GMPLS)controlledintelligentopticalnetworks(IONs).Therearegreatintereststostudytheperformanceofrestorabilityunderonecertainconnectionmanagementstrategy.Andstudiesintheproblemofprovidingrecoveryfromlinkfailuresundertwodifferentresourcereservationschemes,forwardreservationprotocols(FRPs)andbackwardreservationprotocols(BRPs),arepresented.Theyareexaminedfromthepointofviewofconnectionblockingprobability,restorabilityandaveragerecoverytime.Thetwodifferentconnectionmanagementschemesandthesurveyofdifferentrecoveryschemesarefirstpresented.Theperformanceoftheserecoverystrategiesisanalyzedandcomparedboththroughtheoreticalanalysisandsimulationresults.ThemainstressedideaisthatusingBRPsgivesthebestperformanceintermsofrestorabilityandblockingprobabilityinrestorableGMPLSnetworks.
简介:Themulti-photonionizationspectrumofNOinthewavelengthregionof575-680nmisobtainedwithanopticalparametergeneratorandamplifier(OPG/OPA)pumpedbyapicosecondNd:YAGlaserasradiationsource.ThebandedstructureofthespectrumindicatesthatNOmoleculeisionizedinresonantmannerandthepeaksofthespectrumareassignedtothetransitionofNOmoleculefromthegroundelectronicstatetoA2∑(v'=0,1,2,3),E2∑(v'=0,1,2),F2Δ(v'=0,1,2,3)andH2∑(v'=0,1,2)intermediateresonantones.ThemoleculeconstantsaboutNO(A2∑,E2∑,F2Δ,H2∑)statesarecalculatedfromthecenterwavelengthofthespectrum.ItisalsofoundthatowingtothespecialelectronconfigurationofNO,thismoleculedoesnotfollowthenormaltransitionselectionruleofthediatomicmoleculeduringthemulti-photonprocess.
简介:Byinvestigatingthecross-spectraldensityofpartiallycoherentmulti-rotatingellipticalGaussianbeams(REGBs)thatpropagatethroughafocusingopticalsystem,weobtaintheradiationforceonaRayleighparticle.Theradiationforcedistributionisstudiedunderdifferentbeamindexes,coherencewidths,andellipticalratiosofthepartiallycoherentmultiREGBs.Thetransverseandthelongitudinaltrappingrangescanincreaseatthefocalplanebyincreasingthebeamindexordecreasingthecoherencewidth.Therangeofthetrappedparticleradiiincreasesastheellipticalratioincreases.Furthermore,weanalyzethetrappingstability.
简介:Thenonlineareffectsthatlimittheperformanceofthemulti-frequencyprobe(MFP)basedcoherentopticaltimedomainreflectometry(C-OTDR)areinvestigated.Basedontheoreticalanalysisandexperimentalresults,comparedwithconventionalC-OTDR,whentheprobepulsehaspowergradientwithinthepulsewidth,self-phasemodulation(SPM)andcross-phasemodulation(XPM)arestrengthenedinthenewC-OTDRscheme.Thegenerationoffour-wavemixing(FWM)isdependentonSPMandXPM,andwithmodulationfrequencyofphasemodulatorhigherthan40MHz,thestimulatedBrillouinscattering(SBS)thresholdcanbeenhancedbymorethan5dB,whichbenefitsthemaximumdynamicrangeoftheMFPC-OTDR.
简介:Weproposeahighsensitivitysensorbasedonamodenumber-encodedmulti-longitudinalmodefiberlaser.ThefiberlaserincorporatesauniformfiberBragggrating(FBG)andafiberFabry-Perotinterferometer(FFPI)assensitivecomponentsinthecavity.Thesensorcountsthenumberoflongitudinalmodes(NLM)offiberlaser,whichiscausedbythemismatchbetweenthereflectionbandofFBGandthetransmissionbandofFFPIresultingfromtheapplicationofexternalperturbationtotheFBG.AnelectricalspectrumanalyzerisadoptedtoanalyzetheNLM.Thestrainsensorisexperimentallydemonstratedtohavesensitivityofashighas0.02με/mode.
简介:Weproposeanovelschemeforopticalfrequency-lockedmulti-carriergenerationbasedonadirectlymodulatedlaser(DML)andaphasemodulator(PM)incascadethroughsynchronoussinusoidalradiofrequency(RF)signal.TheoptimaloperatingzoneforthecascadedDMLandPMschemeisdeterminedviatheoreticalanalysisandnumericalsimulation.Wedemonstrate16opticalsubcarrierscanbesuccessfullygeneratedbasedonthecascadedDMLandPMschemeintheoptimalzone.Thegenerated16opticalsubcarrieshavefrequencyspacingof12.5GHzandpowerdi?erenceoflessthan3dB.Theseresultsagreewellwiththoseofthenumericalsimulation.Wealsodemonstrateintensitymodulationanddirectdetection(IM-DD)basedononeofthe16generatedopticalsubcarriers.After20-kmsingle-modefiber-28(SMF-28)transmission,thebit-errorratio(BER)of1×10-9canbeattainedforboth3.125-and12.5-Gb/sbitrates.
简介:Anall-fiberopticallaserpulsemulti-passstretcherusingachirpedfiberBragggrating(CFBG)isdemonstrated.Pulsesfroma1053-nmmode-lockedfiberseedoscillatorarestretchedbymultiplepassingthroughachirpedfibergratingsetinafiberregenerativeamplifierstructure.Westretchthepulsefrom16psto1.855nsafterittransmitssevenloopsinthestretcher.Themainfactorsthataffectthestretchingresultsarediscussed.