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.