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