In view of the fiber-based all-optical regeneration based on Self-Phase Modulation(SPM) and Four-Wave Mixing(FWM) effects
this paper analyzes the limitation of regeneration towards RZ-DPSK modulation signals using SPM effect.This method can be used only when phase modulation is transformed to amplitude modulation.At the same time
it investigates the relationship to be met among pumped light
signal optical wavelength and zero-dispersion wavelength on the premise of high transformation efficiency by utilizing the FWM effect so as to insure the proper transfer function of regeneration.