1. Introduction
Recovery of carrier from data-modulated optical signals is an important task in coherent homodyne detection and all-optical signal processing such as phase-sensitive amplification. Recently several approaches for the carrier extraction from carrier-less phase shift keying (PSK) signals have been reported. In [1], all-optical carrier extraction by a fiber-based phase sensitive oscillator pumped by amplified binary PSK (BPSK) signals was demonstrated. In [2], feed-forward carrier extraction using optical-electrical-optical modulation stripping together with injection locking of a laser diode (LD) was proposed. In [3], low-speed electrical signal processing combined with all-optical modulation stripping by the parametric process in a nonlinear fiber was used for carrier extraction from high baud rate PSK signals.