Compensation of intrachannel nonlinearities in 40-Gb/s pseudolinear systems using optical-phase conjugation

In this paper intrachannel nonlinearities in a return-to-zero differential-phase-shift-keyed (RZ-DPSK) 40-Gb/s 32/spl times/100-km system are compensated in the absence of signal power symmetry using a single LiNbO/sub 3/ conjugator and results in two decades of improvement in bit-error rate (BER). The reduction of transmission impairments enables the reach of the system to be extended from 5200 to 6400 km with a measured BER =5/spl times/10/sup -4/. This paper also presents a first-order perturbation analysis that describes the effects of optical-phase conjugation and dispersion mapping on the optical field of pulses.