DISPERSION COMPENSATION WITH PHASE-SENSITIVE OPTICAL AMPLIFIERS

Recently, we proposed a novel approach to combating the pulse-broadeni ng effect of group-velocity dispersion (GVD) in a fiber-optic communic ation link (IEEE Photon. Technol. Leu., vol. 5, pp. 669-672, 1993). In our scheme, linear loss in the fiber is balanced by a chain of period ically spaced, phase-sensitive optical amplifiers. In this paper, we p resent a detailed analysis of pulse propagation in such a fiber line s howing that, due to attenuation in the quadrature orthogonal to the am plified quadrature, it is possible for a pulse to propagate without si gnificant broadening over lengths many times longer than the usual dis persion length of the fiber. An averaged equation for pulse evolution over distances longer than the amplifier spacing is derived. The effec t of optical-phase fluctuations between the propagating pulse and the amplifiers is also considered. Since our proposed scheme does not rely on the formation of solitons in the fiber, it can be implemented in b oth the positive and negative GVD regions, and it does not require a m inimum peak power for the pulses.