NONLINEAR DISTORTION COMPENSATION METHOD FOR OPTICAL MODULATOR, LOW DISTORTION OPTICAL COMMUNICATION SYSTEM AND LOW DISTORTION OPTICAL MODULATOR

摘要

PROBLEM TO BE SOLVED: To provide a means and a method by which inter-modulation distortion caused by the nonlinear characteristic of an optical modulator is reduced.;SOLUTION: In the characteristic of an electro-absorption type modulator (an EA modulator) that is one type of optical modulators, the phase of inter- modulation distortion is suddenly shifted for 180° with respect to a bias voltage. The characteristic of the EA modulator is used in the following scheme, i.e., two EA modulators are operated in parallel and distortion generated by the modulators is mutually canceled with each other to reduce the distortion. Having constituted the above, a distortion generating circuit and a distortion phase reversal circuit, which are essentially required in a conventional distortion compensation method such as a predistortion distortion compensation method, are eliminated and distortion compensation is realized with a simple configuration.;COPYRIGHT: (C)2003,JPO