Polarization modulation in wavelength division multiplexed transmission systems

摘要

Four-wave mixing between multiplexed channels in a wavelength division multiplexed optical transmission system, and the effects of polarization-dependent hole burning, are simultaneously reduced, in accordance with the invention, by a method and apparatus which provides for modulating a state-of-polarization of an optical signal so that an average-value of the state-of-polarization over each modulation cycle is substantially equal to zero; and, orienting a state-of-polarization of at least one channel of the optical signal to be substantially orthogonal to a state-of-polarization of at least one other channel of the optical signal while maintaining the substantially zero average value of the state-of-polarization of the optical signal over each modulation cycle.