Patent ID: 7769300

Claim:
A method of reducing distortion of optical signal transmission in an optical communication system, comprising: providing the optical communication system having at least one section of optical transmission medium which exhibits one of a preferred and a substantially constant birefringence; transmitting an optical signal in the optical communication system; measuring a transmission quality of the optical signal of the optical communication system; transmitting the optical signal indicative of the measured transmission quality to a regulating device; driving, by the regulating device, a polarization-controlling device to alter the polarization of the optical signal so that the transmission quality is optimized; using a small coupled-out portion of communication-transmitting luminous flux of the optical signal to determine transmission quality; and redundantly monitoring the optical communication system by observing parity information extracted from the optical communication system, wherein when within the at least one section of optical transmission medium, the optical signal propagates only in one of a channel having a high rate of propagation and in a channel having a slow rate of propagation to prevent any splitting or widening of the optical signal.