Optical fiber communication system

Abstract

PURPOSE: To provide a long-distance optical fiber communication system which propagates a linear polarized signal and can evade nonuniformity of the gain of polarity dependency, generated when the signal is amplified by an erbium- doped optical fiber amplifier, in such a case. CONSTITUTION: This optical fiber communication system has a reflector; and a light signal is passed through an optical fiber part doped with a rare earth element, and reflected and returned in its orthogonal polarity state to suppress the nonuniformity of the polarity gain. The Faraday rotation of the light signal by a Faraday mirror is an effective means which cancels the influence of polarity hole burning and the gain of the polarity dependency. COPYRIGHT: (C)1995,JPO