WAVELENGTH MULTIPLE OPTICAL COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a wavelength multiple optical communication system with which quality is improved by suppressing the mixture of four optical waves caused by the non-linear optical characteristics of an optical fiber. SOLUTION: A wavelength multiple signal light source 3 generates wavelength multiple signal light having at least two different wavelengths in the wavelength band of wavelengths from about 1570 to 1600 nm. An optical amplifier 1 amplifies the wavelength multiple signal light of this wavelength band, and distributed shift fibers 2 for transmitting the wavelength multiple signal light are made into optical fibers having zero distributed wavelengths in the band of the wavelength of 1.55 μm out of the wavelength of the wavelength multiple signal light. The optical amplifier 1 is constituted by providing an erbium added optical fiber, excited light source and the light source of inverted distribution control light for regulating inverted distribution inside the erbium added optical fiber, the product of the erbium density and optical fiber length of the erbium added optical fiber is made more than 60000 ppm.m, and the excited light intensity of the excited light source is made more than 300 mW.