OPTICAL COMMUNICATION SYSTEM USING HIGH ORDER RAMAN AMPLIFIER

摘要

PROBLEM TO BE SOLVED: To realize a low noise, a long fiber span and low nonlinearity by providing one or plural high order dispersion Raman effect amplifiers on a poststage of a light source. SOLUTION: Plural Raman amplifiers 10 are provided on the poststage of a signal light source along a transmission line 12 over the whole length of the transmission line 12. The amplifier 10 is preferred to be provided on an end part of a middle of a continuous fiber segment. The usual high order Raman amplifier 10 is constituted of one or above of Raman pump light source 20A and one or above of secondary Raman pump light source 20B. The light sources 20A, 20B are usually semiconductor lasers connected with a thing such as a connector transmission line segment 21. These are connected in the fiber transmission lines 12 by a wavelength division multiplexing device 22. This advantage exists in a point that the cross talk is reduced through a pump beam by that a λP1 beam of a primary pump is propagated in opposite direction for a communication signal beam λS in the transmission line 12.