Optimal Position of Isolator to Suppress Double Rayleigh Backscattering Noise in Fiber Raman Amplifiers

Wenning JIANG  Jianping CHEN  Junhe ZHOU  

IEICE TRANSACTIONS on Electronics   Vol.E88-C   No.4   pp.721-724
Publication Date: 2005/04/01
Online ISSN: 
DOI: 10.1093/ietele/e88-c.4.721
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Lasers, Quantum Electronics
fiber Raman amplifier,  double Rayleigh backscattering,  

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In this paper, amplified double Rayleigh backscattering noise (DRB) in the optical fiber Raman amplifier is analyzed. Expressions are present for both forward pumping and backward pumping schemes, respectively. Calculation is performed to show the effective suppression of DRB noise by employing an optical isolator. The best isolator position is determined as 13 km away from the signal input end for forward pumping, and 9 km from the output end for backward pumping. The best position is found insensitive to the fiber length, pump power, and signal power. When the isolator is on the best position, the DRB noise can be reduced by almost 2 to 3 orders.