Detailed investigation on gain-clamping characteristics of ultralong fiber Raman laser using FBGs

作者:Rao, Yun Jiang*; Jia, Xin Hong; Li, Li; Ran, Zeng Ling
来源:Journal of the Optical Society of America B-Optical Physics, 2009, 26(7): 1334-1340.
DOI:10.1364/JOSAB.26.001334

摘要

A comprehensive theoretical model to explore the gain-clamping characteristics of ultralong fiber Raman lasers (UL-FRL) based on fiber Bragg gratings (FBGs) in which the amplified spontaneous emission (ASE), double Rayleigh backscattering (DRB), and modulation-instability- (MI-) induced spectral broadening effect are considered to be self-consistent. The experimental results are used to validate the theoretical model. The influences of pump configuration and fiber length on dynamic range, noise performance, and nonlinear impairment are discussed in detail. The result shows that an ultralong transmission of up to similar to 155 km by using a total of 1.38 W Raman pump power accompanied by gain clamping can be achieved; a backward pump is helpful to obtain a wider dynamic range and to avoid nonlinear impairment, but it is harmful to noise performance; and shorter fiber length is helpful to obtain both optimized gain clamping and weakened nonlinear impairment. Such an UL-FRL has considerable potential to realize both ultralong signal transmission and gain clamping to overcome signal distortion and interchannel cross talk in dense wavelength division multiplexing (DWDM) networks.