Optimum optical fiber design for a DRA-based DWDM transmission system

This paper describes the distributed Raman amplification (DRA) transmission characteristic in an optical fiber both numerically and experimentally. The paper clarifies the relationship between optical fiber parameters and DRA transmission performance with regard to the signal-to-noise ratio (SNR) characteristics and nonlinear impairments. These relationships can be successfully discussed, taking account of various fiber parameters, including Raman gain efficiency, the attenuation coefficient at signal and pump wavelengths, the Rayleigh scattering coefficient, and the nonlinear refractive index, as a function of the relative index difference in an optical fiber. An example of an optimum fiber design for a DRA-based dense-wavelength-division-multiplexing (DWDM) transmission system is also discussed.