Design of transmission optical fiber with a high Raman gain, large effective area, low nonlinearity, and low double Rayleigh backscattering

Designed was the transmission fiber with a high Raman gain, large effective area, low nonlinearity, and low double Rayleigh backscattering (DRBS). Basically the optical signal-to-noise ratio (OSNR) of distributed type Raman amplifier is superior to that of the lumped type Raman amplifier using a high Raman gain fiber such as dispersion compensation fiber. However, much pump power and long length of transmission fiber line are required to acquire a proper gain in the distributed type fiber Raman amplifier. Thus, compositional adjustment on the fiber for optical transmission is of benefit to reduce further the required pump power. In this regard, based on this simulation, the fluorine and germanium co-doped fiber showed a high Raman gain, high OSNR, and low DRBS.