Configuration of the optical transmission line using stimulated Raman scattering for signal light amplification

Expansion of a repeater spacing of optical transmission line is investigated using forward stimulated Raman scattering generated by a 1.34-μm Nd:YAG laser to amplify the signal light. Achievable repeater spacing at the 1.42-μm wavelength transmission is numerically estimated on the basis of coupled power equations and experimentally obtained Raman gain for various core-cladding index difference. A transmission distance of more than 200 km is predicted for an input signal light power of 100 μw and a pump power of 200 mW using a fiber with a relative index difference of 1 percent.