Effect of Pumps Power Combinations Versus Wavelength Allocation on Raman Amplifier Performance in Dwdm Transmission System

This paper investigates optimization and power/wavelength allocation of a RAMAN amplifier designed for Dense Wavelength Division Multiplexed (DWDM) Systems consisting of forty channels with frequency spacing 25 GHz at the edge of L and U wavelength bands (185 THz - 185.975 THz). Four pumps used in the forward direction with wavelengths at 1500, 1525, 1565, 1574 nm and four pumps in the backward direction with wavelengths at 1435, 1460, 1474, 1489 nm are used. The forward pumps power distribution and backward pump power distribution combinations are investigated for the Raman amplifier best performance. The performance of the system includes overall gain and flatness. The location of the wavelength in the forward or backward direction and the power distribution among each wavelength in an ascending or descending order is also investigated. It is found that the red shifted pump wavelengths should be used in the forward direction and the blue shifted pump wavelengths should be used in the backward direction for best performance.