Towards energy-efficient optical networks: adaptive launch power optimization in multi-channel WDM systems

Abstract In wavelength division multiplexed (WDM) optical communication systems, when all the channels are allocated with equal launch power, it often leads to suboptimal performance because of the fiber nonlinearities, inter-channel interference, and amplifier noise. In this paper, we proposed a system that works on an adaptive launch power allocation technique for all of the four-channel WDM optical transmission. The system operates at four different wavelengths corresponding to 193.1–193.4 THz, each with a data rate of 10 Gb/s per channel over a standard single-mode fiber link. At first, a fixed equal launch power of 5 dB m per channel is considered as a baseline configuration. The results demonstrate that all four channels exhibit distinct optimal power levels because of the channel interactions and nonlinear effects. For example, Channel 3 achieves its optimum performance at approximately 1 dBm, where the Q-factor reaches about 10.4 with BER in the order of 10 −26 . Compared with the fixed launch power system’s configuration, the adaptive launch power allocation scheme significantly reduces the total transmitted optical power while maintaining or improving system performance. The proposed work indicates that adaptive launch power allocation can enhance energy efficiency and transmission quality in WDM optical networks.