Segmented Power Optimization in C+L+S Ultra-Wideband Fiber Transmission Systems

—Ultra-wideband fiber transmission systems are essential for meeting the growing demand for high-capacity networks. However, existing power optimization strategies, such as the slope-offset model, struggle to achieve sufficiently flat SNR profiles, especially in the L band. To address this limitation, we propose a segmented power allocation method that models the L-band power distribution as multiple linear segments, each controlled by the offset and slope parameters. This approach is evaluated under three optimization goals: GSNR flatness for per-channel rates of 400 Gb/s and 800 Gb/s, and total system throughput maximization. Experimental results show that finer segmentation of the L band markedly improves GSNR flatness, achieving performance close to full per-channel optimization while greatly reducing computational complexity. However, in throughput-driven optimization, the segmentation approach offers only limited enhancement.