Signal and Backward Raman Pump Power Optimization in Multi-Band Systems Using Fast Power Profile Estimation

This paper presents an efficient numerical method for calculating spatial power profiles of both signal and pump with significant Interchannel Stimulated Raman Scattering (ISRS) and backward Raman amplification in multiband systems. This method was evaluated in the optimization of a C+L+S/C+L+S+E 1000km link, employing three backward Raman pumps, by means of a closed-form EGN model (CFM6). The results show a 100x computational speed increase, enabling deep optimization which made it possible to obtain very good overall system performance and flat GSNR.

An Algorithm to Speed up the Spatial Power Profile Calculation in Backward Raman Amplified Systems

As data transmission demands grow, long-haul optical transmission links face increasing pressure to increase their throughput. Expanding usable bandwidth through Ultra-Wide Band (UWB) systems has become the primary strategy for increasing transmission capacity. However, UWB systems present challenges, such as the reliance on backward Raman amplification and the complications posed by inter-channel stimulated Raman scattering (ISRS), which causes uneven signal propagation across bands. To address these issues, accurate and efficient physical models are required for real-time optimization, which rely on the knowledge of the power profile. This paper develops a novel, more efficient method for computing the power profile of signals and pumps, utilizing the integral form of the equations with matrix-based approximations. The algorithm achieves up to a thirty-fold average speed increase over conventional approaches while maintaining an error margin under 0.05 dBm. These results represent a significant step forward towards reducing optimization times and enabling more extensive studies in ultra-wide band long haul optical transmission, further facilitating research and commercialization of UWB systems, in an effort to address the growing demand for higher throughput.