Optimal power allocation in nonlinear MDM‐WDM systems using Gaussian noise model

Mode-division multiplexing (MDM) using few-mode fibre (FMF) has received increasing attention to address the exponential growth of data traffic in long-haul optical communication systems. Also, combining MDM with wavelength-division (WDM) is a promising approach for dramatically growing transmission capacity such However, major barrier this regard FMF nonlinear effects, which can significantly reduce link performance. In paper, order alleviate we focus on power allocation links by optimizing input each WDM channel spatial mode, leads maximizing total and also minimum signal noise ratio (SNR) margin. The nonlinearity been already modelled as Gaussian (GN) no closed-form formulation developed so far. Here, derive GN model problem verify it comparing integral-form split-step Fourier method. approach, an optimal independently determined mode maximization SNR margin convex forms. performance different including single fibre-WDM, MDM-single channel, MDM-WDM are compared computer simulations. These systems comprehensively investigated equal/non-equal required well flat/non-flat amplifier gain scenarios. It shown that optimized significant enhancement scheme best equal allocation. Furthermore, improvement much more non-equal non-flat scenarios, showing efficiency established practical links.