# Simulation of Nonlinear Signal Propagation in Multimode Fibers on Multi-GPU Systems

## TL;DR

This paper presents a GPU-accelerated simulation framework for nonlinear signal propagation in multimode fibers supporting up to 120 modes, addressing computational challenges for large-scale mode-division multiplexing systems.

## Contribution

It introduces a multi-GPU implementation for simulating nonlinear MDM fiber systems with many modes, evaluating GPU communication approaches and performance for large-scale simulations.

## Key findings

- Efficient multi-GPU simulation of nonlinear multimode fiber propagation.
- Performance analysis of GPU communication strategies.
- Impact assessment of nonlinear effects on high-mode-count MDM systems.

## Abstract

Mode-division multiplexing (MDM) is seen as a possible solution to satisfy the rising capacity demands of optical communication networks. To make MDM a success, fibers supporting the propagation of a huge number of modes are of interest. Many of the system aspects occurring during the propagation can be evaluated by using appropriate models. However, fibers are a nonlinear medium and, therefore, numerical simulations are required. For a large number of modes, the simulation of the nonlinear signal propagation leads to new challenges, for example regarding the required memory, which we address with an implementation incorporating multiple GPU-accelerators. Within this paper, we evaluate two different approaches to realize the communication between the GPUs and analyze the performance for simulations involving up to 8 Tesla GPUs. We show results for a MDM transmission system utilizing the extremely large but practically very relevant number of 120 spatial modes as an application example and analyze the impact of the nonlinear effects on the transmitted signals.