Mode-Dependent Loss and Gain: Statistics and Effect on Mode-Division Multiplexing

TL;DR

This paper analyzes the statistical behavior of mode-dependent loss and gain in multimode fiber systems, revealing their impact on channel capacity and performance limits in mode-division multiplexing.

Contribution

It introduces a statistical model for MDL based on eigenvalue distributions and studies its effect on channel capacity in mode-division multiplexing systems.

Findings

Eigenvalue distribution of MDL follows zero-trace Gaussian unitary ensemble.

MDL significantly affects average and outage capacities.

Strong mode coupling regime is critical for practical long-haul transmission.

Abstract

In multimode fiber transmission systems, mode-dependent loss and gain (collectively referred to as MDL) pose fundamental performance limitations. In the regime of strong mode coupling, the statistics of MDL (expressed in decibels or log power gain units) can be described by the eigenvalue distribution of zero-trace Gaussian unitary ensemble in the small-MDL region that is expected to be of interest for practical long-haul transmission. Information-theoretic channel capacities of mode-division-multiplexed systems in the presence of MDL are studied, including average and outage capacities, with and without channel state information.