Tunable degree of polarization in a Figure-8 fiber laser

TL;DR

This paper experimentally investigates how the degree of polarization in a Figure-8 fiber laser can be controlled by tuning system parameters, with a theoretical mapping explaining the polarization dynamics.

Contribution

It introduces a mapping to evaluate polarization evolution and demonstrates how tuning parameters enhances polarization stability in the laser.

Findings

Degree of polarization can be increased by tuning parameters.

The mapping predicts polarization stability regions.

Nonlinear effects influence polarization dynamics.

Abstract

We experimentally study a fiber loop laser in the Figure-8 configuration, and explore the dependency of the degree of polarization on controlled parameters. To account for the experimental observations, a mapping is derived to evaluate the polarization time evolution. Nonlinearity induced by Kerr effect and gain saturation gives rise to rich dynamics. We find that degree of polarization can be increased by tuning the system into a region where the mapping has a locally stable fixed point.