# Single pump, parametric amplification in randomly-birefringent, unidirectionally spun fibers

## TL;DR

This paper investigates how polarization mode dispersion affects broadband and narrowband fiber parametric amplifiers, revealing that nonlinear polarization rotation and fiber spinning influence gain and alignment.

## Contribution

It provides a systematic numerical analysis of polarization effects in unidirectionally spun fibers, highlighting the interplay between polarization rotation, dispersion, and gain.

## Key findings

- Nonlinear polarization rotation increases gain randomness.
- Unidirectional spinning enhances signal-pump alignment.
- High polarization mode dispersion reduces gain despite improved alignment.

## Abstract

A systematic study of the effects of polarization mode dispersion on broad-band and narrow-band, single pump, fiber parametric amplifiers is realized through numerical solutions of the equations governing the interaction. The nonlinear polarization rotation is shown to be a relevant effect that can increase gain randomness when it mixes with polarization mode dispersion. In unidirectionally spun fibers the signal-pump alignment can be highly increased and the gain enhanced. However, in spite of the enhanced alignment, large polarization mode dispersion phase-mismatches the interaction and the gain decreases to zero.