Simulations and Experiments on Polarisation Squeezing in Optical Fibre

TL;DR

This paper explores polarisation squeezing in optical fibres, combining experiments and advanced quantum simulations to understand how various noise effects influence squeezing efficiency across different conditions.

Contribution

It introduces comprehensive quantum dynamical simulations including Raman effects and phase noise, providing new insights into optimizing fibre length and input energy for maximum squeezing.

Findings

Excess phase noise impacts low-energy squeezing.

Raman effects deteriorate squeezing at high energies.

Optimal fibre length for maximum squeezing identified.

Abstract

We investigate polarisation squeezing of ultrashort pulses in optical fibre, over a wide range of input energies and fibre lengths. Comparisons are made between experimental data and quantum dynamical simulations, to find good quantitative agreement. The numerical calculations, performed using both truncated Wigner and exact $+P$ phase-space methods, include nonlinear and stochastic Raman effects, through coupling to phonons variables. The simulations reveal that excess phase noise, such as from depolarising GAWBS, affects squeezing at low input energies, while Raman effects cause a marked deterioration of squeezing at higher energies and longer fibre lengths. The optimum fibre length for maximum squeezing is also calculated.