Observation of robust polarization squeezing via the Kerr nonlinearity in an optical fibre

TL;DR

This paper presents a simple, robust all-fibre setup for polarization squeezing using the optical Kerr effect, achieving over 5 dB of stable squeezing without adjustments, suitable for various quantum photonic applications.

Contribution

The authors developed a passive, all-fibre polarization squeezing setup that is stable and easy to operate, overcoming sensitivity issues of previous methods.

Findings

Achieved over 5 dB of squeezing with the new setup

Demonstrated long-term stability without adjustments

Investigated effects of pulse duration and power on squeezing

Abstract

Squeezed light is one of the resources of photonic quantum technology. Among the various nonlinear interactions capable of generating squeezing, the optical Kerr effect is particularly easy-to-use. A popular venue is to generate polarization squeezing, which is a special self-referencing variant of two-mode squeezing. To date, polarization squeezing generation setups have been very sensitive to fluctuations of external factors and have required careful tuning. In this work, we report on a development of a new all-fibre setup for polarization squeezing generation. The setup consists of passive elements only and is simple, robust, and stable. We obtained more than 5 dB of directly measured squeezing over long periods of time without any need for adjustments. Thus, the new scheme provides a robust and easy to set up way of obtaining squeezed light applicable to different applications. We investigate the impact of pulse duration and pulse power on the degree of squeezing.