Observation of Robust Polarization Squeezing via the Kerr Nonlinearity in an Optical Fiber

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, a development of a new all‐fiber setup for polarization squeezing generation is reported. The setup consists of passive elements only and is simple, robust, and stable. More than 5 dB of directly measured squeezing is obtained 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. The impact of pulse duration and pulse power on the degree of squeezing is investigated. Squeezed light is a photonic quantum technology resource. The optical Kerr effect is often used to generate polarization squeezing. Such setups have been very sensitive to fluctuations of external factors. Here, a new all‐fiber very stable passive setup generating more than 5 dB of squeezing is presented. It provides a robust and easy way of obtaining squeezed light for applications.