Parsing Squeezed Light into Polarization Manifolds

TL;DR

This paper explores polarization squeezing in quantum states with varying photon numbers, using a novel approach to analyze the Stokes vector in different excitation manifolds, providing deeper insights into quantum polarization properties.

Contribution

It introduces a method to analyze polarization squeezing by separately determining the Stokes vector for each excitation manifold, extending traditional fixed-photon-number analysis.

Findings

Experimental determination of Stokes vectors for different photon number states

Deeper understanding of polarization squeezing in indefinite photon number states

Mapping of squeezing properties onto Poincare space using Husimi Q function

Abstract

We investigate polarization squeezing in squeezed coherent states with varying coherent amplitudes. In contrast to the traditional characterization based on the full Stokes parameters, we experimentally determine the Stokes vector of each excitation manifold separately. Only for states with a fixed photon number do the methods coincide; when the photon number is indefinite, our approach gives a richer and deeper description. By capitalising on the properties of the Husimi Q function, we map this notion onto the Poincare space, providing a full account of the measured squeezing.