Steady-state generation of negative-Wigner-function light using feedback

TL;DR

This paper introduces a feedback control method to generate and stabilize steady-state light with negative Wigner functions in nonlinear media, enabling continuous production of nonclassical light suitable for systems like exciton-polaritons.

Contribution

The authors develop a feedback-based approach to produce and stabilize steady-state negative-Wigner-function light, overcoming limitations of nonlinearity alone.

Findings

Feedback control significantly enhances Wigner negativities.

Negative Wigner functions are produced continuously at various amplitudes.

Method is applicable to systems with strong natural nonlinearities.

Abstract

We propose a method of producing steady-state coherent light with negative Wigner functions in nonlinear media combined with feedback control. While the nonlinearities are essential to produce the Wigner negativities, this alone is insufficient to stabilize steady-state light with negativities. Using feedback control to control the phase in the cavity, we find that this produces significant total negativities for reasonable experimental parameters. The negative Wigner function is produced continuously and does not appear to be restricted to low-amplitude light. The technique is applicable to systems such as exciton-polaritons, where strong natural nonlinearities are present.