Experimental demonstration of frequency-degenerate bright EPR beams with a self-phase-locked optical parametric oscillator

TL;DR

This paper reports the first experimental demonstration of bright EPR beams generated by a self-phase-locked, frequency-degenerate optical parametric oscillator operating above threshold, showcasing continuous-variable quantum correlations.

Contribution

It introduces a novel method to produce bright, frequency-degenerate EPR beams with phase locking using a birefringent plate inside the cavity.

Findings

Demonstrated continuous-variable EPR correlations between orthogonally polarized beams.

Achieved phase locking at frequency degeneracy with a birefringent plate.

Filtered pump noise to enhance quantum correlations.

Abstract

We report the first experimental observation of bright EPR beams produced by a type-II optical parametric oscillator operating above threshold at frequency degeneracy. The degenerate operation is obtained by introducing a birefringent plate inside the cavity resulting in phase locking. After filtering the pump noise, which plays a critical role, continuous-variable EPR correlations between the orthogonally polarized signal and idler beams are demonstrated.