Homodyne locking of a squeezer

TL;DR

This paper introduces a novel homodyne locking method for stabilizing an OPO-based squeezed-vacuum source and its laser, enabling automatic phase-locking and sub-QNL frequency discrimination with simplicity and cost-effectiveness.

Contribution

The paper presents a new homodyne locking technique that simplifies frequency stabilization and phase locking of squeezed-vacuum sources, with advantages over traditional methods.

Findings

Successfully implemented the homodyne locking technique.

Achieved automatic phase-locking of subsequent homodyne measurements.

Demonstrated sub-QNL frequency discrimination capability.

Abstract

We report on the successful implementation of a new approach to locking the frequencies of an OPO-based squeezed-vacuum source and its driving laser. The technique allows the simultaneous measurement of the phase-shifts induced by a cavity, which may be used for the purposes of frequency-locking, as well as the simultaneous measurement of the sub-quantum-noise-limited (sub-QNL) phase quadrature output of the OPO. The homodyne locking technique is cheap, easy to implement and has the distinct advantage that subsequent homodyne measurements are automatically phase-locked. The homodyne locking technique is also unique in that it is a sub-QNL frequency discriminator.