Multimode non-classical light generation through the OPO threshold

TL;DR

This paper demonstrates that a multimode optical parametric oscillator can generate non-classical, squeezed vacuum states across multiple modes both below and above threshold, confirmed experimentally with novel phase-locking techniques.

Contribution

It introduces a new experimental method for phase locking and shows multimode non-classical light generation across threshold in an OPO.

Findings

Generation of multimode non-classical states confirmed experimentally.

Non-classical properties are conserved across the oscillation threshold.

A new phase-locking method enables these observations.

Abstract

We show that an Optical Parametric Oscillator which is simultaneously resonant for several modes, either spatial or temporal, generates both below and above threshold a multimode non-classical state of light consisting of squeezed vacuum states in all the non-oscillating modes. We confirm this prediction by an experiment dealing with the degenerate TEM$_{01}$ and TEM$_{10}$ modes. We show the conservation of non-classical properties when the threshold is crossed. The experiment is made possible by the implementation of a new method to lock the relative phase of the pump and the injected beam.