Quantum Light from a Whispering Gallery Mode Disk Resonator

TL;DR

This paper demonstrates the generation of quantum light, including intensity squeezing and twin beam correlations, using a crystalline whispering gallery mode disk resonator, highlighting its potential for quantum optics applications.

Contribution

First direct observation of intensity squeezing and twin beam correlations in a whispering gallery mode resonator for quantum light generation.

Findings

Achieved -1.2 dB intensity squeezing of individual beams

Observed -2.7 dB twin beam quantum correlations

Showcased the potential of crystalline resonators in quantum optics

Abstract

Optical parametric downconversion has proven to be a valuable source of nonclassical light. The process is inherently able to produce twin beam correlations along with individual intensity squeezing of either parametric beam, when pumped far above threshold. Here, we present for the first time the direct observation of intensity squeezing of -1.2 dB of each of the individual parametric beams in parametric downconversion by use of a high quality whispering gallery mode disk resonator. In addition we observed twin beam quantum correlations of -2.7 dB with this cavity. Such resonators feature strong optical confinement, and offer tunable coupling to an external optical field. This work exemplifies the potential of crystalline whispering gallery mode resonators in quantum and nonlinear optics and in particular for the generation of quantum light. The simplicity of this device makes the application of quantum light in various fields highly feasible.