Tunable Squeezing Using Coupled Ring Resonators on a Silicon Nitride Chip

TL;DR

This paper demonstrates a method to continuously tune the squeezing level in a silicon nitride double-ring resonator using electrically controlled microheaters, enabling adjustable quantum squeezing for sensing applications.

Contribution

It introduces a tunable on-chip squeezing device based on coupled silicon nitride microring resonators with electrical control, achieving significant variation in squeezing levels.

Findings

Squeezing level tuned from 0.5 dB to 2 dB

On-chip squeezing factor varied from 0.9 dB to 3.9 dB

Electrical control via microheaters effectively modulates coupling

Abstract

We demonstrate continuous tuning of the squeezing level generated in a double-ring optical parametric oscillator by externally controlling the coupling condition using electrically controlled integrated microheaters. We accomplish this by utilizing the avoided crossing exhibited by a pair of coupled silicon nitride microring resonators. We directly detect a change in the squeezing level from 0.5 dB in the undercoupled regime to 2 dB in the overcoupled regime, which corresponds to a change in the generated on-chip squeezing factor from 0.9 dB to 3.9 dB. Such wide tunability in the squeezing level can be harnessed for on-chip quantum enhanced sensing protocols which require an optimal degree of squeezing.