Strongly driven nonlinear quantum optics in microring resonators

TL;DR

This paper provides a comprehensive analytic study of strongly driven nonlinear quantum optics in microring resonators, revealing power-dependent spectral effects, the importance of pump detuning, and new regimes of photon pair generation.

Contribution

It introduces a nonperturbative analytic solution for high-power spontaneous four-wave mixing in microring resonators, highlighting the effects of strong driving and pump detuning.

Findings

Spectral splitting into doublet and quadruplet structures.

Bandwidth narrowing at optical parametric oscillation onset.

Critical pump detuning influences system behavior and photon properties.

Abstract

We present a detailed analysis of strongly driven spontaneous four-wave mixing in a lossy integrated microring resonator side-coupled to a channel waveguide. A nonperturbative, analytic solution within the undepleted pump approximation is developed for a cw pump input of arbitrary intensity. In the strongly driven regime self- and cross-phase modulation, as well as multi-pair generation, lead to a rich variety of power-dependent effects; the results are markedly different than in the low power limit. The photon pair generation rate, single photon spectrum, and joint spectral intensity (JSI) distribution are calculated. Splitting of the generated single photon spectrum into a doublet structure associated with both pump detuning and cross-phase modulation is predicted, as well as substantial narrowing of the generated signal and idler bandwidths associated with the onset of optical parametric oscillation at intermediate powers. Both the correlated and uncorrelated contributions to the JSI are calculated, and for sufficient powers the uncorrelated part of the JSI is found to form a quadruplet structure. The pump detuning is found to play a crucial role in all of these phenomena, and a critical detuning is identified which divides the system behaviour into distinct regimes, as well as an optimal detuning strategy which preserves many of the low-power characteristics of the generated photons for arbitrary input power.