Tunable telecom to mid-infrared optical parametric oscillation via microring-based $\chi^{(3)}$ nonlinearities

TL;DR

This paper demonstrates a tunable, chip-scale optical parametric oscillator based on crystalline aluminum nitride microrings, capable of generating large frequency shifts from telecom to mid-infrared bands with high tunability.

Contribution

It introduces a novel $ ext{chi}^{(3)}$-based OPO in crystalline aluminum nitride microrings with large frequency shifts and versatile tuning methods, advancing integrated light source technology.

Findings

Achieved 65.5 THz frequency shift between telecom and mid-infrared bands.

Demonstrated wavelength tunability of 10, 1, and 0.1 THz via different tuning methods.

Observed evolution into localized frequency comb lines at high pump powers.

Abstract

Optical parametric oscillation (OPO) with far-shifted frequency sidebands has attracted significant interests in precision spectroscopy and quantum information processing. Microresonator based OPO sources hold the advantages of miniaturized footprint and versatile dispersion engineering. Here we demonstrate large-frequency-shifted $\chi^{(3)}$-based OPO from crystalline aluminum nitride microrings pumped at $\sim$2 $\mu$m in the normal dispersion regime. OPO in the telecom and mid-infrared bands with a frequency separation of 65.5 THz is achieved. The OPO frequency can be agilely tuned in the ranges of 10, 1 and 0.1 THz respectively by tailoring the microring dimensions, shifting the pump wavelength, and controlling the chip temperature. At high intracavity pump powers, the OPO sidebands further evolve into localized frequency comb lines. Such telecom to mid-infrared OPO with flexible wavelength tunability will lead to enhanced chip-scale light sources.