Physics

Laser linewidth

Laser

Nonlinear optics

Phase noise

OPOS

Resonator

Optics

Frequency comb

Photonics

Nanophotonics

Optical parametric oscillator

Optoelectronics

Wavelength

Quantum optics

Optica

Optical parametric oscillators (OPOs) have been widely used for decades as tunable, narrow-linewidth, and coherent light sources for reaching long wavelengths and are attractive for applications such as quantum random number generation and Ising machines. To date, waveguide-based OPOs have suffered from relatively high thresholds on the order of hundreds of milliwatts. With the advance in integrated photonic techniques demonstrated by high-efficiency second-harmonic generation in aluminum nitride (AlN) photonic microring resonators, highly compact and nanophotonic implementation of parametric oscillation is feasible. Here we employ phase-matched AlN microring resonators to demonstrate low-threshold parametric oscillation in the telecom infrared band with an on-chip efficiency up to 17% and milliwatt-level output power. A broad phase-matching window is observed, enabling tunable generation of signal and idler pairs over a 180 nm bandwidth across the C band. This result establishes an important milestone in integrated nonlinear optics and paves the way towards chip-based quantum light sources and tunable, coherent radiation for spectroscopy and chemical sensing.

On-chip χ<sup>(2)</sup> microring optical parametric oscillator

On-chip χ(2) microring optical parametric oscillator

On-chip χ⁽²⁾ microring optical parametric oscillator