Tunable Degenerate Optical Parametric Oscillation with Coupled Microresonators

Microresonator-based degenerate optical parametric oscillation (DOPO) has recently been explored as a compelling platform for all-optical computing and quantum information applications such as truly random number generation and the production of squeezed states of light. Emerging research has highlighted the potential of coupled microresonators, or photonic molecules, as a novel avenue for spectral engineering, unlocking an extra degree of freedom for the optimization of four-wave mixing interactions. Here, we demonstrate a single tunable DOPO within the coupled modes of a silicon nitride triplet-state photonic molecule. Our design introduces a distinctive mechanism for spectral engineering, using microheaters to individually tune the resonance spectral positions, thus enabling dynamic local dispersion control within the coupled modes. We successfully generated a DOPO signal with active efficiency control and explored the optical mode spacing in the tens of gigahertz range to use native phase-locked optical pumps driven by a radio frequency source.