Novel architecture for ultra-stable micro-ring resonator based optical frequency combs

TL;DR

This paper introduces a new microcavity resonator design for optical frequency combs that enables stable, wide bandwidth comb generation without thermal locking, using a self-locked scheme with CMOS-compatible microring resonators.

Contribution

A novel geometry and self-locked scheme for microcavity-based OPOs that achieve stable, wide bandwidth combs without thermal locking.

Findings

Achieved stable oscillation without shutdown or self-termination.

Produced wide bandwidth (>300nm) combs.

Oscillation at the microcavity resonance FSR.

Abstract

We report a novel geometry for OPOs based on nonlinear microcavity resonators. This approach relies on a self-locked scheme that enables OPO emission without the need for thermal locking of the pump laser to the microcavity resonance. By exploiting a CMOS-compatible microring resonator, we achieve oscillation with a complete absence of shutting down, or self-terminating behavior, a very common occurrence in externally pumped OPOs. Further, this scheme consistently produces very wide bandwidth (>300nm, limited by our experimental set-up) combs that oscillate at a spacing of the FSR of the micro cavity resonance.