Dissipative Kerr solitons in photonic molecules

TL;DR

This paper explores the nonlinear dynamics of coupled microresonators, demonstrating the formation of dissipative Kerr solitons in photonic molecules, leading to high-quality, efficient microcombs with potential applications in various optical fields.

Contribution

It introduces the concept of dissipative Kerr solitons in photonic molecules formed by coupled microresonators, a novel phenomenon in nonlinear optics.

Findings

Photonic molecules support self-enforcing solitary waves.

Microcombs exhibit high spectral flatness and efficiency.

Operable with low laser power of a few milliwatts.

Abstract

Many physical systems display quantized energy states. In optics, interacting resonant cavities show a transmission spectrum with split eigenfrequencies, similar to the split energy levels that result from interacting states in bonded multi-atomic, i.e. molecular, systems. Here, we study the nonlinear dynamics of photonic diatomic molecules in linearly coupled microresonators and demonstrate that the system supports the formation of self-enforcing solitary waves when a laser is tuned across a split energy level. The output corresponds to a frequency comb (microcomb) whose characteristics in terms of power spectral distribution are unattainable in single-mode (atomic) systems. Photonic molecule microcombs are coherent, reproducible, and reach high conversion efficiency and spectral flatness whilst operated with a laser power of a few milliwatts. These properties can favor the heterogeneous integration of microcombs with semiconductor laser technology and facilitate applications in optical communications, spectroscopy and astronomy.