Artificial Cnoidal Wave Breathers in Optical Microresonators

TL;DR

This paper introduces a novel bichromatic pumping method in optical microresonators to generate artificial cnoidal wave breathers and diverse microcombs, expanding understanding of breathing phenomena in driven nonlinear systems.

Contribution

It proposes and experimentally demonstrates a new bichromatic pumping scheme to create artificial breathers and reconfigurable microcombs in silicon nitride microresonators.

Findings

Discovery of artificial cnoidal wave breathers in microresonators

Microcombs with tunable line spacing from 2 to 17 times FSR

Theoretical modeling using bichromatic pumping Lugiato-Lefever equation

Abstract

Breathers are localized structures that undergo a periodic oscillation in their duration and amplitude. Optical microresonators, benefiting from their high quality factor, provide an ideal test bench for studying the breathing phenomena. In the monochromatically pumped microresonator system, intrinsic breathing instabilities are widely observed in the form of temporal dissipative Kerr solitons which only exist in the effectively red detuned regime. Here, we proposed a novel bichromatic pumping scheme to create compulsive breathing microcombs via respectively distributing two pump lasers at the effectively blue and red detuned side of a single resonance. We experimentally discover the artificial cnoidal wave breathers and molecular crystal-like breathers in a chip-based silicon nitride microresonator, and theoretically describe their intriguing temporal dynamics based on the bichromatic pumping Lugiato-Lefever equation. In particular, the corresponding breathing microcombs exhibit diverse comb line spacing ranging from 2 to 17 times of the free spectral range of the resonator. Our discovery not only provides a simple and robust method to produce microcombs with reconfigurable comb line spacing, but also reveals a new type of breathing waves in driven dissipative nonlinear systems.