Mechanically actuated Kerr soliton microcombs

TL;DR

This paper introduces a mechanically actuated Kerr soliton microcomb system that simplifies operation by enabling direct initiation and stabilization without complex pump laser control, broadening practical applications.

Contribution

It demonstrates a novel mechanically actuated approach to initiate and stabilize Kerr soliton microcombs, reducing reliance on sophisticated pump laser tuning.

Findings

Achieved a 15 GHz microwave repetition rate microcomb.

Enabled direct soliton initiation and long-term stabilization.

Reduced complexity for practical deployment outside labs.

Abstract

Mode-locked ultrashort pulse sources with a repetition rate of up to several tens of gigahertz greatly facilitate versatile photonic applications such as frequency synthesis, metrology, radar, and optical communications. Dissipative Kerr soliton microcombs provide an attractive solution as a broadband, high-repetition-rate compact laser system in this context. However, its operation usually requires sophisticated pump laser control to initiate and stabilize the soliton microcombs, particularly in millimeter-sized ultrahigh-Q whispering-gallery resonators. Here, we realize a mechanically actuated soliton microcomb oscillator with a microwave repetition rate of 15 GHz. This enables direct soliton initiation, long-term stabilization, and fine tuning, where the operation now lifts the prerequisite pump laser tunability that must be relaxed if the technology is to be widely used outside the laboratory environment. We reveal the prospects for using this method with a wide range of applications that would benefit from mechanical soliton actuation such as optical clocks, spectral extension, and dual-comb spectroscopy.