Deformed square resonator lasers for optical frequency comb generation

TL;DR

This paper introduces deformed square resonator lasers with circular sides to enhance mode Q factors and enable dual-mode emission, leading to optical frequency comb generation via four-wave mixing.

Contribution

It proposes a novel deformed square resonator design with circular sides, demonstrating improved mode Q factors and dual-mode emission for optical frequency comb generation.

Findings

Enhanced mode Q factors in deformed square resonators.

Successful dual-mode lasing with different wavelength intervals.

Generation of optical frequency combs via four-wave mixing.

Abstract

Deformed square resonators with the flat sides replaced by circular sides are proposed and demonstrated to enhance mode Q factors and adjust transverse mode intervals using the regular ray dynamic analysis and numerical simulations. Dual-transverse-mode emissions due to the ultrahigh-Q factors with different wavelength intervals are realized experimentally for AlGaInAs/InP circular-side square microlasers, and the stationary condition of the dual-mode emission is satisfied because the high-Q confined modes have totally different mode numbers. Furthermore, optical frequency combs are generated using the dual-mode lasing microlaser as a seeding light source by cascaded four-wave mixing in a highly nonlinear optical fiber.