Wideband bright soliton frequency comb generation at optical telecommunication wavelength in a thin SiN film

TL;DR

This paper demonstrates a novel dispersion-engineering method in thin-film silicon nitride microresonators to generate wideband bright soliton frequency combs at telecommunication wavelengths, enhancing bandwidth via soliton Cherenkov radiation.

Contribution

It introduces a new approach using coupling-dispersion in coupled microresonators for dispersion engineering at 1.55 μm, enabling wideband soliton comb generation.

Findings

Achieved anomalous dispersion at 1.55 μm for Kerr-comb generation.

Enhanced comb bandwidth through soliton-induced Cherenkov radiation.

Validated the approach with numerical simulations.

Abstract

Bright-soliton frequency comb generation in a thin-film silicon nitride (SiN) microresonator at optical telecommunication wavelengths is numerically demonstrated using our recently developed approach for dispersion-engineering by virtue of coupling-dispersion between two coupled microresonators. By coupling two identical resonators through an asymmetric Mach-Zehnder structure, sinusoidal splitting of the resonance frequencies can be achieved. This enables the engineering of the dispersion of the resulting modes of the coupled structure. Using this approach, anomalous dispersion of the resonant modes can be achieved at the pumping wavelength (which is selected to be the optical telecommunication wavelength, i.e., 1.55 $\mu m$) to enable Kerr-comb generation. In addition, by utilizing soliton-induced Cherenkov radiation in the coupled-resonator structure, we can increase the bandwidth of the resulting Kerr-comb signal.