Slow-light enhanced frequency combs and dissipative Kerr solitons in silicon coupled-ring microresonators in the telecom band

Abstract: We propose a system of coupled microring resonators for the generation frequency combs and dissipative Kerr solitons in silicon at telecommunication frequencies. By taking advantage of structural slow-light, the effective non-linearity of the material is enhanced, thus relaxing the requirement of ultra-high quality factors that currently poses a major obstacle to the realization of silicon comb devices. We demonstrate a variety of frequency comb solutions characterized by threshold power in the 10-milliwatt range and a small footprint of $0.1$ mm$^2$, and study their robustness to structural disorder. The results open the way to the realization of low-power compact comb devices in silicon at the telecom band.