Near‐Infrared Soliton Crystal Generation in Silicon Resonators

Abstract

Dissipative Kerr solitons (DKSs) provide coherent, low‐noise, multi‐wavelength light sources for various photonic applications. However, the realization of near‐infrared DKS in silicon has not been experimentally reported due to severe two‐photon absorption (TPA) and free‐carrier absorption (FCA). Here, we report the first experimental evidence for deterministic low‐noise soliton‐crystal (SC) states in monolithic silicon resonators operating at telecom wavelengths (1.55 µm). By synergistically combining an active lateral p–i–n junction for rapid free‐carrier extraction with precise spatial‐mode dispersion engineering, we overcome the nonlinear loss in silicon to achieve robust parametric oscillation. With this strategy, an avoided mode crossing provides deterministic pathways to SC states with 2‐FSR and 3‐FSR comb spacing, characterized by sech 2 envelope, distinct power steps and low radiofrequency (RF) noise. Separately, a near‐zero‐dispersion resonator produces broadband optical parametric oscillation (OPO) with cascaded sub‐comb formation spanning over 300 nm across the S, C, and L bands, distinct from the SC states. These results demonstrate telecom‐band nonlinear‐photonic comb generation in monolithic silicon, with potential for future co‐integration with silicon photonic and CMOS components.