Dispersion Engineered C-band Parametric Oscillator Based on Silicon Concentric Microresonators

Integrated optical nonlinearities have spawned many new technologies such as optical parametric oscillators and microcombs. Despite remarkable achievements, optical parametric oscillation (OPO) and microcomb generation remain challenging for foundry-available silicon photonics. Silicon-photonic platform provides mature CMOS manufacturing process and relatively high nonlinear coefficient. However, the nonlinear absorption at near-infrared telecommunication band hinders the effective nonlinear response on silicon photonics. In addition, the 220 nm thick Si layer is unsuitable for anomalous dispersion waveguides, which is necessary for OPO process. In this work, a concentric microresonator with the PIN doping structure is designed to solve these two problems. Under reverse bias on the designed PIN structure, the generated free carriers are effectively migrated to weaken the free carrier absorption. Local anomalous dispersion is induced by the designed concentric structure. Optical parametric oscillation is theoretically analyzed and 10 OPO sidebands are experimentally generated with a single pump. Our design verifies the ability of dispersion engineered nonlinear oscillators in C-band on foundry-available silicon photonic platform.