We model optical parametric oscillation in ring cavities with two-photon
absorption, focusing on silicon at 1.55μm. Oscillation is possible if
free-carrier absorption can be mitigated; this can be achieved using carrier
sweep-out in a reverse-biased p-i-n junction to reduce the carrier lifetime. By
varying the pump power, detuning, and reverse-bias voltage, it is possible to
generate frequency combs in cavities with both normal and anomalous dispersion
at a wide range of wavelengths including 1.55μm. Furthermore, a
free-carrier self-pulsing instability leads to rich dynamics when the carrier
lifetime is sufficiently long.Comment: 7 pages, 12 figures. Presented at 2017 International Topical Meeting
on Microwave Photonics. Submitted to Journal of Lightwave Technolog