Impact of nonlinear losses on the performance of InGaAsP-on-insulator ring resonators

We analyze, for the first time, to our knowledge, ring resonators on InGaAsP () on (InGaAsP-on-insulator or InGaAsP-OI) platform for frequency comb generation at 1550 nm. We theoretically investigate the impact of nonlinear losses such as two-photon absorption (TPA) and free-carrier absorption (FCA) on the generation of frequency combs in ring resonators made on this platform. We demonstrate that FCA is the primary loss mechanism in an InGaAsP-OI ring resonator at 1550 nm, hindering the observation of frequency comb generation. This issue can be mitigated by reducing the free-carrier lifetime through the introduction of a biased p–n junction.