Enhanced thermo-optic nonlinearities in a MoS₂-on-silicon microring resonator

We experimentally investigated the thermal nonlinearity in a MoS₂-on-silicon microring resonator. In the hybrid MoS₂-on-silicon microring resonator, there was a threefold increase in the resonance shift rate as input optical power increased. The effective photothermal coefficient of the MoS₂-on-silicon resonator was enhanced to 4.7 × 10^-15 m² W^-1. The enhancement can be attributed to the presence of defect states of the MoS₂ film, leading to additional absorption of light and enhanced heating, which changed the effective refractive index of the resonator. Efficient thermal bistability was observed in the resonator.