Effects of ultrafast free-carrier dynamics on frequency comb generation in graphene-based microresonators
Manipulation of the dynamics of cavity solitons, precise control of frequency comb spectra and nonlinear response of microresonators through exploitation of the ultrafast optical properties of graphene can have an immense impact on the technological advancement of on-chip photonic devices. Here, we report that an efficient self-frequency blueshifted frequency comb at optical and near-infrared wavelengths can be achieved owing to the near-instantaneous free-carrier dynamics of graphene in a realistic graphene-covered silicon nitride microresonator. We perform a stability analysis to find the region of stable cavity soliton excitation, which reveals that the nonlinearity of graphene helps in improving the performance of the devices.