Optical bistability and free carrier dynamics in graphene–silicon photonic crystal cavities

We introduce graphene–silicon hybrid nonlinear devices operating at a few femtojoule cavity circulating energies, including: (1) dual- and single-cavity optical bistability; (2) detailed and broadband switching dynamics, and (3) free-carrier and thermal effects in regenerative oscillations. Sub-wavelength nanostructures confine light in a single mode silicon resonator with high Q/V ratio, enabling strong light interaction with the graphene cladding layer.