Novel graphene-based photonic devices for efficient light control and manipulation

A novel graphene-based photonic device with two graphene monolayers sandwiched by two vertically-stacked microring resonators has been proposed. The integration of graphene allows an efficient tuning of electronic and optical properties of the resonant cavity by applying low values of voltage, minimizing the values of switching energy and switching time. This feature and the small footprint demonstrate the suitability of the proposed resonant cavity to be used as an efficient phase-shifter or a delay line. A detailed analysis of the state-of-the-art of the optical microcavities used to control and manipulate the properties of light has been also discussed to compare the performance of the proposed graphene-based vertically-stacked microring resonators with the results already proposed in literature. A maximum group delay τ_g = 360 ps with a tuning range Δτ_g = 230 ps, and a switching energy E_switch = 26 pJ have been calculated, which confirm a high performance of the graphene-based resonant cavity with an ultra-compact footprint of 1600 μm².