Design of an Energy Efficient Optical Delay Line Using Graphene in Photonic Crystal Waveguide

An energy efficient design of an optical delay line by introducing graphene in the photonic crystal waveguide (PCW) is proposed. It is observed that PCW can slow down the guided light utilizing the unique optical properties of graphene. The proposed device comprises of two designs; in first design Graphene is coated at the core, and in second design at cladding area of PCW respectively. The maximum group delay of 80 picoseconds and 88 picoseconds have been observed in the core and cladding region respectively even at a low power consumption of < ∼3 volts. The performance investigation has been carried out using Finite Difference Time Domain (FDTD). Moreover the proposed design has a small footprint (420 μm2), guaranteeing its utility in low- power electrically tunable on-chip delay lines.