Electrically tunable nanophotonic switch based on graphene-silicon hybrid ring resonator

A nanophotonic switch based on electrically tunable graphene-silicon ring resonator is realized by tuning the resonant wavelengths of ring resonator. The shift in resonant wavelengths of the ring is achieved through modulation of fermi energy level of graphene by means of electrical gating. The hybrid plasmonic structure of the ring confines the light in nanoscale dimensions. The gap and length of the ring are optimized for better extinction ratio. The proposed optical switch exhibits an extinction ratio of 10.94 dB at a wavelength of 1550 nm. A minimum gap of 100 nm and a smaller ring radius of 3.1 mu m offer minimal footprint area. The real and imaginary parts of the effective index of the ring w.r.t voltage across the graphene are observed. The reported results open the way for more optical switches, modulators based on electrically controllable characteristics of the graphene and the ring resonator. The proposed design finds applications in optical interconnects, optical static random-access memory (SRAM's) and other integrated photonic devices.