Broadband and compact two-mode switch using a graphene–silicon Y-junction

Abstract

A compact two-mode switch with broad bandwidth is presented in this paper. The design of the proposed switch is based on a symmetric Y-junction which is composed of a silicon multimode straight waveguide, a silicon taper, and two symmetrical graphene–silicon s-bend waveguides. When voltage signals are applied to efficiently change the chemical potential of the embedded graphene, input modes can be separated, converted, and routed to the output ports flexibly at a high speed. Calculations indicate that, the crosstalk of the presented switch with an area of ∼65×∼1.7μm2 is less than −12.10 dB over a 95 nm band, the switching voltage for shifting the chemical potential is 4.18 V, the corresponding energy consumption is less than 2.90 pJ/bit, and the calculated 3-dB bandwidth larger than 47.94 GHz can be obtained.