Linear absorption coefficient of graphene-silicon hybrid waveguide determined by in-plane symmetrical add-drop silicon microring resonator

In this paper, we propose a novel method to experimentally determine the linear absorption coefficient (LAC) of graphene-silicon hybrid waveguides (GSHWs) by a symmetrical add-drop silicon microring resonator. Experimental results show that the LAC of a GSHW has an average value of 0.23 dB/µm. Our approach does not depend on the fiber coupling, waveguide end facets etc. and thus, is promising for future high-performance graphene-silicon optoelectronic devices.