▎ 摘　　要

A reflection-type refractive-index sensor based on the surface plasmon resonance of graphene in the mid-infrared to terahertz regime is proposed. With a simple configuration, the sensor demonstrates high flexibilities for the gas and liquid samples sensing and achieves markedly improved figures of merit of 53.64 and 36.5 RIU-1, respectively. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)