Graphene-layered refractive index sensor by metal-assisted guided mode resonance structure

In this paper, with the combination of metal assisted guided-mode resonance (MaGMR) and graphene, a graphene-layered MaGMR refractive index sensor is proposed. With the optimization by finite difference time domain method, the sensor can achieve perfect absorption at the near infrared band. The electric intensity distribution of the sensor is studied and shows descent resonance phenomena at the resonant wavelength. The investigation on the detection of analytes with different refractive indices around the sensor is conducted and it shows that the proposed sensor has superior sensing performance with a sensitivity of 590 nm/RIU and figure of merit 180.98 RIU⁻¹. The influence of the Fermi level of graphene on the tunability of the sensor is also analyzed. To measure the performance deviation when there is a manufacturing error, the structural parameters of the sensor are also investigated. The proposed sensor exhibits great sensing performance and therefore has many potential applications in sensing, environmental monitoring and detection fields.