Figure 5.

The operation of the SPR sensor based on SiO₂/Au (Au-thickness equals to 40 nm) chip with the metamaterial, consisting of alternating layers graphene and h-BN (a,b). (a) The dependence of the reflection coefficient as a function of the incident angle at the 800 nm wavelength and 10-nm-thick metamaterial. The black curve corresponds to the absence of the metamaterial layer; red, blue, and green curves calculated using different optical properties of graphene, that were reported. (b) The dependence of the sensitivity of this SPR sensor on the thickness of the metamaterial. (c) The TM-mode reflectance from the 20-nm-thick metamaterial, consisting of alternating layers graphene and h-BN, placed on the SiO₂/Si substrate (SiO₂ thickness equals to 280 nm), as a function of the incident angle at 530 nm free-space wavelength. Red, purple and blue-green curves were calculated using optical properties of graphene from different sources. The optical constants of graphene of Ochoa-Martinez and Castriota are adopted for calculations from refs. [28,31], respectively.