▎ 摘　　要

We report a simple, rapid, and nondestructive approach for precise determination of the number of graphene layers by placing the graphene on top of an all dielectric metasurface. The all dielectric metasurface is constituted with a periodic lattice of a rectangular silicon bar and a silicon ring. Due to the destructive interference between the radiation losses from bar and ring resonators, Fano resonance with high quality (Q) factor has been achieved from the metasurface, and thus the strong light-graphene interaction on top of the structure is allowed. By placing single layer, bi-layer, and few layers graphene above the metasurface, we find that both the amplitude and wavelength of Fano resonance can be dramatically changed. And such changes are large enough to be detected by a Fourier transform infrared spectrometer (FTIR). As a result, the thickness of graphene can be simply determined by monitoring the Fano resonance and the corresponding figure-of-merit(FOM) is as large as 6.5.