▎ 摘 要
We found that the intensity of Raman scattering spatially oscillates over single- and double-layer graphene suspended over micro-fabricated silicon dioxide/silicon cavities. CVD-grown graphene sheets were transferred onto circular micro-cavities and intensities of G band and 2D band Raman peaks exhibited clear oscillation forming concentric circular patterns. We proposed the origin of oscillation as a multiple-beam interference and confirmed the model through theoretical calculations. The model well explains our experimental observations and can be applied to other laser-spectroscopy on 2D materials suspended over micro-cavities.