Design of MEMS-based micro-filter integrating grating and tunable Fabry-Perot cavity

This paper presents basic designs and operation concepts of a novel micro-electro-mechanical-systems (MEMS) filter integrating a tunable Fabry-Perot (FP) cavity and a grating. It is based on the filtering effect of the tunable FP cavity and the spatial separation function of the grating for the different wavelengths. The combination of two devices could widen the spectral range of the traditional FP filter without affecting its spectral linewidth. A MEMS filter configuration based on the silicon-glass bonded structure has been designed. The FP cavity length depends on the thickness of the silicon wafer itself to realise the long cavity length. The T-S cantilevers could decrease the micromirror deformation, and reduce the driving voltage appropriately. Calculational results indicate that narrow linewidth and wide spectral range could be obtained simultaneously at the long cavity length.