Micro-spectrometer using electrothermal tunable MEMS grating

Abstract

Miniaturized spectrometers are widely used for non-destructive and on-field spectral analysis. Here we report a tunable MEMS grating-based MEMS spectrometer for visible to near-infrared (VIS-NIR) spectroscopy. The micro-spectrometer consists of a spherical mirror and an electrothermally actuated tunable MEMS grating. The spectrometer detects the dispersed spectral signal with a single-pixel detector by tilting the diffraction grating. The large tilting angle from electrothermal actuation and highly dispersive diffraction grating improves the spectral range and resolution, respectively. The micro-spectrometer was fully packaged within 1.7 cm3 and provides a measurable spectral range up to 800 nm with an average 1.96 nm spectral resolution. This miniaturized single-pixel spectrometer can provide diverse applications for advanced mobile spectral analysis in agricultural, industrial, or medical fields.