A compact spectrometer based on a micromachined torsional mirror device

Abstract

We describe a spectrometer employing a microelectromechanical system (MEMS). A torsional micromirror device, which was originally designed for laser scanner applications, has been modified to act as a diffraction grating in a Czerny-Turner setup. This spectrometer system combines the working principle of a scanning monochromator with the compactness of a microsystem. The micromirror device is operated in a harmonic scanning mode at a resonant frequency of 500 Hz, enabling the system to acquire a spectrum per half cycle in one millisecond. The spectra of a calibration source in the visible and near-infrared spectral range as well as simulations concerning the optical system demonstrate the performance of the spectrometer.