Vertical Comb-Drive MEMS Mirror for Optical Spectrum Sensing

We have proposed a vertical comb-drive MEMS mirror which can be applied for a spectrometer with phase-shifting method, and fabricated the mirror device using micro fabrication technology. The configuration of the MEMS mirror was designed with three vertical electrostatic comb-drive actuators and hinges at the periphery of the mirror. In the proposed spectrometer, the phase of the light which is reflected at the movable mirror is changed, and obtain the interferogram is obtained by the movable mirror which is driven precisely. We evaluated the moving characteristics of the fabricated MEMS mirror and confirmed that the MEMS mirror could be driven vertically to about 30 mum and also could be tilted. Using this MEMS mirror, we configured the spectrometer with a source of monochromatic light (lambda = 405 nm), and evaluated the spectroscopic characteristic in principle. Therefore, we have confirmed that the fabricated MEMS mirror can be applied to the spectrometer with phase-shifting method.