Wavelength stabilization of MEMS Fabry-Pérot filters by capacitive sensing — Approach and experimental results

Electrostatically actuated MEMS Fabry-Pérot filters are an innovative component for infrared microspectrometers and miniature gas sensors. Fabricated in a bulk micromachining process, difficulties can arise from the mass of moving elements making the device sensitive to acceleration forces. To counteract this problem the capacitance of the electrostatic actuator can be measured and used in a closed control loop circuit. This paper gives a short overview on how such a closed-loop control system was implemented and subsequently focuses on experiments for evaluating the command and disturbance response. To investigate the latter, the behavior of the whole system was measured in a vibration test system.