19 September 2013 Wavelength stabilization of electrostatically actuated micromechanical infrared Fabry-Pérot filters
Author Affiliations +
In this work, an application of electrostatically tunable optical infrared filters in a closed-loop control system is presented. The filters are based on a Fabry-Pérot architecture, fabricated in a bulk micromachining process. Compared to surface micromachined devices, this design opens a path to higher optical performance due to the high planarity and low roughness of substrates but also introduces the drawback of acceleration sensitivity because of a moving mass. To overcome this problem, the filter is driven by a closed-loop control system, with feedback from a charge amplifier that measures the capacitance of the control electrodes. A PI-based controller that adapts to nonlinear stiffness and damping by real-time calculation of the deflection dependent controller parameters is developed. Basic system parameters are derived from optical calibration measurements and step-response results. At 5 Hz sinusoidal accelerations of 1 g, the filter wavelength accuracy can be improved from ±35 nm in open-loop case down to ±2 nm in closed-loop operation.
© (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jörg R. Schröter, Sebastian Lehmann, Martin Ebermann, and Norbert Neumann "Wavelength stabilization of electrostatically actuated micromechanical infrared Fabry-Pérot filters", Proc. SPIE 8868, Infrared Sensors, Devices, and Applications III, 88680J (19 September 2013); doi: 10.1117/12.2024822; https://doi.org/10.1117/12.2024822

Back to Top