Self calibration for mirror positioning in optical MEMS interferometers

Abstract:

Microelectromechanical Systems (MEMS) devices provide self-calibration of mirror positioning of a movable mirror of an interferometer. At least one mirror in the MEMS device includes a non-planar surface. The moveable mirror is coupled to a MEMS actuator having a variable capacitance. The MEMS device includes a capacitive sensing circuit for determining a capacitance of the MEMS actuator at a plurality of reference positions of the movable mirror corresponding to a central burst and one or more secondary bursts of interferograms generated by the interferometer based on the non-flat surface. The calibration module uses the actuator capacitance at the reference position to compensate for any drift in the capacitive sensing circuit.