Micro-grating tilt sensor with self-calibration and direct intensitymodulation

A micro-grating tilt sensor based on phase diffraction grating with self-calibration capability and directintensity modulation is proposed. The optical tilt sensor consists of a coherent light source, gold grat-ings patterned on the transparent substrate, a silicon proof mass supported by the eight symmetricalAl cantilevers. Al membrane is sputtered on the bottom of the proof mass. Both Au and Al mem-brane serve as electrodes for electrostatic actuation. This can provide the sensitivity adjustment andself-calibration capabilities. Experiments show that the inclinometer provides the maximum incline sen-sitivity of 90 mV/°, resolution of 0.00006°, a measurement range of ± 5°in the rotational plane that isparallel to the direction of the gravity, and good self-calibration ability with electrostatic actuation.