Micro-electro-mechanical systems resonant optical gyroscope

摘要

A gyroscope is based upon the integration of an optical resonant cavity and a photodiode to detect minute perturbations due to angular forces. A Fabry-Perot cavity is created from two parallel semitransparent mirrors used in conjunction with a monochromatic light source. One mirror is fixed while the other is allowed to rotate with respect to the first mirror. A resonant cavity is thereby formed on either side of the axis. The gap between the mirrors is set so that light transmission through the mirrors is optimized. Rotation of the mirror from this position causes the distance between the mirrors to be altered and the light transmission on either side of the rotational axis to be change. Photodiodes on these sides sense this change as a change in photo-generated current, enabling the amount of change in rotation to be calculated. The photo-currents can be differentially amplified for sensitivity.