Vibration sensor utilizing a feedback stabilized fabry-perot filter

Abstract

A sensor and method for using the same is disclosed. The sensor includes an optical cavity defined by first and second mirrors that have a spacing therebetween that varies in response to a force applied to the sensor and to a control voltage. The sensor has a drive circuit that measures light leaving an output port that samples light in said cavity and applies the control voltage to the optical cavity such that the spacing between the mirrors remains at a predetermined value independent of the force, the control voltage determining an output signal that provides a measurement of the force applied to the optical cavity. In one embodiment, the first mirror is fixed to the second mirror by a spring mechanism that causes the first mirror to move away from the second mirror, and the control voltage causes the first mirror to move toward the second mirror.

Dependencies are inferred from the claim text.