Method of detecting sound using a micro-electro-mechanical system optical microphone

摘要

A micro-electro-mechanical system (MEMS) optical sensor, method of detecting sound using the MEMS optical sensor and method of manufacturing. The MEMS optical sensor including a substrate having a base portion and a vertically extending support portion. The sensor further including a top plate having a compliant membrane configured to vibrate in response to acoustic waves, the top plate connected to the support portion and having a reflective surface. The sensor also includes a back plate connected to the support portion, the back plate having a grating portion positioned below the reflective surface portion and a base plate connected to the support portion at a position below the back plate. A light emitter, a light detector and circuitry operable to tilt the top plate and the back plate with respect to the base plate so as to direct the reflected laser light toward the light detector are further provided.

主权项

1. A method of detecting sound using a micro-electro-mechanical system (MEMS) optical microphone, the method comprising:
providing the MEMS optical microphone having a compliant membrane with a reflective portion configured to vibrate in response to an acoustic wave, a back plate having a grating, a base plate, a light emitter, a light detector and circuitry; applying a voltage, using the circuitry, to tilt the compliant membrane and the back plate with respect to the base plate; illuminating the reflective portion of the compliant membrane with a light emitted from the light emitter; and detecting, using the light detector, a diffracted pattern of the light from the light emitter after reflection from the reflective portion to provide an indication of sound.