Novel Fabry-Perot interference MEMS (Micro Electro Mechanical System) sound wave sensor

Abstract

The invention discloses a novel Fabry-Perot interference MEMS (Micro Electro Mechanical System) sound wave sensor, which comprises a collimator, an SOI (Silicon on Insulator) wafer and a bushing, wherein the bushing is arranged below the SOI wafer and is used for supporting the SOI wafer and fixing the collimator; the SOI wafer is provided with a sound-sensitive film; the central axis of the bushing is coincided with the central normal of a circular silicon film on the SOI wafer; the end face of the optical fiber collimator inserted into the bushing is 100-300 microns away from the sound-sensitive film. According to the novel Fabry-Perot interference MEMS sound wave sensor, the end face of the optical fiber collimator provided with a tail fiber and the inner surface of a silicon micro film construct two parallel surfaces of a Fabry-Perot interferometer, and the film is deformed when pressure generated by external sound waves is applied to the film, so that the cavity length of an Fabry-Perot interference cavity is changed. The detection of sound wave signals is realized by modulating the length variation of the F-P cavity, so that a micro microphone with high interference resistance and high sensitivity is provided for use in an environment with strong electromagnetic interference.

Description

technical field [0001] The invention belongs to the technical field of microphones, in particular to a novel Fabry-Pérot interference type MEMS acoustic wave sensor. Background technique [0002] The sound wave is the propagation of the vibration of the object in the medium, and the sound wave sensor is a device that converts the sound signal in the medium into other detectable physical quantities, and restores the sound signal through these physical quantities. In recent years, acoustic wave sensors have been widely used in various fields, from medical equipment based on ultrasound diagnosis for civilian use to the detection of submarine targets in military applications. With the continuous exploration of acoustic signals, the role of acoustic detectors in the civilian and military fields will become more important in the future. [0003] At present, there are mainly several technical systems for acoustic wave sensors made by MEMS technology. 1. MEMS piezoelectric aco...

AI Technical Summary

Problems solved by technology

MEMS piezoelectric sensors have low sensitivity and poor anti-electromagnetic interference due to the limitation of materials; capacitive microphones generally use capacitive detection devices with acoustic cavities, including elastic vibrating membranes, detection capacitors and other devices with complex structures, so the structure is relatively Complex, which not only makes the processing more difficult, but also has the disadvantage of poor anti-electromagnetic interference ability

The power noise of the light source in the structure of the reflective fiber optic microphone greatly affects the reflected light intensity. In addition, the deformation of the uniform thickness reflective film causes the curvature of the thin plate to change, so that the coupling efficiency of the optical power reflected into the optical fiber is unstable, which also brings Instability of output optical signal

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