FBG-based diaphragm type high-definition F-P optical fiber sound pressure sensor

Abstract

The invention provides an FBG-based diaphragm type high-definition F-P optical fiber sound pressure sensor, which belongs to the technical field of optical fiber sensors. Defects of a conventional F-P optical fiber sound pressure sensor are solved. The sensor comprises FBG written within an optical fiber, the optical fiber, a collimator lens which faces the end face of the optical fiber, a pigtailed sleeve, a casing which fixes the collimator lens and the pigtailed sleeve, and a sensitive diaphragm which is arranged on the end face of the casing. FBG and the sensitive diaphragm form a pair of reflector of an F-P cavity. From FBG to an outgoing end face and the collimator lens and from the collimator lens to an air cavity of the sensitive diaphragm form the F-P cavity length. Through the sensitive diaphragm, the optical fiber sensor has high sensitivity. An output signal of the sensor is demodulated through a phase demodulation method. The FBG-based diaphragm type high-definition F-P optical fiber acceleration sensor has a strong anti-jamming capability for temperature changes and laser wavelength drift.

Description

technical field [0001] The invention relates to an F-P pressure sensor, in particular to a FBG-based diaphragm type high-precision F-P optical fiber sound pressure sensor, which belongs to the technical field of optical fiber sensors. Background technique [0002] Optical fiber sensor technology is an emerging technology slowly formed with the development of optical fiber and optical fiber communication. It uses light as the carrier and optical fiber as the transmission medium to realize the sensing of the measured parameters. [0003] The traditional diaphragm type extrinsic F-P sensor is coated with a layer of high reflection film on the end of the optical fiber, which acts as a high reflection mirror, and the sensitive diaphragm acts as another reflection mirror. The two reflection mirrors form an F-P cavity, which can realize external signal interferometry. The cavity length of the traditional diaphragm extrinsic F-P sensor is relatively short, and the small processing...

AI Technical Summary

Problems solved by technology

The cavity length of the traditional diaphragm extrinsic F-P sensor is relatively short, and the small processing error of the interference cavity has a great influence on the demodulation result, so the processing repeatability of the cavity length of the interference cavity is difficult; when the ambient temperature changes, it will The slow change of the length of the interference cavity will cause the stability and accuracy of the demodulation results to deteriorate; interference factors such as wavelength drift will also affect the demodulation accuracy and stability of the traditional diaphragm extrinsic F-P sensor; the traditional membrane The chip extrinsic F-P sensor requires two mirrors to be parallel during assembly, so assembly is difficult

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