Optical fiber temperature and pressure sensor for double-cavity structure and a preparation method thereof

Abstract

The invention provides an optical fiber temperature and pressure sensor for a double-cavity structure and a preparation method thereof. The sensor comprises an incoming component, which is provided with an incoming optical fiber for guiding the incidence of related light beams; a reflecting component, which comprises a reflecting optical fiber used for keeping a reasonable distance with the incoming component so as to form an intrinsic type F-P cavity and a non-intrinsic type F-P cavity. The intrinsic type F-P cavity is formed by welding a second capillary tube and a section of optical fiber;the non-intrinsic type F-P cavity is formed by keeping reasonable distance with the end surface of the incoming component or the reflecting component; a first capillary tube is fixedly connected withthe components. According to reflection of the cavity length of the non-intrinsic type F-P cavity to the related light beams, the measuring temperature and pressure can be obtained; according to the reflection of the cavity length of the intrinsic type F-P cavity to the related light beams, the measuring temperature can be obtained; accurate measurement pressure is obtained after temperature compensation. The invention is advantageous in that the temperature compensation is carried out on the non-intrinsic cavity through the intrinsic cavity, obtaining accurate pressure value; the structure issimple and manufacturing is easy.

Description

technical field [0001] The invention relates to an optical fiber temperature and pressure sensor, in particular to an optical fiber temperature and pressure sensor with a double-cavity structure and a preparation method thereof. Background technique [0002] Optical fiber Fabry-Perot sensor is an interference sensor formed by F-P cavity constructed by optical fiber and capillary, which can be divided into intrinsic type and extrinsic type. Among them, the intrinsic F-P sensor (Intrinsic Fabry-Perot Interferometer, IFPI) uses the optical fiber itself to form an F-P cavity with a cavity length of L, and the extrinsic F-P sensor (Extrinsic Fabry-Perot Interferometer, EFPI) uses two optical fiber end faces (two The air gap between the end faces coated or uncoated) constitutes an F-P cavity with a cavity length L. When the coherent light beam enters the F-P cavity along the fiber, the fiber returns along the original path after being reflected by the two ends of the F-P cavity a...

AI Technical Summary

Problems solved by technology

[0004] However, the above-mentioned solution of adding a fiber grating to measure temperature has higher requirements on the packaging of the sensor, especially the optical fiber in the grating part needs to be in a free state without stress

Although the combination of intrinsic and extrinsic F-P cavity can obtain temperature and pressure at the same time, the sensor structure is complex and difficult to manufacture

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