f-p pressure sensor with composite dielectric film

Abstract

A F-P pressure sensor with a composite dielectric film disclosed by the present invention comprises an upper ferrule with a F-P resonant cavity, a lower ferrule which is axially fixedly connected with the upper ferrule and inserted into the lower ferrule. A ferrule for the fiber, and a pressure diaphragm covering the port of the F‑P resonator. At least one layer of composite dielectric film is grown on the back side of the pressure diaphragm and the silicon wafer at the bottom of the groove of the F-P resonator, and the composite dielectric film is SiO 2 / Ta 2 o 5 Thin film, Si 3 N 4 / Ta 2 o 5 thin film or SiO 2 / Ta 2 o 5 / Si 3 N 4 A multilayer film in at least one combination form. The invention has the advantages of simple structure, convenient and quick manufacture, low cost and high thermal stability. In the present invention, a composite dielectric film is grown on the back of the pressure diaphragm and the bottom surface of the upper ferrule groove, and the F-P resonant cavity is formed by connecting the pressure diaphragm with the upper ferrule to match the reflectivity of the system. This combined composite dielectric film is not only thermally stable At the same time, it can be combined according to the design requirements to obtain the reflectivity that meets the system requirements.

Description

technical field [0001] The invention relates to an optical fiber F-P sensor widely used in the measurement of physical quantities such as temperature, strain, vibration and pressure, in particular to an F-P pressure sensor with a composite dielectric film. Background technique [0002] Optical fiber sensors use light as the information carrier and optical fiber as the signal transmission medium to sense and measure the measured parameters. It has good electrical insulation, strong anti-electromagnetic interference ability, and also has high temperature, high pressure, corrosion resistance characteristics, and can be used in harsh environments such as flammable and explosive. Optical fiber Fabry-Fabry (F-P) sensor is an important branch of optical fiber sensor. The sensitive part of the fiber optic F-P resonator pressure sensor is the fiber F-P resonator. When the light enters the fiber F-P cavity, it will be reflected multiple times between the two reflective end faces to f...

AI Technical Summary

Problems solved by technology

[0009] The purpose of the present invention is to provide a F-P pressure sensor with good thermal stability, high precision and good reliability, and a composite dielectric film to solve the problems of the current optical fiber F-P pressure sensor. Stability and reflectivity bring accuracy loss issues

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