Relative humidity sensor based on PCF air chamber and tilted fiber bragg grating

Abstract

The invention discloses a relative humidity sensor based on a PCF air chamber and tilted fiber bragg grating, which is composed of a broadband light source, a polarization controller, an optical fiber circulator, a single mode optical fiber, a PCF air chamber, the titled fiber bragg grating, a graphene oxide film, a first spectrograph and a second spectrograph; the front end of the tilted fiber bragg grating is connected with a previous section of PCF in a welding manner, HF acid is used to corrode an air hole in the PCF to form a hexagonal air chamber, of which the inner wall is smooth, in the interior of an optical fiber, and the graphene oxide film is uniformly plated on the surface of the titled fiber bragg grating to form the relative humidity sensor with a novel structure accordingly. A film refractive index is changed during the process of adsorption and release of water molecules by the graphene oxide film, and by combining the properties of highly sensitivity to refractive index change of the titled fiber bragg grating to the surface of the optical fiber, the relative humidity measurement is realized. The relative humidity sensor disclosed by the invention is compact in structure and high in sensitivity, can effectively solve the problem of the temperature cross-sensitivity during the humidity sensing process, and has certain actual application value.

Description

technical field [0001] The invention belongs to the technical field of optical fiber humidity sensing, in particular to a relative humidity sensor based on a PCF air cavity and an inclined optical fiber grating. Background technique [0002] At present, the humidity monitoring methods based on mechanical and electrochemical hygrometers cannot meet the actual needs of humidity sensing under the conditions of high temperature and high pressure, long-distance signal transmission, and strong electromagnetic interference in the nuclear industry and power transmission industry. The fiber optic humidity sensor gets rid of the framework of the traditional mechanical / electrical humidity sensor, innovatively uses optical fiber as the carrier, and completely replaces the complicated mechanical structure, which has attracted extensive attention and research in recent years. [0003] Photonic Crystal Fiber (PCF) can be divided into two types: index-guided type and photonic bandgap type a...

AI Technical Summary

Problems solved by technology

[0002] At present, the humidity monitoring methods based on mechanical and electrochemical hygrometers cannot meet the actual needs of humidity sensing under the conditions of high temperature and high pressure, long-distance signal transmission, and strong electromagnetic interference in the nuclear industry and power transmission industry.

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