Cladding reflection tilted fiber grating refractive index sensor, making method and measuring method

Abstract

The invention discloses a cladding reflection tilted fiber grating refractive index sensor, a making method and a measuring method. The sensor includes a light source, a sensing probe and a spectral demodulation device; the light source and the spectral demodulation device are separately connected to the sensing probe through an optical fiber circulator; the sensing probe includes single mode fiber having a cladding reflector and tilt fiber grating; the tilt fiber grating is connected to the single mode fiber, and has a cladding mode transmitting backward; and the cladding mode of the tilt fiber grating changes accordingly when the external refractive index of the tilt fiber gratin changes, and the changes of the external refractive index can be perceived by monitoring the changes of the light field wavelength and intensity of the cladding mode, so that the measurement on the refractive index can be realized. All-fiber high sensitivity refractive index measurement can be realized; andthe sensor is small in volume, light in weight, high in sensitivity, strong in anti-electromagnetic interference and stability and suitable for whole course monitoring.

Description

technical field [0001] The invention relates to a refractive index sensor, in particular to a cladding reflective inclined fiber grating refractive index sensor and a manufacturing and measuring method, belonging to the field of sensing technology. Background technique [0002] As we all know, compared with traditional electrical sensors, fiber grating sensors have the advantages of low loss, small size, light weight, anti-electromagnetic interference, chemical stability and electrical insulation. However, traditional fiber Bragg gratings are not sensitive to the ambient refractive index, and sensing applications based on refractive index changes cannot be realized. Long-period fiber gratings are sensitive to ambient temperature, strain and cross-refractive index, and their poor stability limits the application and popularization of long-period fiber gratings in actual measurement. [0003] Due to the introduction of the tilt angle of the grating, the tilted fiber grating e...

AI Technical Summary

Problems solved by technology

However, traditional fiber Bragg gratings are not sensitive to the refractive index of the environment, and cannot realize sensing applications based on changes in the refractive index.

Long-period fiber gratings are sensitive to ambient temperature, strain and refractive index crossover, and their poor stability limits the application and promotion of long-period fiber gratings in actual measurements

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