Fine core microstructure optical fiber interferometer sensor and temperature and strain detection method therefor

Abstract

The invention discloses a fine core microstructure optical fiber interferometer sensor and a temperature and strain detection method therefor. The fine core microstructure optical fiber interferometer sensor comprises a broadband light source, a sensing head and a spectrograph, wherein the sensing head is a fine core microstructure optical fiber having an air dome layer, and two ends of the fine core microstructure optical fiber are respectively connected with the broadband light source and the spectrograph via single mode optical fibers. Light emitted from the broadband light source enters the fine core microstructure optical fiber via the single mode optical fibers; because the single mode optical fibers and the fine core microstructure optical fiber are mismatched in mode field, the spectrograph outputs spectrums which include interference fringe spectrums, and temperature change or strain can cause wavelength shift of an interference fringe wave trough; when the wavelength shift of the interference fringe wave trough is known, temperature change or strain can be calculated correspondingly. Due to the air dome layer in the fine core microstructure optical fiber, a technical problem of refraction index cross sensitivity of external environment can be prevented; temperature and strain detection accuracy of the sensor is improved, and the sensor disclosed in the invention can be effectively applied to high humidity or liquid environment.

Description

technical field [0001] The invention relates to an interferometer sensor, in particular to a fine-core microstructure optical fiber interferometer sensor and a temperature detection method and a strain detection method thereof. Background technique [0002] The all-fiber interferometer mainly uses the interference fringes formed by the multiple reflections of light or the separation between modes to detect the characteristic parameters of the external environment. Its structure is simple, easy to install, and its cost is relatively low compared to other sensors. It can be used as a A preferred option. Temperature and strain are one of the most commonly detected physical quantities in physical quantities. It is of great significance to accurately measure, detect and control temperature and strain in the fields of industrial engineering, civil engineering, and military technology. [0003] However, the problem of refractive index cross-sensitivity is an unavoidable problem in...

AI Technical Summary

Problems solved by technology

The traditional fiber mode interferometer is based on the interference between the core mode and the cladding mode. The cladding mode is sensitive to the refractive index change around the fiber, so this type of sensor cannot be used in liquid or high humidity environment

In response to this problem, people have proposed a method of simultaneously measuring the surrounding refractive index and other parameters, but this method requires the use of matrix solutions, and the calculation is quite complicated

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