Anti-resonance optical fiber temperature detector

Abstract

The invention discloses an anti-resonance optical fiber temperature detector which comprises an anti-resonance optical fiber. One end of the anti-resonance optical fiber is connected with a beam expanding optical fiber, and the other end of the anti-resonance optical fiber is connected with a coupling optical fiber; one end of the beam expanding optical fiber is connected with the anti-resonance optical fiber, and the other end is connected with an uplink transmission optical fiber; one end of the uplink transmission optical fiber is connected with the beam expanding optical fiber, and the other end of the uplink transmission optical fiber is connected with an optical fiber light source; one end of the coupling optical fiber is connected with the anti-resonance optical fiber, and the otherend is connected with a downlink transmission optical fiber; and one end of the downlink transmission optical fiber is connected with the coupling optical fiber, and the other end is connected with an optical fiber spectrometer. Due to a fact that a silicon dioxide material is sensitive to a temperature, the temperature influences an optical path difference of the coherent light beams, and interference fringes read out by the optical fiber spectrometer change along with the temperature change of the anti-resonance optical fiber. By monitoring the movement of the fringes, the high-precision temperature monitoring of the anti-resonance optical fiber can be realized. Benefited from optimized device parameters and relatively high interference series, an anti-resonance optical fiber temperature detector has relatively high temperature detection sensitivity.

Description

technical field [0001] The invention relates to the technical field of photodetection devices, in particular to an anti-resonance optical fiber temperature detector. Background technique [0002] Currently commercial fiber optic temperature detectors include distributed fiber optic temperature sensors, interferometric fiber optic temperature sensors, and fiber optic Bragg grating temperature sensors. The distributed optical fiber temperature sensor uses OTDR technology to detect Raman scattered light and realize continuous and real-time temperature measurement in a large spatial range. Due to the weak Raman reflected light signal, it usually takes a long response time, and it is difficult to detect the precise position of temperature change, and the temperature detection accuracy is low; interferometric fiber optic temperature sensors include MZI type and F-P type temperature sensors. Although the sensing accuracy is high, the structure of the sensing element is complex. Th...

AI Technical Summary

Problems solved by technology

Because the Raman reflection light signal is weak, it usually takes a long response time, and it is difficult to detect the precise position of the temperature change, and the temperature detection accuracy is low; interferometric fiber optic temperature sensors include MZI type and F-P type temperature sensors

Although the sensing accuracy is high, the structure of the sensing element is complex. The MZI type temperature sensor needs two sections of optical fiber as the reference arm and the measuring arm. The F-P type temperature sensor measures the temperature by detecting the reflected light of the end surface coating. The layer is easily polluted by the external environment; the fiber Bragg grating temperature sensor causes the Bragg wavelength drift through the influence of temperature on the grating period and the refractive index of the material, thereby realizing temperature measurement

However, due to the influence of the material parameters of the fiber grating itself, the temperature measurement accuracy is low, and the measurement position accuracy is still limited due to the long measurement element.

[0003] Most of the above-mentioned detectors have large detection elements and a long working distance. Although the detection range is large, it will also lead to the lack of precise detection capabilities for single points, and cannot monitor local temperature changes.

At the same time, the detection sensitivity is limited by the detection principle and the material parameters of the fiber grating itself, which makes it difficult to meet the needs of high-precision temperature detection

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