Photoelectronic device for distributed optical fiber temperature sensor

Abstract

The invention relates to a photoelectronic device for a distributed optical fiber temperature sensor, which belongs to the technical field of optical fiber sensing. The device comprises a first collimator tail optical fiber and a second collimator tail optical fiber. Wavelength division multiplexing filters are arranged on transmission light paths of a first collimator and a second collimator respectively. Band pass filters are arranged on light paths of the two wavelength division multiplexing filters respectively. A first self-focusing lens and a second self-focusing lens are arranged on the transmission light paths of the two band pass filters. A first avalanche photodiode, a second avalanche photodiode and temperature probes are arranged at the focuses of the two self-focusing lenses respectively. The distributed optical fiber temperature sensor utilizing the photoelectronic device can conveniently acquire accurate temperature information, and improves the temperature resolution of a system.

Description

technical field [0001] The invention relates to a photoelectric device, in particular to a photoelectric device used for a distributed optical fiber temperature sensor, and belongs to the technical field of optical fiber sensing. Background technique [0002] Since J.P.Dakin and others first successfully realized the distributed temperature measurement technology based on Raman scattering in 1985, people have carried out extensive research on various technologies for realizing distributed optical fiber temperature sensing. Sensing technology has been the most widely used in practice. Compared with traditional sensors, distributed optical fiber temperature sensors have many excellent advantages: using optical fiber itself as the sensing medium, temperature information of thousands of points distributed along the optical fiber can be obtained in one measurement, which realizes continuous distributed measurement and reduces the Measurement uncertainty; long measurement distanc...

AI Technical Summary

Problems solved by technology

First of all, this wavelength division multiplexing device uses a 1X3 bidirectional coupler, which will introduce an additional loss of about 9.5dB (10log(1 / 9)=9.5dB), which greatly weakens the available anti-Stokes light and Stokes light intensity; Secondly, the isolation of the device is difficult to exceed 40dB, the reason is the same as above

[0007] If the above-mentioned conventional wavelength division multiplexing device is used in a distributed optical fiber temperature sensor, due to insufficient isolation, it will cause mutual crosstalk between anti-Stokes light and Stokes light, and interference of Rayleigh scattered light. It is difficult to obtain accurate temperature information and high resolution. In severe cases, the temperature curve may even be distorted and the system may not work properly.

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