High-spatial-resolution temperature and strain optical fiber sensing system and measuring method

Abstract

The invention discloses a high-spatial-resolution temperature strain optical fiber sensing system and a measuring method, and belongs to the technical field of distributed optical fiber sensing. The problem of temperature and strain cross sensitivity in a distributed optical fiber sensing process is solved; the temperature and the strain are measured at the same time through Brillouin scattering and Rayleigh back scattering on the single-mode optical fiber, the Brillouin optical frequency domain analysis principle and the Rayleigh optical frequency domain reflection principle are combined, Brillouin frequency shift and back Rayleigh scattering wavelength shift are measured at the same time, and finally the temperature and the strain are measured on the basis of the difference of the sensitivity coefficients of the two physical quantities to the temperature and the strain. According to the optical fiber temperature and strain sensor, an optical frequency domain measurement method is adopted, and high-spatial-resolution temperature and strain simultaneous sensing can be achieved based on a single optical fiber.

Description

technical field [0001] The invention relates to an optical fiber sensing system, and belongs to the technical field of distributed optical fiber sensing. More specifically, the invention relates to a high spatial resolution temperature and strain optical fiber sensing system and a measurement method. Background technique [0002] When light is transmitted in an optical fiber, changes in physical fields such as temperature, strain, or electromagnetic field in the external environment will change parameters such as light intensity, wavelength, phase, frequency, and polarization state of the transmitted light. By monitoring the parameter changes of the transmitted light, the changes of the physical field parameters can be demodulated, that is, the sensing of physical quantities can be realized by using optical fibers. Compared with traditional sensing technology, optical fiber sensing technology has the advantages of high sensitivity, light weight, strong anti-electromagnetic i...

AI Technical Summary

Problems solved by technology

However, most sensing systems relying on a single optical parameter are difficult to achieve common sensing of temperature and strain, and some even have cross-sensitivity problems, which will introduce errors in actual monitoring, resulting in indistinguishable changes in temperature and strain

With the application of special optical fibers and the development of sensing technologies based on other scattering mechanisms, the problem of temperature-strain cross-sensitivity has been solved to some extent, but it is difficult to ensure high spatial resolution. Structural deformation monitoring and other occasions that require short distance and high spatial resolution have application bottlenecks, and a high spatial resolution temperature and strain simultaneous sensing solution is urgently needed

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