Brillouin intensity and frequency shift strain temperature coefficient automatic testing system and method

Abstract

The invention discloses a Brillouin intensity and frequency shift strain temperature coefficient automatic test system and method, and belongs to the technical field of photoelectric measurement and optical fiber sensing. The invention provides a 1310nm and 1550nm dual-band Brillouin scattering intensity and frequency shift strain temperature coefficient automatic test method, and designs a portable and telescopic optical fiber strain temperature coefficient test platform capable of adapting to different optical fiber strain action area requirements. Automatic testing of a Brillouin scatteringintensity strain coefficient, an intensity temperature coefficient, a frequency shift strain coefficient and a frequency shift temperature coefficient of 1310 nm and 1550 nm wavelengths is achieved,the testing efficiency of the optical fiber strain temperature coefficient is improved, the coefficient analysis precision is improved, technical guarantee is provided for the Brillouin scattering signal intensity and frequency dual-demodulation decoupling type optical fiber strain distribution tester, and the application range of an optical fiber strain distribution tester is further expanded.

Description

technical field [0001] The invention belongs to the technical field of photoelectric measurement and optical fiber sensing, and in particular relates to an automatic testing system and method for Brillouin intensity and frequency shift strain temperature coefficient. Background technique [0002] The Brillouin Optical Time Domain Reflectometer (BOTDR for short) relies on measuring the Brillouin backscattered light distribution information of the optical fiber to calculate the strain distribution of the optical fiber. Brillouin optical time domain reflectometer can be used in geotechnical engineering health monitoring, geological disaster early warning monitoring, cable and pipeline health monitoring and other fields. It is one of the most powerful products used to replace traditional point sensors in the engineering field. However, during the use of BOTDR, its strain distribution and temperature distribution are obtained by analyzing and demodulating the spontaneous Publishe...

AI Technical Summary

Problems solved by technology

However, during the use of BOTDR, its strain distribution and temperature distribution are obtained by analyzing and demodulating the spontaneous Publisher scattering. In the analysis process, it is necessary to rely on the optical fiber strain coefficient and temperature coefficient to obtain accurate strain distribution. Or the temperature distribution value, the traditional gauge coefficient (hereinafter referred to as the frequency shift gauge coefficient) and the temperature coefficient (hereinafter referred to as the frequency shift temperature coefficient) are calculated using the Brillouin scattering frequency shift value, currently there are technologies using the Brillouin The double demodulation of the intensity and frequency of the Brillouin scattering signal realizes the decoupling of the optical fiber strain distribution data and the temperature distribution data. The traditional frequency shift strain coefficient and frequency shift temperature coefficient obtained based on the Brillouin scattering spectrum frequency shift analysis are difficult to meet this test. According to the analysis requirements, this method also needs the intensity gauge coefficient and intensity temperature coefficient based on the Brillouin scattering signal intensity analysis. At the same time, there are new methods that require the intensity gauge coefficient and intensity temperature coefficient of 1310nm

[0003] At present, the test schemes for the strength gauge coefficient and strength temperature coefficient are all manually built and tested manually. The gauge coefficient test process is at room temperature, and it is difficult to keep the indoor temperature constant, which has a certain impact on the temperature coefficient test. And the test The efficiency is very low, it is difficult to promote, and at the same time, it is impossible to test in the field environment such as the engineering site, which restricts the application and promotion of optical fiber strain distribution technology

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