A method and device for automatically measuring the temperature coefficient of optical quantum botdr optical fiber

Abstract

The invention provides a method and device for automatically measuring the temperature coefficient of an optical quantum BOTDR optical fiber. The device includes: a direct detection optical fiber temperature distribution tester connected in sequence, a constant temperature box and a computer; a number of test optical paths for placing sample optical fibers are arranged in the said constant temperature box, and the ambient temperature of the sample optical fiber is simulated; the direct The detection type optical fiber temperature distribution tester is used for the distribution measurement of the back elastic scattering light quantum power of the sample fiber and the Brillouin-Stokes component light quantum power; the computer is based on the sample fiber back elastic scattering light quantum power distribution data and The power distribution data of the Brillouin-Stokes component light quantum in the backward direction of the sample fiber is used to obtain the power ratio, and the temperature calibration coefficient of the sample fiber for all channels is obtained based on the power ratio.

Description

technical field [0001] The invention belongs to the field of optical fiber temperature measurement, and in particular relates to a method and device for automatically measuring the temperature coefficient of an optical quantum BOTDR optical fiber. Background technique [0002] The statements in this section merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] Direct detection optical fiber temperature distribution tester (also known as photon Brillouin optical time domain reflectometer, referred to as PB-OTDR) due to its continuous distribution, long test distance, high measurement accuracy, corrosion resistance, intrinsic safety, anti-electromagnetic interference, It does not require frequency scanning and can form a sensor network. It has been widely used in the fields of power cable temperature monitoring, intelligent pipeline temperature monitoring, oil transportation and storage facilities temperatu...

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Problems solved by technology

However, the system structure of the heterodyne detection method is relatively complicated, and the Brillouin gain spectrum is usually obtained by scanning the spectrum point by point, thereby reducing the time resolution of the measurement, which usually takes tens of seconds to several minutes

Obviously, the optical fiber temperature distribution tester (Brillouin optical time domain reflectometer, referred to as BOTDR) working in frequency sweep mode as a test device needs to repeatedly construct the Brillouin gain spectrum to calculate the temperature coefficient of the sample fiber, and for different For sample fibers with different batches, different processes and different particle doping ratios, due to the large frequency span of the Brillouin gain spectrum, the number of Brillouin gain peaks contained in the Brillouin gain spectrum, and the difference between multiple acoustic wave fields Factors such as the diversification of the Brillouin gain spectrum pattern caused by the mutual coupling between the samples make the calibration process of the temperature coefficient of the sample fiber complex, time-consuming, large in error and not universal

[0005] At present, the calibration of the temperature coefficient of the sample fiber in different batches, different processes and different particle doping ratios in the PB-OTDR system mainly depends on manual calibration. Analyze the Brillouins astigmatism power distribution trace to realize the calibration of the temperature length of the sample fiber. Due to many subjective factors in manual analysis, it will affect the accuracy of coefficient calibration; and manual temperature coefficient calibration is very inefficient and difficult to meet Demands during the production and use of PB-OTDR; at the same time, manual calibration of the stability coefficient also leads to increased labor costs

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