Brillouin spectrum signal quality improving method

Abstract

The invention provides a Brillouin spectrum signal quality improving method. According to the method, reference Brillouin spectrum data are generated according to test parameters, the cross-correlation algorithm is used for accurately recognizing Brillouin signals from test Brillouin spectrum data with a lower signal-to-noise ratio through the reference Brillouin spectrum data, thus, the Brillouin spectrum signal recognizing capacity and the strain computational accuracy can be improved, and application of BOTDR products in long-distance optical fibers and severe construction environments can be greatly improved. By the adoption of the scheme, the signal-to-noise ratio requirement for the Brillouin signals is greatly reduced; the testing distance is increased; the stability of strain test results is improved; hardware modification is not needed, and therefore the improvement cost is low.

Description

Technical field [0001] The invention belongs to the technical field of Brillouin spectrum signal quality, and in particular relates to a method for improving the quality of Brillouin spectrum signal. Background technique [0002] The Brillouin Optical Time Domain Reflectometer (BOTDR) calculates the strain distribution of the fiber by measuring the Brillouin frequency shift distribution of the backward Brillouin scattered light in the fiber. The pulsed light is incident from one end of the fiber at a certain frequency, and the incident pulsed light After interacting with the phonons in the fiber, Brillouin scattering occurs, and the backward Brillouin scattered light returns to the incident end along the original path of the fiber. Because there is a linear relationship between the frequency shift of Brillouin scattered light in the optical fiber and the axial strain and temperature of the optical fiber, the strain distribution in the optical fiber can be calculated by measuring ...

AI Technical Summary

Problems solved by technology

[0003] Traditional BOTDR products directly fit and calculate the Brillouin spectrum data to obtain strain distribution data, but in the case of long fiber distances and weak Brillouin signals, the signal-to-noise ratio of the Brillouin spectrum data obtained is very low , the traditional direct fitting algorithm cannot accurately identify the Brillouin spectrum signal from the noise, resulting in a large error in the strain distribution results obtained by direct fitting, which cannot be used, which greatly affects the performance of BOTDR products in long-distance optical fibers and harsh construction environments. application

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