Distributed Brillouin optical fiber bending sensor with enhanced sensitivity

Abstract

The invention discloses a distributed Brillouin optical fiber bending sensor with enhanced sensitivity. The sensor comprises a coupler, a first polarization controller, a second polarization controller, a first Mach-Zehnder modulator, a second Mach-Zehnder modulator, a waveform generator, a scrambler, a first wavelength division multiplexer, a first pump light source, an erbium-doped optical fiber amplifier, a few-mode erbium-doped optical fiber, a second wavelength division multiplexer, a first optical fiber circulator, an isolator, a second pump light source, a second optical fiber circulator, an optical fiber Bragg grating filter, a photoelectric detector and an oscilloscope. The erbium-doped ring core few-mode optical fiber is pumped by using a high-power light source, so that the erbium-doped ring core few-mode optical fiber generates a spontaneous radiation spectrum, and signal light transmitted in the optical fiber is amplified, so that loss generated by bending of the optical fiber is made up, a larger bending radius detection range is realized, and the bending radius detection sensitivity is enhanced.

Description

technical field [0001] The invention belongs to the field of optical technology, in particular to a distributed Brillouin optical fiber bending sensor with enhanced sensitivity. Background technique [0002] In the past decades, fiber optic sensors have been extensively studied due to their advantages such as compact structure, low cost, long sensing range, corrosion resistance, and immunity to electromagnetic interference. Distributed optical fiber sensors can realize continuous multi-point measurement on one optical fiber, and have the advantages of long measurement distance and simple wiring. Brillouin optical time-domain analysis technology is a kind of distributed optical fiber sensing technology. It can measure the change of absolute physical quantity. It has the advantages of long measurement distance, high spatial resolution, high measurement accuracy and high signal-to-noise ratio. It has important application value in fields such as oil pipeline, subway urban rail...

AI Technical Summary

Problems solved by technology

This method can exclude temperature cross-sensitivity, but the bending loss of single-mode fiber is large, resulting in a small measurable radius and poor flexibility

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