Multiwavelength Brillouin Optical Time Domain Analyzer

Abstract

The invention discloses a multi-wavelength Brillouin optical time domain analyzer which comprises a multi-wavelength laser device, a coupler, a probe pulse optical path, a continuous pump light path, a detector and a signal acquisition processor, wherein the probe pulse optical path comprises a probe pulse light modulation unit, a first erbium-doped optical fiber amplifier and a first circulator, and the continuous pump light path comprises a continuous pump light modulation unit, a second erbium-doped optical fiber amplifier, a second circulator, a Bragg grating and a polarization scrambler. The multi-wavelength laser device emits continuous light, and the continuous light is respectively input to the probe pulse optical path and the continuous pump light path through the coupler. By means of increase of the number of the wavelength of probe light and pump light, the multi-wavelength Brillouin optical time domain analyzer can increase the total luminous power of the entered optic fiber in the premise that stimulated Brillouin scattering is not caused and effectively improve the signal to noise ratio of a system. Meanwhile, the measuring efficiency is enabled to be improved, the measuring time is shortened for a certain sensing distance, and the sensing range is improved for a certain measuring time.

Description

technical field [0001] The invention relates to a Brillouin optical time domain analyzer based on a multi-wavelength light source, which is used for the Brillouin optical time domain analyzer in the fields of optical fiber sensing and optical cable health monitoring. Background technique [0002] The fully distributed optical fiber sensing technology uses the entire optical fiber as the sensing element, and utilizes the scattering phenomenon in the optical fiber to realize the continuous distribution measurement of the physical quantity to be measured (strain, temperature, etc.) on the sensing optical fiber as a function of time and space. BOTDA (Brillouin optical time-domain analysis, Brillouin optical time-domain analysis instrument) is a distributed optical fiber sensing system based on the stimulated Brillouin amplification effect, because the Brillouin optical time-domain analysis instrument has a sensing distance Long, high sensitivity, high measurement accuracy and ot...

AI Technical Summary

Problems solved by technology

However, due to the limitation of nonlinear effects in the optical fiber, the optical power incident on the optical fiber under test should be lower than the stimulated Brillouin threshold; in addition, increasing the number of averages will not only increase the measurement time, but also after the number of averages exceeds a certain number, Even if it is increased again, it will not significantly help the improvement of the signal-to-noise ratio

Therefore, the improvement of the system signal-to-noise ratio will be restricted in the above two aspects

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