Device and method for simultaneously measuring temperature and strain based on chaotic bocda

Abstract

The invention belongs to the field of distributed optical fiber sensing systems, and discloses a device for simultaneously measuring temperature and strain based on chaotic BOCDA, including a chaotic laser, a fiber coupler, a first polarization controller, a first electro-optical modulator, and an optical delay generator , first optical amplifier, optical scrambler, sensing fiber, second polarization controller, second optical amplifier, signal generator, second electro-optic modulator, third optical amplifier, optical circulator, filter, photodetector devices, lock-in amplifiers, arbitrary pulse function generators, data acquisition cards and computing units. The present invention utilizes the characteristic that the Brillouin gain spectrum measured in the LEAF optical fiber by the chaotic BOCDA system has multiple peaks, and the linear coefficients of the Brillouin frequency shift of each peak with temperature or strain are different, on the premise of ensuring high spatial resolution Under this condition, the simultaneous measurement of temperature and strain is realized.

Description

technical field [0001] The invention belongs to the field of distributed optical fiber sensing systems, and in particular relates to a device and method for simultaneously measuring temperature and strain based on chaotic BOCDA, which are used to realize simultaneous measurement of temperature and strain. Background technique [0002] Optical fiber sensing technology uses optical fiber as the signal sensing and transmission medium. Compared with traditional sensors, optical fiber has the advantages of small size, high sensitivity, and strong anti-electromagnetic interference ability. Therefore, fiber optic sensing technology has attracted people's attention once it appeared. , It has been widely used in national defense, military, aerospace, metrology and testing and other fields. [0003] The distributed optical fiber sensing system mainly includes three sensing systems based on the Rayleigh scattering effect, based on the Raman scattering effect and based on the Brillouin ...

AI Technical Summary

Problems solved by technology

However, the method of using chaotic Brillouin dynamic grating to measure temperature and strain at the same time has a complicated structure, and a device for generating Brillouin dynamic grating is required in the sensing system.

Moreover, the effective grating length of the Brillouin dynamic grating produced in the polarization-maintaining fiber is limited, and it is difficult to be popularized in practical applications

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