High-speed demodulation method and device for high-capacity weak grating sensing network

Abstract

The invention discloses a high-speed demodulation method for a high-capacity weak grating sensing network. The method comprises the following steps: (1) inscribing a plurality of weak gratings FBGr, FBG1, FBG2, FBG3 and the like in sequence on an optical fiber, wherein the FBGr is taken as a reference grating, and the FBG1, FBG2, FBG3 and the like are divided into m (m is more than or equal to 1) groups of identical weak grating arrays for constructing a sensing network; (2) generating pulse light by using a pulse laser, introducing the pulse light into the reference grating and the sensing network through an optical circulator, returning the reflected signal of each weak grating to the optical circulator, and introducing the reflected signals into an erbium-doped optical fiber amplifier for amplifying; (3) feeding the amplified reflected signals into a dispersion compensation optical fiber, receiving the time of the reflected signal of each weak grating by using a photoelectric detector, and performing signal processing through a high-speed data acquisition system to obtain the wavelength change of each weak grating in the sensing network in order to realize demodulation. A high-speed demodulation device for the high-capacity weak grating sensing network mainly comprises a pulse laser, an optical circulator, an optical fiber inscribed with a plurality of weak grating, am erbium-doped optical fiber amplifier, a dispersion compensation optical fiber, a photoelectric detector and a high-speed data acquisition system.

Description

technical field [0001] The invention belongs to the field of optical fiber grating sensing, and specifically refers to a high-speed demodulation method and device for a large-capacity weak grating sensor network, which is suitable for a large-capacity weak grating sensor network for multi-point and multi-parameter measurement. Background technique [0002] Optical fiber sensing technology is one of the fastest-growing high-tech application technologies in the world in recent years. Optical fiber sensing uses optical fiber to sense and obtain information and transmit the sensed information, in which optical fiber is used as both a sensing unit and a transmission medium. Optical fiber sensing has the advantages of anti-electromagnetic interference, long-distance transmission, easy networking, high sensitivity, and high reliability. These advantages are unmatched by other sensing technologies, especially for sensing applications under harsh environmental conditions. , Optical f...

AI Technical Summary

Problems solved by technology

At present, some optical fiber sensing networks can realize the measurement of thousands of points, but they can only realize the sensing of slowly changing parameters such as temperature and strain, and cannot realize the sensing of more parameters; while some optical fiber sensing networks can meet the requirements of multi-parameter measurement requirements, but the number of measurement points is limited

The sensor network constructed by time-division multiplexing technology and large-capacity weak grating can realize multi-point and multi-parameter measurement at the same time. However, the existing sensor network demodulation method has a long response time and is difficult to measure dynamically changing signals.

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