Demodulation system and method of fiber grating sensor based on edge filtering and time division multiplexing

Abstract

The invention discloses a demodulation system and method of a fiber grating sensor based on edge filtering and time division multiplexing. A plurality of fiber F-P lasers with different center wavelengths transmit laser signals of respective central wavelengths. The laser signals through a fiber into a circulator. The circulator injects a combined laser into a sensing unit. The sensing unit comprises a plurality of sets of sensing arrays connected in series. Each set of sensing arrays comprises a plurality of fiber gratings connected in series corresponding to different center wavelengths. Each of the sensing arrays is connected by a time division delay fiber. The circulator simultaneously receives the optical signal fed back by the sensing unit, and separates the different wavelengths ofthe incident light and transmits the same to a processing unit. The processing unit amplifies the optical signals of different wavelengths and performs edge filtering. The processing unit demodulatesthe fiber grating sensing arrays with the same wavelength type according to the signal return time. High frequency demodulation of a large-capacity fiber grating sensing array on a single fiber can beachieved by combining edge filtering and time division multiplexing.

Description

technical field [0001] The invention relates to an optical fiber grating sensing demodulation system and method based on edge filtering and time division multiplexing. Background technique [0002] Optical fiber sensing technology is a new type of sensing technology that uses light as the carrier and optical fiber as the medium to perceive and transmit external signals (measured) and has developed rapidly with the development of optical fiber and optical fiber communication technology. Fiber Bragg grating is one of the typical optical fiber sensing devices, and its central wavelength has a good linear relationship with temperature and stress applied to the grating. distributed sensing. At present, the development trend of fiber grating sensor technology is as follows: on the one hand, the sensor types of fiber grating sensing system are becoming more and more abundant, the sensing ability is greatly enhanced, and the system scale is continuously expanding; In the direction...

AI Technical Summary

Problems solved by technology

The single edge filter and tunable filter method have small sensor capacity, and the tunable wavelength light source method has complex structure and high system cost

[0004] At present, the large-capacity fiber grating sensing technology based on wavelength division multiplexing multi-channel and time division multiplexing weak reflection grating has been developed to a certain extent, but there are still technical bottlenecks related to complex system structure, high cost, and low demodulation frequency.

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