Distributed sensing system based on weak Bragg reflection structure

Abstract

The invention discloses a distributed sensing system based on a weak Bragg reflection structure. The distributed sensing system comprises a SG-DBR (Screen Grid-Distributed Bragg Reflector) tunable laser (1), an electrooptic modulator (4), an opto-isolator (5), an optical circulator (6), and weak Bragg reflection cycle structural optical fibers (7), which are connected in turn; wherein the SG-DBR tunable laser (1) is controlled by a wavelength tuning control circuit (2), the electrooptic modulator (4) is controlled by an impulse function generator (3), a photo-detector (8) is connected with the optical circulator (6), control signals outputted by the wavelength tuning control circuit (2) and the electrooptic modulator (4) and electric signals outputted by the photo-detector (8) enter a data acquisition card (9) jointly, and are processed and then transmitted to a data processing device (10). The distributed sensing system realizes the long-distance distributed sensing alarm for parameters such as temperature, stress and vibration, and has the characteristics of higher detection sensitivity and positioning precision, easiness for realization, lower cost and reliability for operation.

Description

technical field [0001] The invention relates to the field of sensing technology, in particular to the application of weak Bragg reflection periodic structure optical fiber in distributed sensing. Based on the continuous backscattering effect and wavelength modulation sensing characteristics of distributed optical fibers, it combines the innovative technology of "Optical Wavelength Time Domain Reflectometry (OWTDR)" for parameter detection and positioning, and obtains the spatial field distribution of the parameters to be measured along the optical fiber. Distributed sensing and alarm system based on weak Bragg reflection structured optical fiber. Background technique [0002] The intelligence of materials and structures is a challenging topic in the 21st century. The use of intelligent structure analysis to monitor engineering structure damage and evaluate the working status of high-risk equipment is of great significance to prevent catastrophic accidents and protect the sa...

AI Technical Summary

Problems solved by technology

However, a major problem faced by FBG-based distributed sensing is that the multiplexing capacity of the system is limited by the bandwidth of the light source and the filter. Generally, an array can only multiplex about 15 gratings. is not enough

Therefore, the research on fiber grating multiplexing technology has received widespread attention. This method solves the problem that the number of multiplexing in wavelength division multiplexing technology is limited by the bandwidth of the light source and wavelength demodulator, but it still needs to demodulate the reflected light wavelength to determine the maximum temperature. , and the biggest disadvantage is that it is impossible to distinguish the specific location where the overheating occurs

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