Fiber bragg grating vibration measurement system based on pulse coding and edge filtering method

Abstract

The invention provides a fiber bragg grating vibration measurement system based on a pulse coding and edge filtering method and belongs to the technical field of fiber bragg grating sensors. The system comprises a narrow linewidth laser, a pulse signal generator, an electrooptical modulator, a circulator, a single mode fiber, a fiber bragg grating, a photoelectric detector and a digital signal processing unit, wherein an output end of the narrow linewidth laser is connected with an optical input end of the electrooptical modulator, an output end of the pulse signal generator is connected witha radio frequency input end of the electrooptical modulator, an output end of the electrooptical modulator is connected with a first port of the circulator, a second port of the circulator is sequentially connected with the single mode fiber and the fiber bragg grating, the photoelectric detector is connected with a third port of the circulator, and the digital signal processing unit is connectedwith the photoelectric detector. The fiber bragg grating vibration measurement system prepared according to pulse coding principles and edge filtering principles has monitoring and measurement functions of an OTDR (optical time domain reflectometer), and the conflict that the sensing distance and the spatial resolution in an OTDR system cannot be improved simultaneously is eradicated.

Description

technical field [0001] The invention relates to the technical field of fiber grating sensors, in particular to a fiber grating vibration measurement system based on pulse coding and edge filtering. Background technique [0002] Vibration is an important parameter that reflects the normal state of an object, such as the vibration of a bridge, the vibration of a large instrument when it is working, etc. When the vibration exceeds a certain range, it may bring serious consequences, so the measurement of vibration is very important for the health monitoring of large structures . Fiber Bragg grating sensors have been widely concerned and applied because of their strong anti-electromagnetic interference ability, corrosion resistance, small size, and high sensitivity, such as for building health monitoring, aircraft structure safety monitoring, land subsidence and earthquake real-time monitoring, etc. When the fiber grating is used for vibration monitoring, the sensor is embedded ...

AI Technical Summary

Problems solved by technology

[0003] When performing detection, such as monitoring high-risk areas such as earthquakes and volcanoes, the common fiber grating vibration sensor feedback signal attenuation is serious and the signal-to-noise ratio is low, the measurement distance is easily limited, and the accuracy of the measurement results is not high enough

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