High-frequency vibration distributed optical fiber sensing system based on random sampling

Abstract

The invention discloses a high-frequency vibration distributed optical fiber sensing system based on random sampling. The system comprises a laser device, an intensity modulator, a circulator and a detector. The laser device is used for producing continuous laser signals. The intensity modulator is used for receiving the laser signals and modulating the laser signals into random pulsed light. The first end of the circulator is used for receiving the random pulsed light, the second end of the circulator is used for injecting the random pulsed light into a sensing optical fiber and receiving Rayleigh scattering light transmitted reversely in the sensing optical fiber, and the third end of the circulator is sued for outputting the Rayleigh scattering light. The detector is used for converting the Rayleigh scattering light into electric signals. The system can greatly widen the frequency response range, the vibration frequency response range is not limited by sensing distance, high-frequency vibration is facilitated, and particularly wide-spectrum vibration with the frequency sparse characteristic is effectively detected.

Description

technical field [0001] The invention relates to the field of optical fiber sensing, in particular to a high-frequency vibration distributed optical fiber sensing system based on random sampling. Background technique [0002] In the health monitoring and diagnosis of major projects and infrastructures such as large-scale building structures, aerospace, petrochemical, and power systems, optical fiber sensing technology has gradually gained popularity due to its small sensitive components, high durability, absolute measurement, and distributed monitoring. It is a trend to replace electrical sensors as the preferred sensitive components for sensor health monitoring. Among them, the technical research and application of distributed monitoring of vibration over long distances using optical fibers is continuously deepening. [0003] In the prior art, the optical fiber vibration distributed sensing system generally uses a uniform sampling method to sample vibration events. Since th...

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Problems solved by technology

[0003] In the prior art, the optical fiber vibration distributed sensing system generally uses a uniform sampling method to sample vibration events. Since the sampling rate in the system is limited by the round-trip time of pulsed light, the vibration frequency response range of the system is often limited to low frequencies, and the transmission The longer the sensing distance, the narrower the vibration frequency response range of the system

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