Optical fiber radiation sensing system and sensing method thereof

Abstract

The invention provides an optical fiber radiation sensing system and a sensing method thereof. The optical fiber radiation sensing system comprises a light source, an optical fiber circulator, an light receiving unit, a high-speed (active directory) AD collection card and a microprocessor system. The sensing method comprises the following steps of: generating an optical pulse and a synchronizing signal by the light source; generating backward rayleigh scattering light by the optimal pulse after passing through the optical fiber circulator to enter sensing optical fiber; enabling the rayleigh scattering light to enter the light receiving unit to be converted into an electrical signal and finally enter the high-speed AD collection card; controlling the collection of the rayleigh scattering light electrical signal by the high-speed AD collection card by the synchronizing signal and carrying out data pretreatment, data calibration, data demodulation and data correction on data; and receiving the data pretreated by the high-speed AD collection card by the microprocessor system. The optical fiber radiation sensing system and the sensing method thereof have high positioning precision of an optical time domain reflectometry technology and good absorption loss change sensitivity of optical fiber materials due to dry radiation.

Description

Technical field [0001] The invention relates to the technical field of optical fiber sensing, and in particular to an optical fiber radiation sensing system and a sensing method thereof. Background technique [0002] The concept of fiber optic sensors is not new. The first patent appeared in the mid-1960s, which included a Fotonic mechanical displacement sensor using a beam transmission and an ultrasonic sensor using phase modulation. However, in a broader field, namely, optical fiber sensing technology, a series of research was achieved 10 years later. Since then, optical fiber technology has broken through the lingering state and entered an era of rapid development. [0003] The basic principle of the optical fiber sensor is: the light emitted by the light source enters the modulation area through the optical fiber. Under the action of the measured object, the optical properties such as the intensity, wavelength, frequency, phase and polarization state of the light change, making...

AI Technical Summary

Problems solved by technology

However, the detection area of ​​the positioning-type ultra-large-length distributed optical fiber radiation sensor is very large, and the longer the measuring optical cable, the better, generally greater than 50Km, and the spatial resolution of the defense zone is 1m, so the dynamic range of light receiving of the system is very wide (greater than 50dB). The processing system requirements are extremely high, so a precise positioning type ultra-large length distributed optical fiber radiation sensing method with stable performance is required

Images