Realization apparatus and method for distributed optical fiber sensing system based on single photon detection

Abstract

The invention discloses a realization apparatus and method for a width dynamic scope distributed optical fiber sensing system based on single photon detection. A single-photon detector is employed to replace a conventional photo-detector, so that the detection sensitivity of the system is improved. The real-time shaping of the return signal amplitude of sensing fibers using an optical intensity modulator is realized, which solves the problem of small dynamic range due to the fact that the saturation light intensity of the single-photon detector is too low and improves the sensing distance of the optical fiber. The structural principle lies in that a laser injects laser pulses in the sensing fiber via a circulator, backscattered light carrying the sensing information is re-introduced through the circulator into the light intensity modulator, and a waveform generator outputs a drive signal synchronized with the backscattered optical signal to control the attenuation value of the optical intensity modulator. The attenuated light signal is detected by the single-photon detector. A signal processing unit restores the intensity of the original signal light according to the attenuation value of the optical intensity modulator and the output value of the single-photon detector, thereby realizing the wide dynamic range distributed optical fiber sensing.

Description

technical field [0001] The invention relates to the technical field of optical fiber sensing, and more specifically, to a device and method for realizing a wide dynamic range distributed optical fiber sensing system based on single photon detection. Background technique [0002] Distributed optical fiber sensing technology uses the geometric one-dimensional characteristics of the optical fiber to measure. The optical fiber is used as both a sensing element and a transmission element. The continuous measurement of the parameters provides a means to simultaneously obtain the information of the measured physical parameters changing with space and time. Its most notable advantage is that it can accurately measure information such as stress, temperature, vibration and damage at any point along the optical fiber without forming a loop. The measured one-dimensional distribution in the entire optical fiber area can be obtained by one measurement, and the measured two-dimensional or...

AI Technical Summary

Problems solved by technology

This method uses a single photon detector to replace the traditional light detector, which improves the detection sensitivity of the system; uses an optical intensity modulator to shape the amplitude of the return signal of the sensing fiber in real time, and overcomes the problem caused by the low saturation light intensity of the single photon detector. The problem of small dynamic range, improve the optical fiber sensing distance

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