Measurement Method of Phase Sensitive OTDR Based on Frequency-Space Domain Matching and Injection Locking Technology

Abstract

The invention provides a phase-sensitive OTDR and measurement method based on frequency-space domain matching and injection locking technology. The phase-sensitive OTDR includes a pulsed light sequence generating device and an echo signal detection device; the pulsed light sequence generating device includes a master laser, a slave laser, an electro-optic modulator, an acousto-optic modulator, an arbitrary waveform generator, an arbitrary function generator and a first The circulator; the echo signal detection device includes a first erbium-doped fiber amplifier, a second circulator, a second erbium-doped fiber amplifier and a photodetector. The above technology uses arbitrary wave modulation injection locking technology to realize fast tuning of laser frequency, fundamentally avoids nonlinear problems in the frequency scanning process, and has high-precision sensing capabilities. The present invention adopts the frequency domain-space domain matching technology for data demodulation, and by matching the frequency domain information of multiple air domain points, it can significantly reduce the demand for data demodulation on the number of frequency domain points, greatly reduce the requirements for hardware bandwidth, and expand the Measuring range.

Description

technical field [0001] Embodiments of the present invention relate to the field of sensing technology, and more specifically, embodiments of the present invention relate to a measurement method of a phase-sensitive OTDR based on frequency-space domain matching and injection locking technology. Background technique [0002] Compared with other distributed sensing technologies, phase-sensitive optical time domain reflectometer (Φ-OTDR) technology based on Rayleigh scattering effect has the advantages of simple structure and high sensitivity. This technology injects laser pulses with a narrow linewidth into the optical fiber to obtain the interference superposition signal of the back Rayleigh scattered light within half the pulse width, and the interference superposition signal is extremely sensitive to changes in external temperature or strain. The intensity variation of the echo signal shows that the response sensitivity of temperature or strain can reach the order of mK and ...

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Problems solved by technology

[0004] In this context, the embodiments of the present invention expect to provide a phase-sensitive OTDR and measurement method based on frequency-space domain matching and injection locking technology, so as to solve the problem of small measurement range and The problem of large bandwidth requirements, so as to realize the dynamic measurement of temperature or strain with large range and high sensitivity

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