phase-sensitive OTDR and a measurement method based on frequency-domain matching and injection locking technolo

Abstract

The invention provides a phase-sensitive OTDR and a measurement method based on a frequency-domain matching and injection locking technology. The phase-sensitive OTDR includes a pulse light sequence generating device and an echo signal detecting device; the pulse light sequence generating device includes a main laser, a slave laser, an electro-optic modulator, an acousto-optic modulator, an arbitrary waveform generator, an arbitrary function generator and the first circulator; the echo signal detecting device includes a first erbium doped fiber amplifier, a second circulator, a second erbium doped fiber amplifier and a photodetector. The above technology adopts an arbitrary wave modulation injection locking technology to achieve fast tuning of the laser frequency to fundamentally avoid thenonlinear problems in the frequency scanning process and has high-precision sensing capability. The demodulation of the data adopts the frequency domain-space matching technology, and the frequency-domain information of the multi-space domain is matched to significantly reduce the requirement of the data demodulation on the frequency domain points, thereby greatly reducing the requirement on thehardware bandwidth and expanding the measurement 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 phase-sensitive OTDR and measurement method 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 n...

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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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