Tianjin University

Zhenyang Ding

Junfeng Jiang

Tiegen Liu

Kun Liu

Shuang Wang

Xuezhi Zhang

Zhexi Xu

Dingjie Li

Zhe Ma

Wenjie Chen

Di Yang

Guanhua Liang

Yang Du

The present invention discloses a differential COTDR distributed acoustic sensing device based on heterogeneous double-sideband chirped-pulses of the invention, comprising a light source (), a 1×2 polarization-maintaining optical-fiber coupler (), a dual Mach-Zehnder electro-optical modulator (), an arbitrary waveform generator (), a first low noise microwave amplifier (), a second low noise microwave amplifier (), an electro-optical modulator bias control panel (), a 1×2 optical-fiber coupler (), an erbium-doped optical-fiber amplifier (), an optical-fiber filter (), an optical-fiber circulator (), a sensing optical fiber (), a tricyclic polarization controller (), a 2×2 optical-fiber coupler (), a balanced photoelectric detector (), a data acquisition card () and a processing unit (). The present invention combines heterogeneous double-sideband chirped-pulse modulation and coherent light time-domain reflection technology, so as to double the sensitivity of the to-be-measured acoustic wave signal and to suppress common-mode noise, and further improves SNR.

Differential COTDR distributed acoustic sensing device and method based on heterogeneous double-sideband chirped-pulses

The present invention discloses a distributed device for simultaneously measuring strain and temperature based on optical frequency domain reflection, comprising a tunable laser, a 1:99 beam splitter, a main interferometer system, a light source phase monitoring system based on an auxiliary interferometer, an acquisition device and a computer processing unit, wherein the main interferometer system comprises two Mach-Zehnder interferometers, and two optical fibers having different cladding diameters are arranged in parallel as sensing fibers. Due to the difference in temperature and strain coefficients of optical fibers of the same diameter, the temperature and strain values during changing the temperature and strain simultaneously can be obtained by matrix operation, thereby achieving an effect of eliminating cross sensitivity of temperature and strain sensing in optical frequency domain reflection.

Distributed measuring device and method for simultaneously measuring strain and temperature based on optical frequency domain reflection

This invention relates to a distributed disturbance sensing device based on polarization sensitive optical frequency domain reflectometry (OFDR) and the related demodulation thereof. The device, adopting OFDR, polarization controlling and analysis techniques, consists of a ultra-narrow linewidth tunable laser source module, polarization generating and polarization splitting balanced detecting module, laser source optical frequency and phase monitoring module, high-speed optical switch and so on to establish a large-scale and long-distance optical sensing network. The demodulation method consists of analysis the polarization information from sensing optical fiber, the method of suppressing and compensating of the non-linear optical frequency and the laser phase noise, super-resolution analyzing, advanced denoising method and the polarization information analysis method based on Jones and Mueller's matrices using distributed wave plate model of optical fiber.

Distributed disturbance sensing device and the related demodulation method based on polarization sensitive optical frequency domain reflectometry

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Tianjin, China

Zhenyang Ding