Abstract: 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 (1), a 1×2 polarization-maintaining optical-fiber coupler (2), a dual Mach-Zehnder electro-optical modulator (3), an arbitrary waveform generator (4), a first low noise microwave amplifier (5), a second low noise microwave amplifier (6), an electro-optical modulator bias control panel (7), a 1×2 optical-fiber coupler (8), an erbium-doped optical-fiber amplifier (9), an optical-fiber filter (10), an optical-fiber circulator (11), a sensing optical fiber (12), a tricyclic polarization controller (13), a 2×2 optical-fiber coupler (14), a balanced photoelectric detector (15), a data acquisition card (16) and a processing unit (17).

Abstract: 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 (1), a 1×2 polarization-maintaining optical-fiber coupler (2), a dual Mach-Zehnder electro-optical modulator (3), an arbitrary waveform generator (4), a first low noise microwave amplifier (5), a second low noise microwave amplifier (6), an electro-optical modulator bias control panel (7), a 1×2 optical-fiber coupler (8), an erbium-doped optical-fiber amplifier (9), an optical-fiber filter (10), an optical-fiber circulator (11), a sensing optical fiber (12), a tricyclic polarization controller (13), a 2×2 optical-fiber coupler (14), a balanced photoelectric detector (15), a data acquisition card (16) and a processing unit (17).

Abstract: 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.

Abstract: The present invention discloses an optical fiber laying method by using Archimedes spiral in optical frequency domain reflection, wherein the optical fiber laying method comprises the following steps: performing two measurements continuously via a two-dimensional strain sensing device, and performing cross-correlation operation on the two one-dimensional information of the local distance domain, and obtaining the strain variation of the one-dimensional information corresponding to the two measurements from the obtained cross-correlation information; deriving the two-dimensional angle information and curvature radius information of the plane to be measured corresponding to one-dimensional information in the local distance domain based on Archimedes spiral formula; deriving the position coordinates corresponding to the two-dimensional plane based on the curvature radius information and two-dimensional angle information; corresponding the strain variation of the one-dimensional information to the position coordi

Abstract: 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.

Abstract: 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.

Abstract: 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.