Tianjin University

Shuang Wang

Junfeng Jiang

Tiegen Liu

Kun Liu

Xuezhi Zhang

Zhenyang Ding

Guanhua Liang

Huijia Yang

Weihang Zhang

Chuanjun Zang

Xue Wang

Mengnan Xiao

Wenjie Chen

Qiliang Chu

Dongdong Ju

Jinling Yan

Renwei Xie

Zhe Ma

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 residual pressure measurement system for a MEMS pressure sensor with an F-P cavity and method thereof, the measurement system includes a low-coherence light source, a 3 dB coupler, a MEMS pressure sensor, an air pressure chamber, a thermostat, a pressure control system, a cavity length demodulator, an acquisition card and a computer. The measurement method comprises: performing cavity length measurement by using the reflecting light by the pressure control system at two temperatures, respectively, so as to calibrate the MEMS pressure sensor and establish a relationship between the absolute phase of a monochromatic frequency and the external pressure; performing linear fitting to the two measurement data to obtain all the external pressure when the cavity length of two measurement data are equal to each other, and substituting the theoretical equation for calculation to obtain the residual pressure under the flat condition of the diaphragm.

Residual pressure measurement system for Fabry-Perot cavity of optical MEMS pressure sensor and method thereof

The present invention discloses a Fiber Bragg Grating demodulation device with a suppressed fluctuation at a variable ambient temperature and a demodulation method. The device comprises a broadband light source (), an optical attenuator (), a tunable F-P filter (), a first optical fiber isolator (), an erbium-doped optical fiber amplifier (), an optical fiber first-stage beam splitter (), a first optical fiber second-stage beam splitter (), optical fiber circulators (), FBG sensor arrays (), a first photoelectric detector array (), an optical fiber gas cell (), a second optical fiber second-stage beam splitter (), an optical fiber F-P etalon (), a notch filter (), an optical fiber assisted interferometer (), a data acquisition card () and a processor ().

Fiber Bragg Grating demodulation device capable of supressing fluctuations at variable ambient temperature and demodulation method thereof

Fiber optical Fabry-Perot flow test device with local bending diversion structure, having an inlet flange, a test tube and an outlet flange, with both a fiber optical Fabry-Perot pressure sensor at high-pressure-side and a fiber optical Fabry-Perot pressure sensor at low-pressure-side, which are fixedly connected to the test tube through an auxiliary connecting device.

Fiber optical fabry-perot flow test device and test method with local bending diversion structure

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Tianjin, China

Shuang Wang