公开(公告)号：US11181400B2

公开(公告)日：2021-11-23

申请号：US16324275

申请日：2016-10-27

Applicant: Tianjin University

Inventor： Junfeng Jiang ,  Tiegen Liu ,  Jinling Yan ,  Kun Liu ,  Shuang Wang ,  Xuezhi Zhang ,  Chuanjun Zang ,  Renwei Xie ,  Qiliang Chu

IPC: G01D5/353 ,  G01D3/028 ,  G01D18/00

Abstract: 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 (1), an optical attenuator (2), a tunable F-P filter (3), a first optical fiber isolator (41), an erbium-doped optical fiber amplifier (5), an optical fiber first-stage beam splitter (6), a first optical fiber second-stage beam splitter (71), optical fiber circulators (8), FBG sensor arrays (9), a first photoelectric detector array (161), an optical fiber gas cell (10), a second optical fiber second-stage beam splitter (72), an optical fiber F-P etalon (11), a notch filter (12), an optical fiber assisted interferometer (13), a data acquisition card (17) and a processor (18).

公开(公告)号：US12078527B2

公开(公告)日：2024-09-03

申请号：US17630408

申请日：2020-01-22

Applicant: TIANJIN UNIVERSITY

Inventor： Junfeng Jiang ,  Tiegen Liu ,  Zhe Ma ,  Shuang Wang ,  Kun Liu ,  Zhenyang Ding ,  Xuezhi Zhang ,  Wenjie Chen ,  Guanhua Liang

IPC: G01H9/00 ,  G01D5/353 ,  G01H1/00 ,  G01N29/24

CPC classification number: G01H9/004 ,  G01D5/35329 ,  G01D5/35361 ,  G01H1/006 ,  G01H9/00 ,  G01N29/2418 ,  G01N2291/0423

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). 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.