公开(公告)号：US20180366897A1

公开(公告)日：2018-12-20

申请号：US16112516

申请日：2018-08-24

Applicant: University of Electronic Science and Technology of China

Inventor： Zinan Wang ,  Jiaqi Li ,  Han Wu ,  Yunjiang Rao

IPC: H01S3/067

Abstract: A random distributed Rayleigh feedback fiber laser based on a double-cladding weakly ytterbium-doped fiber includes: a pump laser source, a pump combiner, a cladding power stripper, and a double-cladding weakly ytterbium-doped fiber for simultaneously achieving distributed active gain and random distributed Rayleigh feedback. An output end of the pump combiner is connected with one end of the double-cladding weakly ytterbium-doped fiber, the other end of the double-cladding weakly ytterbium-doped fiber is connected with an input end of the cladding power stripper, and a concentration of ytterbium ions in the double-cladding weakly ytterbium-doped fiber is in a range of 0.5×1023 to 1×1027/m3. The laser provided by the present invention solves the problem that the existing random fiber lasers cannot simultaneously utilize distributed active gain and random distributed Rayleigh feedback with a single type of fiber.

公开(公告)号：US20180341120A1

公开(公告)日：2018-11-29

申请号：US16035722

申请日：2018-07-16

Applicant: University of Electronic Science and Technology of China

Inventor： Weili Zhang ,  Rui Ma ,  Bo Hu ,  Yunjiang Rao

IPC: G02B27/48 ,  H01S3/067 ,  H01S3/131 ,  H01S3/30

Abstract: A speckle-free imaging light source based on a random fiber laser (RFL) using a strong-coupling multi-core optical fiber, relating to a field of optical fiber laser illumination light source, is provided, mainly including a pumping source and an optical fiber loop mirror, and further including the strong-coupling multi-core optical fiber with/without a single-mode optical fiber. Through directly adopting the strong-coupling multi-core optical fiber or combining the single-mode optical fiber with the strong-coupling multi-core optical fiber to serve as a main device in the RFL-based illumination light source, the generated RFL has multiple transvers modes and low spatial coherence which prevent speckle formation during illumination, which provides an ideal illumination light source for high-speed full-field speckle-free imaging technology.

公开(公告)号：US09841349B2

公开(公告)日：2017-12-12

申请号：US15382671

申请日：2016-12-18

Applicant: University of Electronic Science and Technology of China

Inventor： Zinan Wang ,  Yun Fu ,  Yunjiang Rao

IPC: G01N21/00 ,  G01M11/00

CPC classification number: G01M11/3181

Abstract: A method for distributedly measuring polarization transmission matrices of an optical fiber includes steps of: inputting a fully polarized pulse into the optical fiber with linear birefringence only; and demodulating polarization states of Rayleigh backscattered light at different points on the optical fiber from a pulse input end; after demodulating, dividing the polarization states of the Rayleigh backscattered light into Q groups in sequence, wherein every three polarization states are divided into one group; calculating a transmission matrix of Group N; and solving the equation set using a numerical analysis method for obtaining multiple solutions, and screening the multiple solutions according to characteristics of the polarization transmission matrix, wherein each time of screening provides a unique solution Mx(N) of the equation set; continually updating MA values for iteration, so as to obtain the distribution of polarization transmission matrices of the optical fiber.

公开(公告)号：US10996101B2

公开(公告)日：2021-05-04

申请号：US16289657

申请日：2019-03-01

Applicant: University of Electronic Science and Technology of China

Inventor： Yunjiang Rao ,  Yun Fu

IPC: G01H9/00 ,  H04J14/00 ,  G02B6/42 ,  H04J14/04 ,  G01V8/24 ,  G01V8/16

Abstract: A distributed acoustic sensing (DAS) system based on space-division multiplexing with multi-core fiber (MCF) is proposed. It relates to a technical field of distributed optical fiber sensing. The present invention maintains the advantage of single-ended measurement in the standard DAS system, and realizes the intensity accumulation of the Rayleigh backscattering light within each core of the MCF, which can greatly improve the strain resolution of DAS systems. Moreover, the introduction of optical switch can make different code sequences transmit in the different core of the MCF simultaneously, which can make the single-pulse response with coding gain demodulated without sacrificing the frequency responding bandwidth. Furthermore, the utilization of space-division multiplexing can make multiple pulses with precious time delay transmit in the MCF simultaneously, which can greatly improve the frequency responding bandwidth of DAS system.

公开(公告)号：US10985520B2

公开(公告)日：2021-04-20

申请号：US16427347

申请日：2019-05-31

Applicant: University of Electronic Science and Technology of China

Inventor： Yunjiang Rao ,  Kang Li ,  Bing Han ,  Yun Fu ,  Zengling Ran

IPC: H01S3/067 ,  G01H9/00 ,  G01D5/353 ,  H01S3/094

Abstract: A long-distance FODAS amplification system includes a distributed amplification unit, which includes a LEAF, a pump, and a WDM; wherein the pump light passes through the WDM into the LEAF, so as to realize distributed amplification. A long-distance FODAS amplification method includes steps of: 1) modulating and amplifying a light source to obtain the probe pulse light; 2) guiding the pump light and the probe pulse light into LEAF; 3) combining the probe pulse light with the pump light to perform distributed amplification, so as to generate power-raised Rayleigh backscattered light; and 4) converting and demodulating the Rayleigh backscattered light after being output through the circulator, so as to complete distributed sensing.

公开(公告)号：US20180357542A1

公开(公告)日：2018-12-13

申请号：US16057828

申请日：2018-08-08

Applicant: University of Electronic Science and Technology of China

Inventor： Huijuan Wu ,  Jiping Chen ,  Xiangrong Liu ,  Yao Xiao ,  Mengjiao Wang ,  Bo Tang ,  Mingru Yang ,  Haoyu Qiu ,  Yunjiang Rao

IPC: G06N3/08 ,  G06N3/04 ,  G06F17/18

CPC classification number: G06N3/08 ,  G06F17/18 ,  G06N3/04

Abstract: A 1D-CNN-based ((one-dimensional convolutional neural network)-based) distributed optical fiber sensing signal feature learning and classification method is provided, which solves a problem that an existing distributed optical fiber sensing system has poor adaptive ability to a complex and changing environment and consumes time and effort due to adoption of manually extracted distinguishable event features, The method includes steps of: segmenting time sequences of distributed optical fiber sensing acoustic and vibration signals acquired at all spatial points, and building a typical event signal dataset; constructing a 1D-CNN model, conducting iterative update training of the network through typical event signals in a training dataset to obtain optimal network parameters, and learning and extracting 1D-CNN distinguishable features of different types of events through an optimal network to obtain typical event signal feature sets; and after training different types of classifiers through the typical event signal feature sets, screening out an optimal classifier.

公开(公告)号：US20180080812A1

公开(公告)日：2018-03-22

申请号：US15812996

申请日：2017-11-14

Applicant: University of Electronic Science and Technology of China

Inventor： Huijuan Wu ,  Wei Zhang ,  Xiangrong Liu ,  Yunjiang Rao

IPC: G01H9/00 ,  G01V1/18 ,  G01V1/28

CPC classification number: G01H9/004 ,  G01V1/18 ,  G01V1/208 ,  G01V1/226 ,  G01V1/288 ,  G06F17/12 ,  G06N5/04 ,  G06N7/005 ,  H04B10/25

Abstract: A distributed optical fiber sensing signal processing method for safety monitoring of underground pipe network, which belongs to infrastructure safety monitoring field, which is aimed to improve the intelligent ability of detection and identification of the existing distributed optical fiber sound/vibration sensing system under complex application conditions. The present invention utilizes the distributed optical fiber sound/vibration sensing system to pick up the sound or vibration signal of the whole line along the detection cable; and the customized short time feature and long time feature are respectively extracted from the relative quantity of the sound or the vibration signal at each spatial point in the whole monitoring range. The Bayesian identification and classification network at each spatial point is constructed and trained based on the prior knowledge of the collected signal features and their different background noises.

公开(公告)号：US20170097281A1

公开(公告)日：2017-04-06

申请号：US15382671

申请日：2016-12-18

Applicant: University of Electronic Science and Technology of China

Inventor： Zinan Wang ,  Yun Fu ,  Yunjiang Rao

IPC: G01M11/00 ,  G01N21/47 ,  G01N21/21

CPC classification number: G01M11/3181

Abstract: A method for distributedly measuring polarization transmission matrices of an optical fiber includes steps of: inputting a fully polarized pulse into the optical fiber with linear birefringence only; and demodulating polarization states of Rayleigh backscattered light at different points on the optical fiber from a pulse input end; after demodulating, dividing the polarization states of the Rayleigh backscattered light into Q groups in sequence, wherein every three polarization states are divided into one group; calculating a transmission matrix of Group N; and solving the equation set using a numerical analysis method for obtaining multiple solutions, and screening the multiple solutions according to characteristics of the polarization transmission matrix, wherein each time of screening provides a unique solution Mx(N) of the equation set; continually updating MA values for iteration, so as to obtain the distribution of polarization transmission matrices of the optical fiber.