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1.发明申请公开(公告)号：US20190288475A1
公开(公告)日：2019-09-19
申请号：US16427347
申请日：2019-05-31
Inventor： Yunjiang Rao , Kang Li , Bing Han , Yun Fu , Zengling Ran
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.
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2.发明申请公开(公告)号：US20190226908A1
公开(公告)日：2019-07-25
申请号：US16289657
申请日：2019-03-01
Inventor： Yunjiang Rao , Yun Fu
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.
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Patent Agency Ranking
3.发明申请公开(公告)号：US20190058524A1
公开(公告)日：2019-02-21
申请号：US16166096
申请日：2018-10-20
Inventor： Yunjiang Rao , Yun Fu , Jiaqi Li , Zinan Wang
Abstract: A hybrid distributed amplification method based on a random fiber laser generated within erbium fiber with low doping concentration, i.e. weak erbium-doped fiber (WEDF), which includes: Step 1. constructing a fiber link via WEDF; Step 2. generating the random fiber laser based on the fiber link, the pump source, the wavelength division multiplexer and the strong feedback module; Step 3. constructing the spatial equalized gain based on hybrid gain of the erbium fiber and random fiber laser; Step 4. the signal is amplified by the hybrid spatial equalized gain. The present invention solves the typical problem of high laser threshold and low pump conversion efficiency when conventional fiber is used to generate random fiber laser for distributed amplification.
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公开(公告)号：US09841349B2
公开(公告)日：2017-12-12
申请号：US15382671
申请日：2016-12-18
Inventor： Zinan Wang , Yun Fu , Yunjiang Rao
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.
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5.发明授权公开(公告)号：US10996101B2
公开(公告)日：2021-05-04
申请号：US16289657
申请日：2019-03-01
Inventor： Yunjiang Rao , Yun Fu
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.
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6.发明授权公开(公告)号：US10985520B2
公开(公告)日：2021-04-20
申请号：US16427347
申请日：2019-05-31
Inventor： Yunjiang Rao , Kang Li , Bing Han , Yun Fu , Zengling Ran
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.
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7.发明申请公开(公告)号：US20170097281A1
公开(公告)日：2017-04-06
申请号：US15382671
申请日：2016-12-18
Inventor： Zinan Wang , Yun Fu , Yunjiang Rao
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.
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