A novel time/wavelength-multiplexed fiber Bragg grating sensor array is presented. This type of sensor array has the advantages of more points for multi-point measurement, simple structure and low cost.
A two-dimensional(2D) optical true-time delay(TTD) beam-forming system using a compact fiber grating prism(FGP) for a planar phased array antenna(PAA) is proposed. The optical beam-forming system mainly consists of a ...A two-dimensional(2D) optical true-time delay(TTD) beam-forming system using a compact fiber grating prism(FGP) for a planar phased array antenna(PAA) is proposed. The optical beam-forming system mainly consists of a TTD unit based on the same compact FGP, one tunable laser for elevation beam steering, and a controlled wavelength converter for azimuth beam steering. A planar PAA using such 2D optical TTD unit has advantages such as compactness, low bandwidth requirement for tunable laser sources, and potential for large-scale system implementations. The proof-of-concept experiment results demonstrate the feasibility of the proposed scheme.展开更多
Two array waveguide grating (AWGs) based fiber ring lasers are experimentally demonstrated. Either of them achieves wavelength discrete tuning of 32 nm, or yields simultaneously lasing up to four channels with -7 dBm ...Two array waveguide grating (AWGs) based fiber ring lasers are experimentally demonstrated. Either of them achieves wavelength discrete tuning of 32 nm, or yields simultaneously lasing up to four channels with -7 dBm output power for each channel.展开更多
This article presents a high-speed distributed vibration sensing based on Mach-Zehnder-OTDR （optical time-domain reflectometry）. Ultra-weak fiber Bragg gratings （UWFBG）, whose backward light intensity is 2-4 order...This article presents a high-speed distributed vibration sensing based on Mach-Zehnder-OTDR （optical time-domain reflectometry）. Ultra-weak fiber Bragg gratings （UWFBG）, whose backward light intensity is 2-4 orders of magnitude higher than that of Rayleigh scattering, are used as the reflection markers. A medium-coherence laser can substitute conventional narrow bandwidth source to achieve an excellent performance of distributed vibration sensing since our unbalanced interferometer matches the interval of UWFBGs. The 3 m of spatial resolution of coherent detection and multiple simultaneous vibration sources locating can be realized based on OTDR. The enhanced signal to noise ratio （SNR） enables fast detection of distributed vibration without averaging. The fastest vibration of 25 kHz and the slowest vibration of 10Hz can be detected with our system successfully, and the linearity is 0.9896 with a maximum deviation of 3.46nε.展开更多
基金Supported by Beijing Education Administration Foundation (00KG040)
文摘A novel time/wavelength-multiplexed fiber Bragg grating sensor array is presented. This type of sensor array has the advantages of more points for multi-point measurement, simple structure and low cost.
基金supported by the National "973" Project of China(Nos.2010CB328202,2010CB328204,and 2012CB315604)the National Natural Science Foundation of China(Nos.61271191 and 61001124)+3 种基金the National "863" Project of China(No.2012AA011302)the Program for New Century Excellent Talents in University(No.NCET-12-0793)the Beijing Nova Program(No.2011065)the Fundamental Research Funds for the Central Universities
文摘A two-dimensional(2D) optical true-time delay(TTD) beam-forming system using a compact fiber grating prism(FGP) for a planar phased array antenna(PAA) is proposed. The optical beam-forming system mainly consists of a TTD unit based on the same compact FGP, one tunable laser for elevation beam steering, and a controlled wavelength converter for azimuth beam steering. A planar PAA using such 2D optical TTD unit has advantages such as compactness, low bandwidth requirement for tunable laser sources, and potential for large-scale system implementations. The proof-of-concept experiment results demonstrate the feasibility of the proposed scheme.
文摘Two array waveguide grating (AWGs) based fiber ring lasers are experimentally demonstrated. Either of them achieves wavelength discrete tuning of 32 nm, or yields simultaneously lasing up to four channels with -7 dBm output power for each channel.
基金This work was supported in part by the National Natural Science Foundation of China （Gram No. 61735031）, Natural Science Foundation of Hubei Province of China （Grant No. 2018CFA056）, and the Excellent Dissertation Cultivation Funds of Wuhan University of Technology （Grant No. 2017-YS-057）.
文摘This article presents a high-speed distributed vibration sensing based on Mach-Zehnder-OTDR （optical time-domain reflectometry）. Ultra-weak fiber Bragg gratings （UWFBG）, whose backward light intensity is 2-4 orders of magnitude higher than that of Rayleigh scattering, are used as the reflection markers. A medium-coherence laser can substitute conventional narrow bandwidth source to achieve an excellent performance of distributed vibration sensing since our unbalanced interferometer matches the interval of UWFBGs. The 3 m of spatial resolution of coherent detection and multiple simultaneous vibration sources locating can be realized based on OTDR. The enhanced signal to noise ratio （SNR） enables fast detection of distributed vibration without averaging. The fastest vibration of 25 kHz and the slowest vibration of 10Hz can be detected with our system successfully, and the linearity is 0.9896 with a maximum deviation of 3.46nε.
