Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2020 ( 2 )

2019 ( 3 )

2018 ( 12 )

2017 ( 5 )

Custom range...

Search Results: 1 - 10 of 559 matches for " extrinsic Fabry-Perot interferometer "
All listed articles are free for downloading (OA Articles)
Page 1 /559
Display every page Item
Recent developments in fiber optic spectral white-light interferometry
Yi Jiang,Wenhui Ding
Photonic Sensors , 2011, DOI: 10.1007/s13320-010-0014-z
Abstract: Recent developments in spectral white-light interferometry (WLI) are reviewed. Firstly, the techniques for obtaining optical spectrum are introduced. Secondly, some novel measurement techniques are reviewed, including the improved peak-to-peak WLI, improved wavelength-tracking WLI, Fourier transform WLI, and 3 × 3 coupler based WLI. Furthermore, a hybrid measurement for the intensity-type sensors, interferometric sensors, and fiber Bragg grating sensors is achieved. It is shown that these developments have assisted in the progress of WLI.
Study on the Method of Improving EFPI''''s Signal Quality

(Opto-electronic Engineering,

光子学报 , 2004,
Abstract: The measurement accuracy of EFPI (Extrinsic Fabry Perot Interferometers) strain sensor is affected by the quality of its output signal. However whatever kind of demodulation algorithm is adopted, a poor interferential pattern with low contrast and low amplitude always leads to a rough measurement result. To address this problem, the signal quality of EFPIs with different end reflectivity was theoretically analyzed in this paper. Computer simulation indicated that the signal quality could be improved by increasing the reflectivity of fiber ends in the F P cavity. This is also experimentally demonstrated by vaporization coating to each fiber end.
White Light Interferometry for the Measurement of Extrinsic Fabry-Perot Interferometer

Jiang Yi,

光子学报 , 2006,
Abstract: The white light interferometry for the measurement of low-finesse extrinsic Fabry-Perot interferometer(EFPI) is reported. A broadband light is injected into EFPI,and the reflected light is scanned by another high-finesse tunable Fabry-Perot filter,the periodic spectra of EFPI can be obtained.To measure the cavity length,the spectra are fast Fourier transformed,the absolute length of cavity can be calculated by using the periodic spectra. The measuring accuracy is limited by the length of cavity. The longer cavity has higher measuring accuracy. When the length of cavity are 200 μm,400 μm,and 600 μm respectively,the measured results are agree with the actual length of the cavity.
The Design and Realization of an Optic Fibre F-P Acoustic Emission Sensor

YUAN Xiao-qing,SHI Yi-kai,DENG Liang,

光子学报 , 2008,
Abstract: In order to overcome the disadvantages of the piezoelectric ceramic sensor, i. e. susceptibility of electromagnetic disturbance and difficulty of real-time measurement,an extrinsic F-P interferometer sensor is offered . The principle for measuring AE signal of the fibre Extrinsic F-P interferometer instrument is analyzed. The stabilization method of the dual-wavelength is proposed. The structural parameter of this system is designed by optimal design with MATLAB 6. The F-P cavity length,reflectance and wavelength are confirmed. Theoretical analysis and experimental results indicate that the optic fiber extrinsic F-P interferometer AE sensor has refined sensitivity and high resolution, which provides a brand-new and effective way to measure AE signal.
First observation of mesospheric and thermospheric winds by a Fabry-Perot interferometer in China
Wei Yuan,JiYao Xu,RuiPing Ma,Qian Wu,GuoYing Jiang,Hong Gao,Xiao Liu,SunZheng Chen
Chinese Science Bulletin , 2010, DOI: 10.1007/s11434-010-4192-2
Abstract: A Fabry-Perot interferometer, funded by the Meridian Project in China, was deployed at the Xinglong station (40.2°N,117.4°E) of the National Astronomical Observatories in Hebei Province, China. The instrument has been operating since April 2010, measuring mesospheric and thermospheric winds. The first observational data of winds at three heights in the mesosphere and thermosphere were analyzed, demonstrating the capacity of this instrument to aid basic scientific research. The wavelengths of three airglow emissions were OH892.0, OI 557.7, and OI 630.0 nm, which corresponded to heights of 87, 98, and 250 km, respectively. Three 38-day data sets of horizontal winds, from April 5, 2010 to May 12, 2010, show clear day-to-day variations at the same height. The minimum and maximum meridional winds at heights of 87, 98, and 250 km were 16.5 to 8.7 m/s, 24.4 to 15.9 m/s, and 43.6 to 1.5 m/s. Measurements of zonal winds were 5.4 to 7.6 m/s, 2.3 to 23.0 m/s, and 22.6 to 49.3 m/s. The average data from the observations was consistent with the data from HWM93. The wind data at heights of 87 and 98 km suggest a semi-diurnal oscillation, clearly consistent with HWM93 results. Conversely there was a clear discrepancy between the observations and the model at 250 km. In general, this Fabry-Perot interferometer is a useful ground-based instrument for measuring mesospheric and thermospheric winds at middle latitudes.
First observation of thermospheric neutral wind at Chinese Yellow River Station in Ny- lesund, Svalbard
Hong Zhang,Yong Ai,YanGe Zhang,GuoYuan Hu
Chinese Science Bulletin , 2013, DOI: 10.1007/s11434-012-5626-9
Abstract: A compact and cost-effective all-sky Fabry-Perot interferometer, which is produced by Wuhan University and used for the observation of the thermospheric neutral wind, was installed at Chinese Yellow River Station in Ny- lesund, Svalbard in November 2010, and continuously operated in last two winter seasons. The 92-day all-sky interference data acquired from November 1, 2011 to February 26, 2012 were collected to get the velocity of thermospheric neutral wind, which was calculated from the Doppler shift caused by the movement of oxygen atom at the different layers. The database was divided into two periods: (1) The OI 557.7 nm emission was observed from November 1, 2011 to January 12, 2012. Observations showed that the velocity of horizontal wind is normally less than ~40 m/s on the quiet condition, and exceeded 100 m/s on the disturbed condition; and (2) the OI 630.0 nm emission was observed from January 13, 2012 to February 26, 2012. Observations showed that the velocity of horizontal wind is normally less than ~200 m/s, and enhanced to over 300 m/s on strong magnetic activities. It shows that the velocities of meridional and zonal wind are more consistent with the velocities calculated from the model HWM07 at the higher layer, especially for the zonal direction at nightside auroral regions. Ion drag and Joule heating were the two important processes considered in the analysis of the relationship between the wind pattern and aurora, suggesting that wind speed would be increased and accelerated in the direction perpendicular to the aurora arc when the aurora activity becomes strong.
Fibre Optic Protection System for Concrete Structures

材料科学技术学报 , 2006,
Abstract: The design concepts, modelling and implementation of various fibre optic sensor protection systems for development in concrete structures were investigated. Design concepts and on-site requirements for surface-mounted and embedded optical fibre sensor in concrete were addressed. Finite element (FE) modelling of selected sensor protection systems in strain-transfer efficiency from the structure to the sensing region was also studied. And experimental validation of specified sensor protection system was reported. Results obtained indicate that the protection system for the sensors performs adequately in concrete environment and there is very good correlation between results obtained by the protected fibre optic sensors and conventional electrical resistance strain gauges.
Demodulation error and influencing factor of three-wavelength digital phase demodulation method

- , 2017, DOI: 10.13700/j.bh.1001-5965.2016.0568
Abstract: 摘要 介绍了光纤法布里-珀罗(F-P)传感器的传统解调方法,系统地推导了针对非本征法布里-珀罗干涉型(EFPI)传感器解调的三波长数字相位解调法的解调原理,仿真和实验分析了三波长数字相位解调法的解调误差。仿真分析结果表明,相位偏离正交关系是限制解调的最主要因素,要保证解调误差在15 nm以内,腔长变化应小于在正交腔长处2 μm的范围。采用3个独立的激光光源进行实验,实验结果表明,在正交腔长附近1 μm范围内变化,解调腔长误差小于12 nm,重复性误差小于10 nm,解调具有良好的稳定性。
Abstract:This paper introduces the traditional demodulation method of Fabry-Perot (F-P) sensors, and systematically derives the demodulation principle of three-wavelength digital phase demodulation method using extrinsic Fabry-Perot interferometer (EFPI) sensors. Meanwhile, simulation method has been used to analyze the demodulation error of three-wavelength phase demodulation method. The results indicate that the phase deviation from an orthogonal relationship is the most important influencing factor limiting the demodulation. In order to ensure that demodulation error is less than 15 nm, the cavity length change should be within the range of 2 μm at the orthogonal cavity length. Three independent laser light sources have been used to do the experiment. The results show that when the cavity length changes within 1 μm from orthogonal cavity length, the error of the demodulation cavity length is less than 12 nm, and at the same time the repeatability error of the demodulation is less than 10 nm, which means that demodulation has good stability.
Real-time High Sensitivity Variation of Solution Concentration Monitor Based on Fabry-Perot Interferometer

JIN Qing-li,YAN Li-fen,WANG Zhen-guo,

光子学报 , 2010,
Abstract: A real-time solution concentration monitor based on Fabry-Perot interferometer is designed.The concentration variation measurement is realized by the F-P interferometer and optical fiber to transmit the image to the CCD.The relation between the variation of interference fringes of the F-P interferometer and the fluctuation of solution concentration is analyzed.The monitor system consists of He-Ne laser,optical fiber,planar F-P interferometer,arrayed CCD and PC is set up.Three different glycerin solution are used to verify the system design,and the experiment shows the system can provide a resolution on the order of 10-4 concentration variation.


红外与毫米波学报 , 1991,
Abstract: 提出了用扫描Fabry-Perot干涉仪对光电系统10~500MHz的频率响应进行测试的方法。用信号半值宽度τ_m来估计光电系统的高频截止频率fc,讨论了fc=1/1.7τ_m的理论依据和适用范围。本方法的特点是无需高频光源和高频信号源,即可进行光电系统的高频响应测试。
Page 1 /559
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.