A novel fiber Bragg grating sensor interrogation system utilizing a tunable Fabry-Perot filter

LI Ying; ZHANG Shu-lian

To improve the performance of FBG interrogation system,a novel fiber Bragg grating sensor interrogation system based on a tunable fiber Fabry-Perot (FFP) filter was demonstrated.Firstly,a reference fiber Bragg grating (FBG) was used as a wavelength reference element.By measuring the wavelength difference between reference FBG and sensor FBG,the drift of tunable FFP filter's cavity length was compensated.Secondly,a quadratic fit function wa s made with software based on experiment results.This function showed a good fit to the relationship between the displacement of PZT and control voltage.It was used to calculate the wavelength of the sensing FBG.In experiment,a strain of 0~1800 με was applied to the sensing FBG and the maximum nonlinearity deviat ion of measured wavelength was 0.5%.Experiment results show that the measured er ror caused by the drift of FFP filter's cavity length and PZT's nonlinearity is greatly reduced and a higher accuracy is obtained.

Corresponding author: ZHANG Shu-lian, zsldp@itsinghua.edu.cn

1. State Key Laboratory of Precision Measurement Technology and Instruments, Tsinghua University, Beijing 100084, China

Received Date: 2004-05-08

Accepted Date: 2004-11-15

Available Online: 2005-05-25

Abstract: To improve the performance of FBG interrogation system,a novel fiber Bragg grating sensor interrogation system based on a tunable fiber Fabry-Perot (FFP) filter was demonstrated.Firstly,a reference fiber Bragg grating (FBG) was used as a wavelength reference element.By measuring the wavelength difference between reference FBG and sensor FBG,the drift of tunable FFP filter's cavity length was compensated.Secondly,a quadratic fit function wa s made with software based on experiment results.This function showed a good fit to the relationship between the displacement of PZT and control voltage.It was used to calculate the wavelength of the sensing FBG.In experiment,a strain of 0~1800 με was applied to the sensing FBG and the maximum nonlinearity deviat ion of measured wavelength was 0.5%.Experiment results show that the measured er ror caused by the drift of FFP filter's cavity length and PZT's nonlinearity is greatly reduced and a higher accuracy is obtained.

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Reference (8)

[1]	KERSEY A D,BERKOFF T A,MOREY W W.Multiplexed fiberBragg grating strain sensor system with a fiber Fabry-Perot wavelength filter [J].Opt Lett,1993,18(16):1370～1372.
[2]	KERSEY A D,BERKOFF T A,MOREY W W.Fiber optic Bragg grating sensor with drift-compensated high resolution interferometric wavelength shift detection [J].Opt Lett,1993,18(1):72～74.
[3]	TODD M D,JOHNSON G A,ALTHOUSE B L.A novel Bragg grating sensor interrogation system utilizing a scanning filter,a Mach-Zehnder interferometer and a 3×3 coupler [J].Measurement Science and Technology,2001,12(7):771～777.
[4]	RYU C Y,HONG C S.Development of fiber Bragg grating sensor system using wavelength-swept fiber laser [J].Smart Materials and Structures,2002,11(3):468～473.
[5]	DAVIS M A,KERSEY A D.Matched-filter interrogation technique for fiber Bragg grating arrays [J].Electron Lett,1995,31(10):822～823.
[6]	HUANG Y L,LI J,KAI G Y et al.Temperature compensation package for fiber Bragg gratings [J].Microwave and Optical Technology Letters,2003,39(1):70～72.
[7]	SONG M H,LEE S B,CHOI S S et al.Simultaneous measurement of temperature and strain using two fiber Bragg gratings embedded in a glass tube [J].Opt Fiber Technol,1997,3(2):194～196.
[8]	NING Y N,MELDRUM A,SHI W J et al.Bragg grating sensing instrument using a tunable Fabry-Perot filter to detect wavelength variations [J].Measurement Science and Technology,1998,9(4):599～606.

A novel fiber Bragg grating sensor interrogation system utilizing a tunable Fabry-Perot filter

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References

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