Active wavelength demodulation of Bragg fibre-optic strain sensor using acousto-optic tunable filter

Recently, the research on smart textile has become more and more prevalent. As for the current algorithm in detecting the temperature, the accuracy is not high enough. In order to solve this problem, a new algorithm, weighted wavelength demodulation, is proposed in this paper, which is based on the principle of fiber Bragg grating demodulation system. At last, a comparison of the error produced by the traditional algorithm, Gaussian fitting algorithm and the weighted wavelength demodulation algorithm is made, which shows that the new algorithm is more accurate than the others, even though the sampling points are much less than the others. Meanwhile, the new algorithm also reduces the computation greatly. This wavelength detection algorithm is suitable for embedded systems. The experiment results show that an accuracy of 5pm wavelength demodulation and a resolution of 0.1 o C temperature can be obtained when the sampling frequency of temperature is 1Hz.

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“…Therefore, we can calculate the variable quantity of temperature and strain by detecting B λ Δ [6,7,8,9].…”

Section: Fbg Sensing Principlementioning

confidence: 99%

“…e) Step5: Do the weighted averaging to the data in the windows by formula (8) and the corresponding number of peak sampling points can be gotten more accurately. , 1,2, ,…”

Section: D) Step4mentioning

confidence: 99%

Application of Wavelength Demodulation Algorithm on Calculating Body's Temperature in Smart Textile Based on Fiber Bragg Grating

Song

Miao

Zhang

et al. 2009

2009 2nd International Congress on Image and Signal Processing

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“…The reflective spectrum of sensing FBG can be modeled as a Gaussian distribution [4] of wavelengths with a spectral full width at half-maximum(FWHM) of ∆λ B and a center wavelength of λ B .. And the reflective spectrum of chirp grating can be modeled as rectangle, as shown in Fig.2.…”

Section: Bbsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Many wavelength-detection techniques for fiber Bragg grating sensors have been proposed. These techniques include Matched-filter interrogation technique [3] , Fourier transform technique [4] , tunable filters [5] , interferometric techniques [6] , and so on.In this paper, we propose a novel method of the demodulation of FBG sensing system based on chirp grating and LPG edge filter, in which chirp grating is used as band filter. Compared to other demodulation methods, this adopt non-mechanism designation.…”

mentioning

confidence: 99%

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A novel method for the demodulation of fiber Bragg grating sensing system based on chirp grating

et al. 2004

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In this paper, we propose a novel method of the demodulation of FBG sensing system based on chirp grating and LPG edge filter in which chirp grating is used as band filter. The measurement speed is mainly determined by the response time of the photo-detector and the convert time of AD chips. So, it can highly improve the stability and scan speed of the sensing system. In the experiment system, we use fiber Bragg grating and adjust its bandwidth to get a chirp grating.. The center wavelength of chirp grating is 1551.60nm, and the pass-band wavelength is 7nm.The LPG is written on a standard single mode fiber with microlens array. The grating has a period of 440µm and a length of 3 cm. The center wavelength of LPG is 1558nm, and the falling edge of LPG is from 1540nm to 1555nm. We investigate light power by using a monitor magnify circuit, while the reflected wavelength of FBG by using optical spectrum analyzer. This system has high linear output and the linear fitting is 0.9918. The windage is due to the non-perfect square spectral profile of the reference chirp fiber grating. Keywords: FBG demodulation, FBG sensor, high-speed demodulation 1.IntroductionRecently, fiber Bragg Gratings(FBGs) are attracting considerable interest for applications in sensing elements such as strain, temperature and pressure [1][2] for their intrinsic nature and inherent wavelength-encoded operation. Thus, it is important to develop a simple system to measure the spectrum. Many wavelength-detection techniques for fiber Bragg grating sensors have been proposed. These techniques include Matched-filter interrogation technique [3] , Fourier transform technique [4] , tunable filters [5] , interferometric techniques [6] , and so on.In this paper, we propose a novel method of the demodulation of FBG sensing system based on chirp grating and LPG edge filter, in which chirp grating is used as band filter. Compared to other demodulation methods, this adopt non-mechanism designation. The measurement speed is mainly determined by the response time of the photo-detector and the convert time of AD chips. So, it can highly improve the stability and scan speed of the sensing system.

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Active Wavelength Measurement Systems Based on Quantum Well Electroabsorption Devices

Coroy

Measures

1997

Applications of Photonic Technology 2

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Active wavelength demodulation of Bragg fibre-optic strain sensor using acousto-optic tunable filter

Cited by 14 publications

References 4 publications

Application of Wavelength Demodulation Algorithm on Calculating Body's Temperature in Smart Textile Based on Fiber Bragg Grating

Application of Wavelength Demodulation Algorithm on Calculating Body's Temperature in Smart Textile Based on Fiber Bragg Grating

A novel method for the demodulation of fiber Bragg grating sensing system based on chirp grating

Active Wavelength Measurement Systems Based on Quantum Well Electroabsorption Devices

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