Multiplexing technique using amplitude-modulated chirped fibre Bragg gratings with applications in two-parameter sensing

A multiplexing technique using amplitude-modulated chirped fibre Bragg gratings (AMCFBGs) is presented. This technique realises the multiplexing of spectrally overlapped AMCFBGs with identical centre Bragg wavelength and bandwidth. Since it is fully compatible with the wavelength division multiplexing scheme, the number of gratings that can be multiplexed can be increased by several times. The discrete wavelet transform is used to demodulate such multiplexed signal. A wavelet denoising technique is applied to the multiplexed signal in conjunction with the demodulation. Strain measurements are performed to experimentally demonstrate the feasibility of this multiplexing technique. The absolute error and crosstalk are measured. An application to simultaneous two-parameter sensing is also demonstrated.

[1]  N. Djilali,et al.  In-fibre Bragg grating sensors for distributed temperature measurement in a polymer electrolyte membrane fuel cell , 2009 .

[2]  R. Measures.  Structural Monitoring with Fibre Optic Technology , 2001 .

[3]  Il-Bum Kwon,et al.  Intensity-modulated multiplexing of fiber Bragg grating sensors , 2005 .

[4]  Francis T. S. Yu,et al.  Fiber Optic Sensors , 2002 .

[5]  Yicheng Lai,et al.  Distributed temperature sensing using a chirped fibre Bragg grating , 2004 .

[6]  Ian Bennion,et al.  Chirped fibre Bragg grating optical wear sensor , 2004 .

[7]  J. Macalpine,et al.  A novel wavelength detection technique for fiber Bragg grating sensors , 2002, IEEE Photonics Technology Letters.

[8]  Gang-Ding Peng,et al.  Multiplexed fibre Fizeau interferometer and fibre Bragg grating sensor system for simultaneous measurement of quasi-static strain and temperature using discrete wavelet transform , 2006 .

[9]  Stephen F Collins,et al.  Determination of the position of a localized heat source within a chirped fibre Bragg grating using a Fourier transform technique , 2006 .

[10]  J. Dakin,et al.  Distributed grating sensors using low-coherence reflectometry , 1997 .

[11]  R. Kashyap.  Fiber Bragg Gratings , 1999 .

[12]  Kazuo Hotate,et al.  A multiplexing technique for fibre Bragg grating sensors with the same reflection wavelength by the synthesis of optical coherence function , 2004 .

[13]  Raymond M. Measures,et al.  Fiber optic intra-grating distributed strain sensor , 1994, Optics & Photonics.

[14]  Y. Rao,et al.  Fiber-optic Fabry-Perot sensors based on a combination of spatial-frequency division multiplexing and wavelength division multiplexing formed by chirped fiber Bragg grating pairs. , 2006, Applied optics.

[15]  Nobuo Takeda,et al.  Application of chirped fiber Bragg grating sensors for identification of crack locations in composites , 2004 .

[16]  John P. Dakin,et al.  Modeling and performance analysis of a fiber Bragg grating interrogation system using an acousto-optic tunable filter , 1996 .

[17]  Wei Jin,et al.  Improving the performance of a FBG sensor network using a genetic algorithm , 2003 .

[18]  Gang-Ding Peng,et al.  Simultaneous detection of eight spectrally overlapping carrier modulated fibre Bragg gratings , 2006 .

[19]  P. Childs,et al.  An FBG sensing system utilizing both WDM and a novel harmonic division scheme , 2005, Journal of Lightwave Technology.