Strain profile reconstruction of fiber Bragg grating with gradient using chaos genetic algorithm and modified transfer matrix formulation

• Published in: Optics communications Vol. 281; no. 13; pp. 3476 - 3485
• Main Authors: Zhang, Rongxiang, Zheng, Shijie, Xia, Yanjun
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2008; Elsevier Science
• Subjects: Chaos genetic algorithm; Computers in experimental physics; Data analysis: algorithms and implementation; data management; Exact sciences and technology; Fiber Bragg grating; Fiber optics; Fundamental areas of phenomenology (including applications); General equipment and techniques; Gratings; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Modified transfer matrix; Optical elements, devices, and systems; Optics; Physics; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Sensors, gyros; Spline smooth function; Strain gradients; Strain profile reconstruction; Spline smooth function; Fiber Bragg grating; Strain profile reconstruction; Chaos genetic algorithm; Modified transfer matrix; Strain gradients; Theoretical study; Diffraction gratings; Grating in fiber; Genetic algorithms; Strain sensors; Fiber optic sensors; Bragg gratings; Strains; Spline functions; Transfer matrix method; T matrix; Spatial resolution
• ISSN: 0030-4018; 1873-0310
• DOI: 10.1016/j.optcom.2008.02.051

In this paper, a new heuristic approach based on chaos genetic algorithm and modified transfer matrix method is presented to demodulate the fiber Bragg grating strain sensors. To facilitate accurate calculation of the grating reflected intensity spectrum, the modified transfer matrix approach is applied. The motivation for using the spline smooth function scheme is to provide nice approximation of strain profiles from a scattered data set and overcome the difficulty of calculating the strain gradients in local period function of the modified T-matrix formulation for the piecewise constant strain field assumption. The chaos genetic algorithm is developed to improve the performance of GA and optimize the data of control nodes of the spline smooth function, and more valuably, the reconstructed strain profile is continuous with discretionary spatial resolution. The proposed method is verified through numerical example reconstructions of Bragg grating sensor simulated strain profile cases.