DocumentCode :
2727342
Title :
Accurate optical fiber refractive index reconstruction from near field
Author :
Boucouvalas, A.C. ; Thraskias, C.A.
Author_Institution :
Dept. of Telecommun. Sci. & Technol., Univ. of Peloponnese, Tripoli
fYear :
2008
fDate :
25-25 July 2008
Firstpage :
500
Lastpage :
505
Abstract :
An efficient algorithm is proposed for calculating directly and accurately the refractive index profile of cylindrical waveguides from knowledge of the mode near field. This inverse problem is solved using transmission line techniques. For the solution of this problem it is required the mode propagation constant beta in the waveguide. In this work we present the theory for estimating the mode propagation constant beta accurately. The calculation of the propagation constant beta is vital for the refractive index reconstruction and we show that it implies error minimization in the refractive index synthesis from near field. From Maxwellpsilas equations, we derive an equivalent transmission-line circuit for a cylindrical dielectric waveguide. Based on an analytical method, that computes the error in the reconstructed refractive index due to inaccuracy in beta. Subsequently we work out the exact value of the propagation constant beta. The proposed analytical method computes the refractive index error directly without the need for curve fitting or numerical differentiation. We demonstrate this algorithm with example reconstructions for step, triangular and parabolic optical fiber refractive index profiles. This technique is exact, fast and rapidly convergent.
Keywords :
Maxwell equations; curve fitting; equivalent circuits; minimisation; optical fibres; refractive index; Maxwellpsilas equations; curve fitting; cylindrical dielectric waveguide; equivalent circuit; error minimization; mode propagation constant; numerical differentiation; optical fiber; refractive index reconstruction; transmission line; Circuit synthesis; Estimation theory; Inverse problems; Minimization; Optical fibers; Optical waveguide theory; Optical waveguides; Propagation constant; Refractive index; Transmission line theory;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Communication Systems, Networks and Digital Signal Processing, 2008. CNSDSP 2008. 6th International Symposium on
Conference_Location :
Graz
Print_ISBN :
978-1-4244-1875-6
Electronic_ISBN :
978-1-4244-1876-3
Type :
conf
DOI :
10.1109/CSNDSP.2008.4610756
Filename :
4610756
Link To Document :
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