Publications (7) View all
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Article: Multiple scales analysis of chirped Bragg gratings
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ABSTRACT: In this paper, a second-order multiple scales expansion is used to derive coupled-mode equations for a linearly chirped Bragg grating. This eliminates the error in the spectral response introduced by large values of the grating strength when conventional first-order coupled-mode theory is used. The autonomous and nonautonomous formulations of these equations are considered and compared in terms of accuracy and speed of the numerical solution of the resulting two-point boundaryvalue problem for the reflectance of the grating. These solutions are compared with the characteristic matrix solution taken as a reference. By using the fundamental matrix method, the autonomous formulation is found to be as accurate as the characteristic matrix method but faster in terms of computer CPU time.International Journal of Electronics and Communications (AEU). 01/2010; 64:398-402. -
Article: Errata--- correction to --Application of multiple scales analysis and the fundamental matrix method to rugate filters: initial and two-point boundary problem formulations~
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ABSTRACT: Not AvailableJournal of Lightwave Technology 10/2001; 19(9):1385-1385. · 2.78 Impact Factor -
Article: Application of multiple scales analysis and the fundamental matrixmethod to rugate filters: initial-value and two-point boundary problemformulations
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ABSTRACT: In this paper, the filtering problem of apodized rugates is solved by deriving first-order, as well as second-order, coupled-mode equations via the perturbation method of multiple scales. The first-order perturbation equations are the same as those of coupled-mode theory. However, the second-order perturbation expansion is more accurate, and permits the use of larger amplitudes of the periodic index variation of the rugate. The coupled-mode equations are solved numerically by using two different formulations. The first approach is a two-point boundary-value problem formulation, based on the fundamental matrix solution, that is essentially the exact solution for the unapodized rugate. The second approach is an initial-value problem formulation, that uses backward integration of the coupled-mode equations. Comparison with the characteristic matrix method is made for the case of unapodized rugate in terms of speed and accuracy, and it is found that the fundamental matrix solution is the fastest. The accuracy of the multiple scales solution is measured in terms of the amplitude error and the phase error of the filter's spectral response, taking the characteristic matrix solution as a reference for the unapodized rugate. The proposed formulations are utilized to calculate the spectral response of apodized rugatesJournal of Lightwave Technology 01/2001; 18(12):2217-2223. · 2.78 Impact Factor -
Conference Proceeding: A fast algorithm for calculating the reflectance of nonabsorbingmultilayer dielectric films
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ABSTRACT: In this paper, filtering nondesired bands of a polychromatic beam using multilayer dielectric films is described. The stop-bands could be placed anywhere in the spectrum range by carefully choosing the thickness and the refractive index of each layer. The total thickness of the structure, or the number of layers, affects the frequency response of the filter in such a way that increasing the number of coefficients of a digital filter or increasing the number of elements in an antenna array affects the respective responses. From computational point of view, reduction of computational time has been achieved by computing the characteristic matrix just once for similar layers. Illustrative examples are also givenAntennas and Propagation Society International Symposium, 1998. IEEE; 07/1998 -
Dataset: JEWA Circular WG
