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In the frame of a large-stroke optical fiber delay line implementation, using the ability of silica fibers to induce large and variable group delay when they are stretched, we intend to express theoretically the evolution of second-order chromatic dispersion versus fiber stretching. Both an experimental analysis and a numerical analysis are presented in this paper. The main result consists of the observation of a linear variation of the second-order chromatic dispersion versus a 0 to 32-cm group delay variation. The numerical simulation exhibits a discrepancy of 10% with respect to the experimental results.

A cylindrical form of the finite difference beam propagation method (FD-BPM) is, for the first time, proposed to make easier the analysis of optical waveguide configurations for which the index profiles have a revolution symmetry and maintain an azimuthal symmetry of the field distribution. For these configurations the new 2D cylindrical FD-BPM requires a computation time shorter than that of the classical 3D Cartesian FD-BPM. Solutions are given to remove numerical difficulties occuring on the revolution axis. The proposed method is first applied, in association with the Wijnands's method, to solving the modes of two fibers with complicated index profile. It is also applied to studying the progressive transition between two different monomode fibers.