GDFIDL - A FINITE-DIFFERENCE PROGRAM FOR ARBITRARILY SMALL PERTURBATIONS IN RECTANGULAR GEOMETRIES

A FD-program for calculating the resonant fields in a perturbed chain of rectangular cavities is presented. The unperturbed cavity chain can be discretized exactly by standard FD-programs that operate on regula r grids, Discretizing a perturbed chain exactly with such a grid would lead to a computation time inversely proportional to the perturbation . GdfidL does not represent the grid as a matrix but as a linked list. This allows discretizing arbitrarily small perturbations of a certain class without increasing the time for the solution. As a nice side-ef fect, only interesting volumes are discretized, reducing the computati on time further.