3-DIMENSIONAL BEAM-PROPAGATION ANALYSIS OF NONLINEAR-OPTICAL FIBERS AND OPTICAL LOGIC GATES

A three-dimensional (3-D) beam propagation method is described for the analysis of nonlinear optical fibers, where the finite element and fi nite difference methods are, respectively, utilized for discretizing t he fiber cross section and the propagation direction, For efficient ev aluation of wide-angle beam propagation, Pade approximation is applied to the differential operator along the propagation direction, In orde r to improve the efficiency and accuracy of solutions, isoparametric e lements and numerical integration formulae derived by Hammer et at are introduced. The propagation characteristics of nonlinear optical fibe rs with linear core and nonlinear cladding are analyzed, and unique fe atures of nonlinear guided-wave propagation are investigated, Furtherm ore, all-optical logic gates with practical, 3-D geometry consisting o f optical fibers and a nonlinear film are proposed, and their operatio ns of Boolean arithmetric are demonstrated.