Abstract

The beam-propagation method (BPM) has successfully been used to analyze various optical waveguides. Since the conventional paraxial approximation restricts the application, several techniques have been proposed to treat wide-angle beam propagation [1]-[7]. Of them a so-called multistep method [4] in which the Padé approximant operator is factored into a series of simpler Padé (1,1) operators has an advantage that it allows paraxiallike solution techniques, such as the Thomas algorithm. The previous formulation is, however, based on the Crank-Nicholson (CN) scheme with a truncation error of O(Δϰ)² in the transverse direction.

© 1996 Optical Society of America