A Wide-Angle Beam Propagation Method Using Denman–Beavers Iterative Scheme

A new algorithm for the wide-angle beam propagation method (BPM) is proposed, where the propagation propagator in the Helmholtz equation is approximated by the Denman-Beavers iterative scheme. By rotating the propagator into the complex plane, the generally concerned problem, incorrect evolution of the evanescent waves, in the conventional BPM is well solved, greatly improving the computational stability and convergent behaviors. Numerical results from several typical tests show that the present approach has reasonable efficiency and high accuracy with the convergence rate faster than the widely used Padé-based BPM.