Stabilising the Du Fort Frankel beam propagation scheme for modelling lossy structures

The Du Fort Frankel beam propagation method is an explicit three level scheme that is ideally suited to parallel computing. In the case of media without loss or gain, the scheme is conditionally stable allowing relatively large propagation steps, however in the presence of loss or gain it is always unstable. A stabilised Du Fort Frankel scheme is presented that extends the scope of this powerful method to cover these practically important scenarios.