title: A compact source condition for modelling focused fields using the pseudospectral time-domain method.
abstract: The pseudospectral time-domain (PSTD) method greatly extends the physical volume of biological tissue in which light scattering can be calculated, relative to the finite-difference time-domain (FDTD) method. We have developed an analogue of the total-field scattered-field source condition, as employed in FDTD, for introducing focussed illuminations into PSTD simulations. This new source condition requires knowledge of the incident field, and applies update equations, at a single plane in the PSTD grid. Numerical artifacts, usually associated with compact PSTD source conditions, are minimized by using a staggered grid. This source condition's similarity with that used by the FDTD suggests a way in which existing FDTD codes can be easily adapted to PSTD codes.
authors.forename: Peter R T
authors.initials: PR
authors.lastname: Munro
authors.forename: Daniel
authors.initials: D
authors.lastname: Engelke
authors.forename: David D
authors.initials: DD
authors.lastname: Sampson