Traditionally, one can calculate the update coefficients of the finite-difference time-domain algorithm at material interfaces by averaging the material properties of both sides, which leads to numerical inaccuracies of the reflection depending on the grid resolution. We propose a novel method to calculate the update coefficients such that the algorithm exactly fulfills the boundary conditions at a frequency of optimization, which allows a significant increase in grid spacing while limiting the numerical error. Using the proposed method, we reduced the computational expenses for the full-wave simulation of vertical-cavity surface-emitting lasers such that large structures can be treated without the need to exploit rotational symmetry. The method is demonstrated with the help of several examples.
© 2003 Optical Society of America
(000.3860) General : Mathematical methods in physics
(000.4430) General : Numerical approximation and analysis
(030.4070) Coherence and statistical optics : Modes
(250.7260) Optoelectronics : Vertical cavity surface emitting lasers
Andreas Christ, Niels Kuster, Matthias Streiff, Andreas Witzig, and Wolfgang Fichtner, "Correction of the numerical reflection coefficient of the finite-difference time-domain method for efficient simulation of vertical-cavity surface-emitting lasers," J. Opt. Soc. Am. B 20, 1401-1408 (2003)