Improving the numerical stability of T-matrix light scattering calculations for extreme particle shapes using the nullfield method with discrete sources

Over the years the T-matrix method based on the nullfield method established itself as a fast and reliable approach for light scattering simulation. Compared to other programs based on discrete dipole approximation or finite different time domain, programs calculating the T-matrix usually are faster. Unlike the Mie theory the underlying nullfield method can also be used for non-spherical particles, but one will observe a limited numerical stability in this case. Using an advanced approach, the nullfield method with discrete sources, we would like to demonstrate how to improve the numerical stability and to get results also for particles with extreme shapes like fibers or discs with high aspect ratios or concavities. In this paper we intentionally keep the mathematical part rather small, instead we focus on more general explanations for users of corresponding computer programs by outlining basic ideas and concepts. (C) 2011 Elsevier Ltd. All rights reserved.