Extending the applicability of the T-matrix method to light scattering by flat particles on a substrate via truncation of Sommerfeld integrals

• Main Authors: Egel, Amos, Eremin, Yuri, Wriedt, Thomas, Theobald, Dominik, Lemmer, Uli, Gomard, Guillaume
• Format: Journal Article
• Language: English
• Published: 23-08-2017
• Subjects: Physics - Optics
• DOI: 10.48550/arxiv.1708.05557

Journal of Quantitative Spectroscopy and Radiative Transfer 202C
(2017) pp. 279-285 The simulation of light scattering by particles on a substrate with the
$T$-matrix method relies on the expansion of the scattered field in spherical
waves, followed by a plane wave expansion to allow the evaluation of the
reflection from the substrate. In practice, the plane wave expansion (i.e., the
Sommerfeld integrals) needs to be truncated at a maximal in-plane wavenumber
$\kappa_\mathrm{max}$. An appropriate selection of $\kappa_\mathrm{max}$ is
essential: counter-intuitively, the overall accuracy can degrade significantly
if the integrals are truncated with a too large value. In this paper, we
propose an empirical formula for the selection of $\kappa_\mathrm{max}$ and
discuss its application using a number of example simulations with dielectric
and metallic oblate spheroids on dielectric and metallic substrates. The
computed differential scattering cross sections are compared to results
obtained from the discrete-sources method.