Physical Colloquium Guest Lecture

Nanophotonic simulations using the boundary element method

Prof. Dr. Ulrich Hohenester, Karl-Franzens-Universität Graz

Computational Maxwell solvers based on the boundary element method (BEM) enable fast and accurate simulations of sufficiently small scatterers. Over the last few years, we have developed our own BEM Maxwell solver termed nanobem, and have implemented the computation of T-matrices for scatterers with arbitrary geometries [1].

The combination of BEM and T-matrices has allowed us to develop two add-ons to the nanobem toolbox dealing with optical tweezers and optical interference microscopies, which have been used for life science applications. In this talk I will first present our simulation approach for optofluidic force induction, a novel nanoparticle characterization scheme based on optical and fluidic forces [2]. I will then discuss interference scattering microscopy (iSCAT), allowing for label-free localization of proteins and other nanoparticles, and how the localization precision can be improved using the concept of (quantum) Fisher information [3,4].

References
[1]           N. Asadova et al., JQSRT 333, 109310 (2025).External link
[2]           M. Šimić et al., Nano Letters 25, 8805 (2025).External link
[3]           F. Hitzelhammer et al., ACS Photonics 11, 2745 (2024)External link.
[4]           U. Hohenester et al., Nanophotonics 14, 4351 (2025).External link