Time-domain methods developed for analyzing electromagnetic wave interactions on complex optical, photonic, and microwave systems have several advantages over their frequency-domain counterparts: (i) They allow for real-time observation of physical processes. (ii) They can accurately account for strong nonlinearities in material properties. (iii) They provide broadband results with a single execution of the solver. However, formulating and implementing efficient, accurate, and stable time-domain solvers is a challenging task because transient wave interactions on electrically large and complex systems involve dispersive relations that have to be modeled using temporal convolutions as well as highly resonant and only-slowly decaying processes. In this presentation, I will talk about two recently developed time-domain electromagnetic solvers that address these challenges. First method is a time-domain discontinuous Galerkin scheme, which uses FFT-accelerated boundary integrals to efficiently and accurately truncate unbounded physical domains into bounded computation domains. Second method is a time-domain volume integral equation solver specifically designed for analyzing wave interactions on structures with high refractive index. I will present several numerical results, which demonstrate that both methods indeed provide accurate and stable results even in the presence of highly resonant processes.
Hakan Bagci is an Assistant Professor in the Division of Computer, Electric al, and Mathematical Sciences and Engineering. Previously, from 2007 to 2009, he worked as a Research Fellow at the Radiation Laboratory, University of Michigan, Ann Arbor, US. He earned his master’s and doctoral degrees in Electrical and Computer Engineering from the University of Illinois, Urbana-Champaign, USA, in 2003 and 2007, respectively. He received his bachelor’s degree in Electrical and Electronics Engineering from the Bilkent University, Ankara, Turkey in 2001. His research interests are in the field of theoretical and applied computational electromagnetics. He focuses on developing acceleration engines, preconditioning techniques, and hybridization methods, which render time and frequency domain integral equation solvers applicable to the analysis of electrically large and multi-scale real-world problems. Hakan Bagci is the recipient of the 2008 International Union of Radio Scientists (URSI) Young Scientist Award and the 2004–2005 Interdisciplinary Graduate Fellowship from the Computational Science and Engineering Department at the University of Illinois, Urbana-Champaign. His paper titled “Fast and rigorous analysis of EMC/EMI phenomena on electrically large and complex structures loaded with coaxial cables” was one of the three finalists (with honorable mention) for the 2008 Richard B. Schulz Best Transactions Paper Award given by the IEEE Electromagnetic Compatibility Society. He authored and co-authored five finalist papers in the student paper competitions at the 2005, 2008, and 2010 IEEE Antennas and Propagation Society International Symposiums and 2013 Applied Computational Electromagnetics Society Conference.