How HPC helps exploring electromagnetic near fields
Prof. Dr. Jens Förstner
Theoretical Electrical Engineering, Paderborn University
The classical electromagnetic theory by Maxwell has an astonishingly broad validity ranging from static electric fields to radio signals, microwaves, Wi-Fi, mobile communication, thermal radiation, light from the infrared to the visible to the ultraviolet spectrum, X-rays, and high energy cosmic radiation. The exact same equations describe the dynamics of electromagnetic fields of all frequencies. However, matter behaves differently depending on the frequency and can be arranged differently on different spatial scales. Especially on the mesoscopic electromagnetic scale, i.e. if objects are considered which are of the scale of the electromagnetic wavelength, near-field effects like evanescent fields become important, the field is no longer a simple plane wave, and common approximations and analytical approaches fail. Then, large scale numerical simulations are required to analyze the electromagnetic dynamics. We have a look at several systems considered in the Theoretical Electrical Engineering group at Paderborn University ranging from optical antennas, biological frequency filters, interplanetary dust particles, and metamaterials for frequency conversion.