Vortrag im Rahmen der Chemisch Physikalischen Gesellschaft
The scattering of waves is a central process in many physical systems. Its often very complicated nature has negative ramifications for the capability to achieve certain tasks and therefore on applications due to the perceived destruction of information. Prominent examples of these adverse effects include the reduced line of sight on a foggy day, the limited reception of cell phones and degrading image quality in biomedical imaging. The most important piece of the puzzle to counter this is the precise control over incoming waves and the accurate measurement of the scattered waves.
In this thesis, we try to provide important insights into this emerging field of wave control in disordered media. Based on the most important tool in scattering theory – the scattering matrix, that takes care of the bookkeeping in scattering processes – we introduce a new capability for the study of scattering problems, which is not restricted to the investigation of a specific subclass of problems but is applicable to all manners of scattering problems with any type of wave. This novel tool, dubbed the generalized Wigner-Smith (GWS) operator, leverages not only information stored in the scattering matrix, but also the response of the scattering matrix to (small) changes in the system.
