Highly-directive systems inspired by physical bounds on scattering processes

The identification of physical bounds of performance is central to the understanding of light-matter interactions and the design of optimal devices that reach those theoretical limits. Here, we extend our previous work to derive physical bounds of performance for time-harmonic scattering processes, including total scattering, total absorption, bistatic scattering and minimal scattering sensors, for arbitrary far-field illumination of a system in the presence of a material interface. The derived upper bounds emphasize a weighted function of the scattering directivity as the main limiting factor in the theoretically achievable performance for all aforementioned scattering processes. Therefore, our analysis remarks the potential benefits of using highly-directive systems in multiple configurations.