  We discuss the possibility of realizing utlrabroadband omnidirectional
absorbers and angularly selective coherent thermal emitters based on properly
patterned plasmonic metastructures. Instead of relying on resonant
concentration effects that inherently limit the bandwidth, we base our design
on the combination of two inherently nonresonant effects: plasmonic Brewster
funneling and adiabatic plasmonic focusing. With this approach, we demonstrate
compact, broadband absorption and emission spanning terahertz, infrared and
optical frequencies, ideal for various energy and defense applications.
