Optical Brewster Metasurfaces Exhibiting Ultrabroadband Reflectionless Absorption and Extreme Angular Asymmetry

Ultrabroadband reflectionless absorption of light is in great demand for many applications. This study proposes a type of nonresonant, impedance-matched optical metasurface that exhibits ultrabroadband reflectionless absorption, based on the anomalous Brewster effect. Extremely asymmetric behavior---a transition from perfect transparency to perfect absorption---appears when the sign of the angle of incidence changes, due to the coexistence of the traditional and anomalous Brewster effects. Such high-efficiency metasurfaces may find application in optoelectronic and thermal devices such as photovoltaics, photodetectors, and thermal emitters.