Plasmonic origami: tuning optical properties by periodic folding of a gold nano film

Abstract

Novel plasmonic structures are on the rise, with applications varying from sensing and spectroscopy to solar cells and biological therapies. In this work, we introduce a plasmonic metasurface with a very rich dispersion spectrum, measured both experimentally and numerically. It shows a tunable absorption that depends on the folding angle and periodicity. A detailed numerical analysis identifies the presence of quasi-omnidirectional absorption. This broad directional absorption mode matches a Fabry–Perot resonance of a surface plasmon polariton along an elementary segment of the periodic structure. This geometry induced wide directional absorption is highly promising for a variety of photonic, light harvesting, and sensing applications.