Ellipsometric characterization of chiral plasmonic nanostructures

Plasmonic nanostructures exhibiting chiroptical effects attract a great interest and possess a broad spectrum of applications. Their real-life applicability, however, is hindered by both a lack of large-area fabrication procedures as well as a complicated optical response resulting from polarization mixing effects, the latter of which limits the identification of true circular dichroism. In this paper we present a simplified fabrication procedure based on nanosphere lithography combined with glancing angle deposition. The nanostructures are characterized in Linear and Circular Dichroism experiment with the use of Muller-Matrix Spectroscopic Ellipsometry followed by differential matrix decomposition analysis. The experiment shows that these nanostructures are sensitive to both linear and circular polarization and exhibit distinctive plasmonic resonances in both polarization regimes making them promising for multichannel enantioselective biosensing.