title: Chiroptical effects in planar achiral plasmonic oriented nanohole arrays.
abstract: Chiroptical effects are routinely observed in three dimensional objects lacking mirror symmetry or quasi-two-dimensional thin films lacking in-plane mirror symmetry. Here we show that symmetric plasmonic planar arrays of circular nanoholes produced strong chiroptical responses at visible wavelengths on tilting them with respect to the incident light beam due to the collective asymmetric nature of their surface plasmon excitations. This extrinsic chiroptical effect can be stronger than the local chiroptical response in arrays of intrinsically chiral nanoholes and may be useful for chiral sensing and negative refraction.
authors.affiliation: Department of Chemical Physics, School of Chemistry, Raymond and Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
authors.forename: Ben M
authors.initials: BM
authors.lastname: Maoz
authors.forename: Assaf Ben
authors.initials: AB
authors.lastname: Moshe
authors.forename: Daniel
authors.initials: D
authors.lastname: Vestler
authors.forename: Omri
authors.initials: O
authors.lastname: Bar-Elli
authors.forename: Gil
authors.initials: G
authors.lastname: Markovich