title: Near-field circular polarization probed by chiral polyfluorene.
abstract: We demonstrate that a high degree of circular polarization can be delivered to the near field (NF) of an aperture at the apex of hollow-pyramid probes for scanning optical microscopy. This result is achieved by analyzing the dichroic properties of an annealed thin polymer film containing a chiral polyfluorene derivative, placed in close proximity to the optical probe. We also prove that the degree of circular polarization in the probe NF does not depend in a significant way on the shape of the aperture, at variance with the far-field behavior. These results demonstrate the feasibility of nano-optics applications exploiting circularly polarized NFs.
authors.affiliation: Dipartimento di Fisica-CNISM, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Savoini
authors.forename: P
authors.initials: P
authors.lastname: Biagioni
authors.forename: G
authors.initials: G
authors.lastname: Lakhwani
authors.forename: S C J
authors.initials: SC
authors.lastname: Meskers
authors.forename: L
authors.initials: L
authors.lastname: Duò
authors.forename: M
authors.initials: M
authors.lastname: Finazzi