title: Analytic Optimization of Near-Field Optical Chirality Enhancement.
abstract: We present an analytic derivation for the enhancement of local optical chirality in the near field of plasmonic nanostructures by tuning the far-field polarization of external light. We illustrate the results by means of simulations with an achiral and a chiral nanostructure assembly and demonstrate that local optical chirality is significantly enhanced with respect to circular polarization in free space. The optimal external far-field polarizations are different from both circular and linear. Symmetry properties of the nanostructure can be exploited to determine whether the optimal far-field polarization is circular. Furthermore, the optimal far-field polarization depends on the frequency, which results in complex-shaped laser pulses for broadband optimization.
authors.affiliation: Institut für Physikalische und Theoretische Chemie, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Kramer
authors.affiliation: 4th Physics Institute, Research Center SCoPE, and Research Center SimTech, University of Stuttgart , Pfaffenwaldring 57, 70550 Stuttgart, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Schäferling
authors.affiliation: 4th Physics Institute, Research Center SCoPE, and Research Center SimTech, University of Stuttgart , Pfaffenwaldring 57, 70550 Stuttgart, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Weiss
authors.affiliation: 4th Physics Institute, Research Center SCoPE, and Research Center SimTech, University of Stuttgart , Pfaffenwaldring 57, 70550 Stuttgart, Germany.
authors.forename: Harald
authors.initials: H
authors.lastname: Giessen
authors.affiliation: Institut für Physikalische und Theoretische Chemie, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Brixner
keywords: analytic optimization; chiroptical spectroscopy; femtosecond polarization pulse shaping; near-field response; optical chirality; plasmonics