title: From Dark to Bright: First-Order Perturbation Theory with Analytical Mode Normalization for Plasmonic Nanoantenna Arrays Applied to Refractive Index Sensing.
abstract: We present a first-order perturbation theory to calculate the frequency shift and linewidth change of photonic resonances in one- and two-dimensional periodic structures under modifications of the surrounding refractive index. Our method is based on the resonant state expansion, for which we extend the analytical mode normalization to periodic structures. We apply this theory to calculate the sensitivity of bright dipolar and much darker quadrupolar plasmonic modes by determining the maximum shift and optimal sensing volume.
authors.affiliation: 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Weiss
authors.affiliation: 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Mesch
authors.affiliation: 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Schäferling
authors.affiliation: 4th Physics Institute and Research Center SCoPE, University of Stuttgart, Pfaffenwaldring 57, D-70550 Stuttgart, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Giessen
authors.affiliation: Cardiff University, School of Physics and Astronomy, The Parade, CF24 3AA Cardiff, United Kingdom.
authors.forename: W
authors.initials: W
authors.lastname: Langbein
authors.affiliation: Cardiff University, School of Physics and Astronomy, The Parade, CF24 3AA Cardiff, United Kingdom.
authors.forename: E A
authors.initials: EA
authors.lastname: Muljarov