Berlin 2005 – scientific programme
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HL: Halbleiterphysik
HL 62: Photonische Kristalle IV
HL 62.5: Talk
Wednesday, March 9, 2005, 11:45–12:00, TU P164
Disorder in metallic photonic crystal slabs — •Dietmar Nau1, Anja Schönhardt1, Harald Giessen1, André Christ2, and Jürgen Kuhl2 — 1Institut für Angewandte Physik, Universität Bonn, Wegelerstraße 8, D-53115 Bonn — 2Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569 Stuttgart
It is well known that the optical properties of gold nanostructures can be tailored by arranging them periodically on top of a dielectric waveguide material [1]. This effect can be explained by the formation of a new quasi-particle, a so-called waveguide-plasmon polariton [2]. In this work we present a detailed study of the influence of disorder in these structures. Samples with a controlled amount and type of disorder are fabricated. We vary the positions of the nanostructures with respect to the original grid. We consider frozen-phonon disorder, where the nanostructures are shifted similar to phonons in a solid, and another model with far-field disorder. The models are characterized in detail by their two-particle correlation functions, and the optical properties of the different structures are determined. We find that the linear optical properties are changed dramatically. The modulation in the extinction due to the polariton formation decreases for increasing disorder. Also, the bandstructure is influenced. Disorder causes the splitting of the bands to decrease due to a reduced spatial overlap of the wavefunctions of plasmon and waveguide mode. Different disorder models influence the specific optical properties in different ways.
[1] S. Linden et al., Phys. Rev. Lett. 86, 4688 (2001) [2] A. Christ et al., Phys. Rev. Lett. 91, 183901 (2003)