Piatkový seminár fyziky - Vladimír Kuzmiak (6.11.2015)

v piatok 6.11.2015 o 14:00 hod. v miestnosti F2/272

01. 11. 2015 21.36 hod.
Od: Peter Markoš

Prednášajúci: Vladimír Kuzmiak (Ústav fotoniky elektroniky AV ČR)

Názov prednášky: Transmission properties of surface plasmon-polaritons in nanostuctured metallic surfaces.

Termín: 6.11.2015, 14:00 hod., F2/272


The metallic nanostructures derive their unique properties from their ability to support collective electron excitations known as surface plasmon-polaritons (SSPs). Surface polaritons are quasi-two-dimensional electromagnetic waves that propagate along a dielectric-metal interface with amplitude that decay exponentially with increasing distance into both neighboring media. The possibility to confine the light into subwavelength volumes, which stems from the latter feature has profound effect on the efficiency of many optical processes and makes surface plasmon-polaritons very sensitive to surface properties. We have recently explored naostructured two-dimensional surfaces which may provide a platform for a realistic optical analog of one-way electron devices. We have shown that a square array of scatterers deposited on a metal surface in a triangular mesh to which a diffractive structure is added to the left side of the array reveals asymmetric transmission of surface plasmon polaritons [1]. The mechanism for this property is related to the higher Bragg modes that are excited due to the diffractive structure. Recently, we investigated theoretically the propagation of a surface plasmon polariton propagating along the metal/air interface where metallic part consists of two metallic sections with a periodically modulated interface between them [2]. We find that such a structure exhibits asymmetric transmittance for a SPP incident on it from opposite sides. This asymmetric transmission originates from diffraction which occurs at the in-plane grating between two metals which implies the suppression of the 0-order SPP Bragg beam and the diffraction efficiencies of the +1 and -1 Bragg beams can be controlled by varying the lattice constant of the grating and/or the angle of incidence. A major part of our presentation is devoted to our investigation of the propagation of a surface plasmon polariton on a metallic grating consisting of N equally spaced rectangular grooves, each with the same width but with varying depths. We find that the transmissivity of the surface plasmon-polariton, and the power radiated into the vacuum, as functions of its frequency consist of N equally spaced dips and peaks, respectively, that have the form of a Wannier-Stark ladder [3].

[1] V. Kuzmiak and A. A. Maradudin, Phys. Rev A 86, 043805 (2012).
[2] V. Kuzmiak and A. A. Maradudin, “Asymmetric transmission of surface plamon polaritons on planar gratings“, to appear in Phys. Rev. A.
[3] V. Kuzmiak, A. A. Maradudin, and E. R. Méndez: “Surface plasmon polariton Wannier- Stark-ladder”, Opt. Lett. 39, 1613 (2014).

Stránka seminára