Showing papers by "Franz R. Aussenegg published in 2008"
TL;DR: In this paper, the principle and methodology of leakage radiation microscopy (LRM) applied to surface plasmon polaritons (SPPs) is reviewed. And the authors show that LRM is a versatile optical far-field method allowing direct quantitative imaging and analysis of SPP propagation on thin metal films.
Abstract: We review the principle and methodology of leakage radiation microscopy (LRM) applied to surface plasmon polaritons (SPPs). Therefore we first analyze in detail the electromagnetic theory of leaky SPP waves. We show that LRM is a versatile optical far-field method allowing direct quantitative imaging and analysis of SPP propagation on thin metal films. We illustrate the LRM potentiality by analyzing the propagation of SPP waves interacting with several two-dimensional plasmonic devices realized and studied in the recent years.
271 citations
TL;DR: In this paper, an organic LED that acts as an electrically driven source of surface plasmons is reported, which has potential applications in integrated organic photonics and sensing and has been shown to generate a freely propagating beam of surfaceplasmons.
Abstract: An organic LED that acts as an electrically driven source of surface plasmons is reported. The device generates a freely propagating beam of surface plasmons and has potential applications in integrated organic photonics and sensing.
192 citations
TL;DR: This paper reports on the observation of multipolar surface plasmon excitation in lithographically designed gold nanotriangles, investigated by means of far-field extinction microspectroscopy in the wavelength range of 400-1000 nm and shows that the lowest three multipolar excitations are clearly resolved in the visible and near infrared range.
Abstract: In this paper, we report on the observation of multipolar surface plasmon excitation in lithographically designed gold nanotriangles, investigated by means of far-field extinction microspectroscopy in the wavelength range of 400-1000 nm. Several bands are observed in the visible and near infrared regions when increasing the side length of the triangles. The assignment of these peaks to successive in-plane multipolar plasmon modes is supported by calculations using the discrete dipole approximation method. We show that the lowest three multipolar excitations are clearly resolved in the visible and near infrared range. These new spectral features could be very promising in nanooptics or for chemosensing and biosensing applications.
86 citations
TL;DR: The results highlight the potential of hybrid dielectric/metal waveguides for integrating surface plasmon based photonic circuitry or sensing elements into conventional optical devices.
Abstract: We study dielectric/metal thin film multilayers designed for the coupling of dielectric waveguide modes and surface plasmons. The coupling as identified in calculated dispersion relations for extended multilayers is confirmed by measured angle-resolved reflectance data. By lateral structuring of the multilayers the mutual coupling of dielectric and plasmonic modes is directly observed by fluorescence based microscopy. For a light wavelength of 514nm we find a coupling length of 15microm. Our results highlight the potential of hybrid dielectric/metal waveguides for integrating surface plasmon based photonic circuitry or sensing elements into conventional optical devices.
60 citations
TL;DR: In this article, a microcavity OLED with thin film metal electrodes was designed to directly probe a surface plasmons (SP) mode by leaky wave extraction with a high refractive index glass prism coupler.
Abstract: Besides directly emitting light, electroluminescence in organic light emitting diodes (OLEDs) can excite surface plasmons (SPs) on the metal electrodes of the device. By designing a microcavity OLED with thin film metal electrodes, we can directly probe a SP mode by leaky wave extraction with a high refractive index glass prism coupler. Additional angle and polarization resolved reflection measurements on the OLED multilayer structure together with transfer matrix calculations allow us to unequivocally characterize the electroluminescent-driven SP mode.
45 citations
TL;DR: In this article, the role of damping for surface-plasmon pulse propagation and refraction was discussed by analyzing calculated dispersion relations of a metal-dielectric interface.
Abstract: We discuss the role of damping for surface-plasmon pulse propagation and refraction by analyzing calculated dispersion relations of a metal-dielectric interface. Results for a lossless Drude metal are compared to those for a lossy Drude metal and the application relevant materials gold and silver. We find that the imaginary part of the surface-plasmon wave vector rather than the surface-plasmon group velocity defines if normal or negative refraction takes place at lateral boundaries. As a consequence, the group velocity can be opposite to the energy flow. This is not in contradiction to causality, as due to large damping in regions of negative group velocities surface plasmons on a single interface are overdamped and evanescent in character. In addition, pulse spreading and the implications of the results for multilayer systems are discussed.
17 citations
TL;DR: In this article, electron beam lithography on the negative tone electron resist SU-8 was used to fabricate self-supporting three-dimensional structures in sub-micrometer range.
16 citations
TL;DR: The role of plasmon coupling and antenna effect in the surface‐enhanced Raman scattering enhancement is emphasized, and rings made of disk‐shaped particles and individual crescent‐ shaped particles are investigated.
Abstract: Summary
This article reports on the imaging of the surface plasmon fields of lithographically designed micrometre-sized gold structures. We investigate rings made of disk-shaped particles and individual crescent-shaped particles. These structures are imaged with two techniques, dark field imaging of elastically scattered light and imaging the surface-enhanced Raman scattering signal of methylene blue dye adsorbed onto the structures. Although elastically scattered light images result from the coherently summed contributions from all elementary scattering volumes, surface-enhanced Raman scattering images reflect the optical near-field intensity incoherently averaged over a surface area corresponding to the spatial resolution of the microscope objective. The combination of both imaging methods enables us to emphasize the role of plasmon coupling and antenna effect in the surface-enhanced Raman scattering enhancement.
14 citations