Harald Ditlbacher

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We report on chemically prepared silver nanowires (diameters around 100 nm) sustaining surface plasmon modes with wavelengths shortened to about half the value of the exciting light. As we find by scattered light spectroscopy and near-field optical microscopy, the nonradiating character of these modes together with minimized damping due to the well(More)
Dimensionality has a significant impact on the optical properties of solid-state nanostructures. For example, dimensionality-dependent carrier confinement in semiconductors leads to the formation of quantum wells, quantum wires and quantum dots. While semiconductor properties are governed by excitonic effects, the optical response of metal nanostructures is(More)
We map the complete plasmonic spectrum of silver nanodisks by electron energy loss spectroscopy and show that the mode which couples strongest to the electron beam has radial symmetry with no net dipole moment. Therefore, this mode does not couple to light and has escaped from observation in optical experiments. This radial breathing mode has the character(More)
Basic optical elements for surface plasmons are fabricated and their functionality (focusing, refraction, and total internal reflection) is demonstrated experimentally. The optical elements consist of dielectric structures of defined geometry on top of a gold film. The working principle of these structures is discussed on the basis of calculated surface(More)
We investigate electron-energy-loss spectroscopy (EELS) on metallic nanoparticles, through simulations, and provide a comprehensive comparison between EELS and the photonic local density of states (LDOS). Most importantly, we show that there is no direct link between EELS and LDOS maps, and that EELS can even be blind to hot spots in the gap between coupled(More)
The excitation of surface plasmon polaritons (SPP) by focusing a laser beam on single subwavelength holes opened in a thin gold film is studied both experimentally and theoretically. By means of leakage radiation microscopy, quantitative measurements of the light-SPP coupling efficiency are performed for holes with different sizes and shapes. The system is(More)
The present insight into plasmon effects on the nanoscale seems sufficiently advanced to allow the development of surface-plasmon-polariton- (SPP-) based optical devices. Therefore quantitative information describing SPP phenomena is required. We investigate a SPP beam splitter constituted by silver nanoparticles on a silver thin film, fabricated by(More)
In metal nanoparticles the resonance wavelength of light-driven collective electron oscillations is determined by the particle shape. This shape dependence can be used for optical data storage by spectral coding. In this way the storage density can be increased by at least a factor of 5 compared with that for conventional optical storage principles.
We report the experimental realization of key elements of a two-dimensional optics based on surface plasmon polaritons (SPPs). Local SPP sources, Bragg mirrors and beamsplitters were lithographically built from silver nanostructures. The SPP fields were imaged by detecting the fluorescence of molecules that act as local probes of the SPP near-field(More)
We describe a surface plasmon polariton- (SPP-) based device for measuring the intensity distribution of strongly focused light beams. A gold thin film configured as a sharp step is positioned in the focal region of a light beam, converting light into SPPs. The SPPs emit directional leakage radiation into the glass substrate beneath the thin film. The(More)