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J Boneberg

Publications and source records attributed to J Boneberg.

5 recordsLinked to original sources
PubMed2005

Jumping nanodroplets.

Flat gold nanostructures on inert substrates like glass or graphite were illuminated by single intensive laser pulses with fluences above the gold melting threshold. The liquid structures produced in this way are far from their equilibrium shape, and a dewetting process sets in. On a time scale of a few nanoseconds, the liquid contracted toward a sphere. During this contraction, the center of mass moved upward, which could lead to detachment of droplets from the surface due to inertia. The resulting velocities were on the order of 10 meters per second for droplets with radii in the range of 100 nanometers.

Journal Article↗
PubMed2001

Local field enhancement effects for nanostructuring of surfaces.

We report on a method that allows the nanostructuring of surfaces with intense laser pulses. For this purpose isolated polystyrene spheres with diameters in the order of the laser wavelength were deposited on a silicon or glass surface. Illumination with short and ultrashort laser pulses produced holes underneath these particles. Calculations of the field near the particles make clear that geometrical optics, that is, focusing by a spherical lens, as well as near-field effects, contribute to the size and shape of these holes. This technique can be utilized for the parallel structuring of large surface areas with a single laser shot.

Journal Article↗
PubMed2000

Direct observation of the dynamics of electronic excitations in molecules and small clusters

Femtosecond time-resolved photoelectron spectroscopy is applied to study relaxation paths of excited states of mass-selected negatively charged clusters. As a first example, the lifetime of an excited state of the carbon trimer anion is measured directly. In addition, the mechanism of the decay, i.e., the configurations of the participating electronic states, is determined from the photoelectron spectra. In general, this method can be used to study all kinds of electronic excitation and relaxation processes in mass-selected nanoparticles.

Journal Article↗