Theory has predicted highly unusual phenomena for negative-refractive index materials. For example, a two-level system can be located in its own image if a “perfect lens” is located in front of a mirror. This clearly drastically changes its spontaneous-emission behavior. Recently, negative-index metamaterials have become available at optical frequencies – in our group even in the visible regime (Opt. Lett. 32, 53 (2007); Science 315, 47 (2007)). Thus, the Ph.D. project envisioned here aims at performing corresponding quantum-optical experiments.
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Prof. Dr. Martin Wegener
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Dr. Stefan Linden
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Optical tweezers have become a valuable tool for manipulating sub-micrometer objects in biological systems. However, the size of particles that can be held is limited by the focus diameter, i.e. by the wavelength of light. Thus, particles of just a few nanometers in size can not routinely be handled. Plasmonics offers highly unusual dispersion relations of light corresponding to X-ray wavelengths at optical frequencies. This allows for much smaller “foci” of light than in conventional optics. The aim of this project is to realize plasmonic optical tweezers using specific tailored metallic nanostructures.
Contact:
Prof. Dr. Martin Wegener
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Dr. Stefan Linden
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Quasicrystals are a class of lattices characterized by a lack of translational symmetry. Nevertheless, the points of the lattice are deterministically arranged, obeying rotational symmetry. Recently (Nature Mater. 5, 942 (2006)), we have fabricated the first three-dimensional photonic quasicrystals at optical frequencies by using direct laser writing and the photoresist system SU-8. Preliminary experiments and theory suggest highly unusual optical properties. The aim of this Ph.D. thesis is to investigate these properties, e.g. by spectrally-resolved Laue diffraction experiments.
Contact:
Prof. Dr. Martin Wegener
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Dr. Georg von Freymann
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