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DS: Fachverband Dünne Schichten

DS 36: Plasmonics and Nanophotonics HL-I (jointly with HL and O)

DS 36.6: Vortrag

Mittwoch, 16. März 2011, 11:30–11:45, POT 251

Angle-resolved fluorescence spectroscopy in photonic crystals — •Rebecca Wagner, Lars Heerklotz, and Frank Cichos — Molecular Nanophotonics, University of Leipzig, Germany

Photonic Crystals (PCs) are materials with periodically varying dielectric constant. Multiple scattering of light on this spatially modulated refractive index leads to the formation of a photonic band structure including photonic band gaps. The optical density of states is redistributed as compared to a homogeneous material and is described by the fractional local density of states (FLDoS). This leads to a modified propagation of light in the material.

The spectral and angular position of the band gaps can, for example, be probed by reflection spectroscopy. Since reflections can occur on different lattice plane families, the detection angle has to be varied for every angle of incidence, making this method very time consuming. Further, an average of the reflectivity over differently oriented crystal domains is taken.

We develop a method to overcome these problems using fluorescence spectroscopy of single internal emitters. By applying a special technique we are able to measure angle resolved fluorescence spectra for many emission angles at the same time. Comparison of these spectra to spectra of emitters outside the PC gives the FLDoS, which also contains information about the symmetry of the emitter's local environment. By varying emitters and lattice constants of the PC, different regions of the band structure can be probed.