Berlin 2008 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 9: POSTERS Single Molecules, Biopolymers, Membranes

CPP 9.8: Poster

Monday, February 25, 2008, 16:45–19:00, Poster A

Higher order laser modes as a tool to determine single-molecule orientation in an optical microresonator — •Raphael Gutbrod, Anna Chizhik, Dmitry Khoptyar, and Alfred Johann Meixner — University of Tübingen, Institute for Physical and Theoretical Chemistry, Auf der Morgenstelle 8, 72076 Tübingen (Germany)

Subwavelength optical microresonators show great potential as a platform for single-photon emitting sources and sensors on the nano-scale. Due to modification of the optical state density inside the microresonator the emission properties of single molecules can be strongly modified, which includes spectral and spatial redistribution of the spontaneous emission as well as enhancement and inhibition of the spontaneous emission rate due to the Purcell-effect [1].

A recently developed technique for determination of single-molecule orientation is based on excitation with azimuthally and radially polarized doughnut laser modes. Analysing the single molecular excitation patterns with confocal microscopy allows one to determine the orientation for many molecules from one scan image.

Using a novel microresonator designed in our group we investigate the excitation patterns of fluorescent beads with these laser modes aiming at a better understanding of the cavity electrodynamics. This is a crucial point for optimal cavity design which may open a perspective for new integrated nano-optical sensing.

[1] M. Steiner, F. Schleifenbaum, C. Stupperich, A. V. Failla, A. Hartschuh, A. J. Meixner . ChemPhysChem 2005, 6, 2190