Regensburg 2010 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 7: Electronic and Optical Properties of Organic Systems II

CPP 7.1: Vortrag

Montag, 22. März 2010, 14:00–14:15, H39

Controlling the optical properties of single molecules by optical confinement in a tunable microresonator — •Alexey Chizhik, Raphael Gutbrod, Anna Chizhik, Sebastian Baer, and Alfred Meixner — Institute of Physical and Theoretical Chemistry, University of Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen, Germany

We present experimental results on changing the fluorescence spectrum of a single dye molecule by embedding it within a tunable optical microresonator with subwavelength spacing. The resonator length is reversibly changed across the entire visible range with nanometer precision by using a piezoelectric actuator. By varying its length, the local mode structure of the electromagnetic field is changed together with the radiative coupling of the emitting molecule to the field. Since mode structure and coupling are both frequency dependent, this leads to a renormalization of the emission spectrum of the molecule. Moreover, we demonstrate how one can modify the ratio between the on- and off-axis photo emission of the molecules in the cavity. In addition, we use cylindrical vector laser beams (also known as doughnut laser modes) in the tunable microcavity to determine the longitudinal position of an isotropic emitter. By analyzing the excitation patterns resulting from the illumination of a single fluorescent bead in the focus of a radially polarized doughnut mode laser beam we can determine the longitudinal position of this bead in the microcavity with an accuracy of a few nanometers.