Düsseldorf 2007 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 73: Laserspektroskopie II
Q 73.5: Vortrag
Freitag, 23. März 2007, 15:00–15:15, 5K
Ultra-sensitive surface absorption spectroscopy using sub-wavelength diameter optical fibers — •Eugen Vetsch1,2, Florian Warken1, Dieter Meschede1, Moritz Sokolowski3, and Arno Rauschenbeutel1,2 — 1Institut für Angewandte Physik, Universität Bonn, Wegelerstr. 8, 53115 Bonn — 2Institut für Physik, Universität Mainz, Staudingerweg 7, 55128 Mainz — 3Institut für Physikalische und Theoretische Chemie, Universität Bonn, Wegelerstr. 12, 53115 Bonn
The guided modes of sub-wavelength diameter optical fibers exhibit a pronounced evanescent field surrounding the fiber. The absorption of particles on the fiber surface is therefore readily detected via the fiber transmission. We show that the resulting absorption signal for a given surface coverage can be orders of magnitude higher than for conventional surface spectroscopy methods. As a demonstration, we present measurements on sub-monolayers of 3,4,9,10-perylene-tetracarboxylic dianhydride (PTCDA) molecules at ambient conditions, revealing the agglomeration dynamics on a second to minutes timescale.
We acknowledge financial support by the DFG research unit 557.