Hamburg 2009 – scientific programme
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MO: Fachverband Molekülphysik
MO 18: Experimentelle Techniken
MO 18.4: Talk
Thursday, March 5, 2009, 11:30–11:45, VMP 6 HS-F
Absolute absorption spectroscopy based on molecule interferometry — •Stefan Nimmrichter1, Klaus Hornberger2, Hendrik Ulbricht3, and Markus Arndt1 — 1Faculty of Physics, University of Vienna, Boltzmanngasse 5, 1090 Vienna, Austria — 2Arnold Sommerfeld Center for Theoretical Physics, Ludwig-Maximilians-Universität München, Theresienstraße 37, 80333 Munich, Germany — 3School of Physics and Astronomy, University of Southampton, Highfield Southampton SO17 1BJ, United Kingdom
We propose a method [1] to measure the absolute photon absorption cross section of neutral molecules in a molecular beam. It is independent of our knowledge of the particle beam density, nor does it rely on photo-induced fragmentation or ionization. The method is based on resolving the recoil resulting from photon absorption by means of near-field matter-wave interference, and it thus applies even to very dilute beams with low optical densities. In case of fluorescing molecules the quantum yield can be measured as well. We account for the influence of realistic experimental uncertainties and show that the precision of our scheme compares favorably with direct extinction and depletion experiments using existing technologies.
[1] S. Nimmrichter, K. Hornberger, H. Ulbricht and M. Arndt, PRA (in press, eprint on arxiv:0811.1141)