Düsseldorf 2007 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 29: Poster: Cold Molecules
MO 29.3: Poster
Dienstag, 20. März 2007, 16:30–18:30, Poster A
Spectroscopy of the X1A1 → A1A2 transition of formaldehyde in the 329-331.7 nm region: The 201403 rovibrational band — •Michael Motsch, Markus Schenk, Martin Zeppenfeld, Pepijn W.H. Pinkse, and Gerhard Rempe — Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching, Germany
Optical manipulation of cold polar molecules necessitates a molecule with strong electronic transitions, preferably in a spectral region accessible with standard cw-laser techniques, and a large Stark shift for efficient electric guiding and trapping. Slow beams of up to 1010 s−1 formaldehyde molecules with velocities around 50 m/s have been produced [1]. Moreover formaldehyde (H2CO) exhibits a rich ultraviolet spectrum between 280 and 360 nm [2].
Room-temperature absorption spectroscopy is performed in a multi-pass setup at H2CO pressures of 50 Pa. The use of a frequency-doubled cw dye laser allows higher resolution than previous studies relying on pulsed dye lasers [3]. Comparison between calculations based on available rotational constants and our measurement indicates the necessity to include sixth-order centrifugal distortion coefficients.
Progress towards state-dependent detection of electrically guided formaldehyde molecules is discussed.
[1] S.A. Rangwala et al., Phys. Rev. A 67, 043406 (2003)
[2] G. Herzberg, Molecular Spectra and Molecular Structure 3, Van Nostrand Reinhold Company, New York 1966
[3] C.A. Smith et al., J. Phys. Chem. A 110, 11645-11653 (2006)