DPG Phi
Verhandlungen
Verhandlungen
DPG

Berlin 2001 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

MO: Molekülphysik

MO 10: Spectroscopy I: Ultra-short Time Spectroscopy

MO 10.7: Vortrag

Donnerstag, 5. April 2001, 17:15–17:30, H1058

THz Time-Domain Spectroscopy on Ammonia — •Hermann Harde1, Jianxin Zhao1, Marcus Wolff2, Alan Cheville2, and Daniel Grischkowsky21Universität der Bundeswehr Hamburg, Lasertechnik und Werkstoffkunde, Germany — 2School of Electrical and Computer Engineering, Oklahoma State University, USA

We use the technique of terahertz time-domain spectroscopy to experimentally and theoretically study the absorption and dispersion of ammonia vapor. Our measurements show small deviations from the rotation-inversion spectrum which originate from transitions in the ν2 hot band and from the (NH3)2 dimer. We investigate the molecular tunneling in ammonia and apply our new molecular response theory1 to analyze the inversion spectrum of this molecule. The theory includes the molecular response of polar molecules to an external electric field over the duration of a collision with the molecular response time as a control parameter, and it unifies the basic collision theories of Lorentz, van Vleck-Weisskopf and Debye. The calculated absorption and dispersion based on this theory fits the measurements over the full spectral range of the THz spectrum and allows to determine a response time of the order of 100 fs.

1. H. Harde, R. A. Cheville, D. Grischkowsky, J. Phys. Chem. A

101, 3646-3660 (1997)

100% | Mobil-Ansicht | English Version | Kontakt/Impressum/Datenschutz
DPG-Physik > DPG-Verhandlungen > 2001 > Berlin