Slow-molecule detection in Doppler-free two-photon spectroscopy
Laboratoire de Physique des Lasers, URA n. 282 du CNRS, Université Paris-Nord, Avenue J.-B. Clément, F-93430
Accepted: 2 December 1996
We present the first observation of optical detection of slow molecules by using Doppler-free two-photon spectroscopy (DFTPS). We obtained a linewidth of 280 Hz (HWHM) which is 23 times narrower than the transit broadening for the most probable velocity class. Slow-molecule two-photon resonances are, thus, very promising candidates for frequency standards in the infrared. This experiment was performed in the band of in the spectral region. It reveals also for the first time a magnetic hyperfine structure in molecular DFTPS.
PACS: 33.70.Jg – Line and band widths, shapes, and shifts / 33.80.-b – Photon interactions with molecules / 42.62.Fi – Laser spectroscopy
© EDP Sciences, 1997