LINE-SHAPE STUDIES IN HIGH-RESOLUTION STIMULATED RESONANCE RAMAN-SPECTROSCOPY AND APPLICATION TO ACCURATE DETERMINATIONS OF HYPERFINE SPLITTINGS IN I-2
Cj. Borde et al., LINE-SHAPE STUDIES IN HIGH-RESOLUTION STIMULATED RESONANCE RAMAN-SPECTROSCOPY AND APPLICATION TO ACCURATE DETERMINATIONS OF HYPERFINE SPLITTINGS IN I-2, Journal of the Optical Society of America. B, Optical physics, 13(9), 1996, pp. 1837-1848
We studied stimulated resonance Raman transitions between hyperfine su
blevels of the ground electronic state X(1) Sigma(0+g)(v = 0, J = 13)
of I-2. Resonances narrower than 10 kHz (HWHM) were obtained. A detail
ed theoretical and experimental analysis of the line shape is presente
d. The pressure broadening of Raman resonances was found to be 7 +/- 1
kHz/mTorr. The role of the beam divergence was investigated and shown
to yield only a small broadening but some asymmetry of the lines. In
the transit-time limit the theory predicts that the slow molecules sho
uld play a dominant role, as in saturation spectroscopy. Our experimen
tal conditions are very close to that regime, and we discuss the impro
vements that should be made in order to reach it in future experiments
. Finally, six hyperfine splittings of the ground state of I-2 were de
termined with a 0.2-kHz accuracy. (C) 1996 Optical Society of America.