The phenomenological Bloch equations are solved for transient nutation in optical two-level systems, using the Feynman-Vernon-Hellwarth representation. The resulting solutions display an exponentially damped oscillatory behavior, from which the relaxation times T1 and T2 may be derived. Transient nutation signals were observed using time-resolved microwave spectroscopy with rapid switching of applied Stark fields. Observed collision relaxation rates are (5.25 ± 0.50) MHz/torr for OCS-OCS, (1.96 ± 0.30) MHz/torr for OCS-He and (1.67 ± 0.20) MHz/torr for OCS-Ar. For NH3NH3 relaxation the rate is (23.2 ± 3.5) MHz/torr for the (8,7) inversion line.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry