Optical Alignment and Collisional Disalignment of Pb Metastable States

V. N. Rebane, T. K. Rebane

Leslie Pendrill, George William Series

Cross sections for the disalignment of excited caesium atoms, by collision with atoms in ground states, have been determined by studying the damping of quantum beats in fluorescence. Atoms in a sealed cell were excited selectively to 122D3/2 and 132S3/2 by a pulsed tunable laser and discharge lamp. Alignment was induced by linear polarisation of the exciting light and monitored correspondingly. The quantum beats originate in the coherent excitation of hyperfine states whose structures have been determined in previous work. Collisional damping is investigated studying the quantum-beat signal over a range of atomic densities. The fluorescence contains a component representing the decay of population as well as of alignment, and extraction of the alignment cross sections relies on previous measurements of the depopulation cross sections. The results for disalignment cross sections are: sigma (2)(122D3/2)=4.1+or-0.8*10-16 m2, sigma (2)(132D3/2)=5.3+or-0.9*10-16 m2, about three times larger than the depopulation cross sections. Radiative lifetimes obtained from the analysis agree with previous determinations.

Bertram Parister

Christopher Reiser, Nicholas Djeu, R. D. Burnham

Collisional quenching of the two lowest Pb atom metastable levels, 6p2 3P1 and 6p2 3P2, has been studied at Pb vapor densities of (1–20)×1016 cm−3. The metastable atoms were created in a heat pipe oven by stimulated Raman scattering using an XeCl laser pump. Their subsequent decay was then probed with tunable, single-frequency UV on the 266.3 and 261.4 nm Pb resonance lines. The observed rate constants are 2.0×10−13 cm3 sec−1 for 3P1 and 3.2×10−13 cm3 sec−1 for 3P2.

Gianni Di Domenico, Hervé Saudan, G. Bison +2 more

We present an experimental study of the intrinsic magnetometric sensitivity of an optical or rf-frequency double-resonance magnetometer in which linearly polarized laser light is used in the optical pumping and detection processes. We show that a semiempirical model of the magnetometer can be used to describe the magnetic resonance spectra. Then, we present an efficient method to predict the optimum operating point of the magnetometer, i.e., the light power and rf Rabi frequency providing maximum magnetometric sensitivity. Finally, we apply the method to investigate the evolution of the optimum operating point with temperature. The method is very efficient to determine relaxation rates and thus allowed us to determine the three collisional disalignment cross sections for the components of the alignment tensor. Both first and second harmonic signals from the magnetometer are considered and compared.