Ai. Alekseev et Na. Korotkova, EFFECT OF OPTICAL-PUMPING IN THE MAGNETIZATION OF ATOMS WITH A HYPERFINE-STRUCTURE OF LEVELS, Laser physics, 5(6), 1995, pp. 1147-1163
Light-induced magnetization of a gas containing active atoms with a hy
perfine structure of levels is studied. In the performed calculations,
we use the perturbation theory and assume that the central frequency
of an ultrashort light pulse propagating through the gas is close to t
he transition frequency omega(ba) = (E(b) - E(a))HBAR(-1), where E(a)
and E(b) are the energies of the ground and excited atomic levels, res
pectively, without allowance for hyperfine interaction. Two magnetizat
ion mechanisms are revealed. The main mechanism of light-induced magne
tization is associated with resonant interaction, which is responsible
for the redistribution of atoms in a gas with respect to the projecti
ons of the total momentum in resonant sublevels. Such redistribution e
xerts a considerable influence on the magnetic moment of each atom, An
other mechanism of light-induced magnetization is associated with opti
cal pumping, which transfers atoms from the resonant sublevel of the g
round state E(a) to all the sublevels of the same ground state allowed
by the selection rule in the total momentum, as well as to the sublev
els of a metastable state E(c) for atoms with Lambda-configuration of
levels, E(a) < E(c) < E(b). The total light-induced magnetization is e
qual to the sum of the contributions associated with resonant interact
ion and optical pumping. Therefore, the total magnetization depends on
the total momenta of atoms in all above-specified sublevels of hyperf
ine structures. We revealed a peculiar hyperfine structure in the ligh
t-induced magnetization of a gas, which is manifested when we scan the
central frequency of the incident ultrashort light pulse. The conclus
ions of our analysis are illustrated by specific examples of rubidium
and indium atoms with a doublet splitting of the ground and excited st
ates E(a) and E(b).