 
Summary: 1467
Laser Physics, Vol. 13, No. 12, 2003, pp. 14671477.
Original Text Copyright © 2003 by Astro, Ltd.
Copyright © 2003 by MAIK "Nauka /Interperiodica" (Russia).
1. INTRODUCTION
It is well known that the application of an external
magnetic field modifies the absorptive and dispersive
properties of an atomic system. As the magnetic field
strength starts to increase from the zero value, the
degeneracy of atomic states lifts and magnetic sublev
els diverge. A linear shift of these sublevels takes place
until the B field reaches values for which the Zeeman
splitting becomes comparable to the hyperfine splitting
of atomic levels. In this regime, the wavefunctions of
the hyperfine manifold begin to mix with each other.
This mixing results in dual consequences. First, the
shift of the magnetic sublevels is no longer linear on the
B field (and of different behavior for different individ
ual sublevels). Second, the probabilities of the optical
transitions between the magnetic sublevels of the lower
