The effect of different populations of the magnetic sublevels of the ground state on the propagation of polarized radiation through resonant media is studied theoretically. The nonlinear refractive indices for circularly and linearly polarized waves in media with arbitrary angular momenta j 1 and j 2 are found. The influence of the coherence between the magnetic sublevels on multiphoton effects is analyzed. It is shown that, as a result of elastic Rayleigh scattering, energy transfer from one component of the wave polarization to the other takes place. The picture of induced four-photon parametric scattering of a weak wave in the presence of a strong wave also changes.
In a magnetic field, the wave number of a pump laser light polarized along the field was fixed to the isolated ${\mathrm{Cs}}_{2}D{}^{1}{\ensuremath{\Sigma}}_{u}^{+}(v=46,J=54)\ensuremath{\leftarrow}X{}^{1}{\ensuremath{\Sigma}}_{g}^{+}(v=0,J=55)$ line, and the excitation spectrum of the dissociated
Cs(6p2P3/2) atoms was measured by scanning the wave number of a probe laser light polarized perpendicular to the field. The population of each sublevel
6p2P3/2,mj of the dissociated atoms was determined from the line intensities in the
mj-resolved excitation spectrum. The unequal population between the
6p2P3/2,+∣mj∣ and $6p{}^{2}{P}_{3/2,\ensuremath{-}|{m}_{j}|}$ levels (atomic orientation) was observed and it was enhanced as the magnetic-field strength was increased. The atomic orientation is shown to be induced by the interference between the indirect predissociation, which occurs by a combination of the spin-orbit coupling of the $D{}^{1}{\ensuremath{\Sigma}}_{u}^{+}$ state with the ${(2)}^{3}{\ensuremath{\Pi}}_{0u}$ state and the L-uncoupling and Zeeman interactions between the ${(2)}^{3}{\ensuremath{\Pi}}_{0u}$ and dissociative ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ states, and the dissociation following a direct excitation to the ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ state, which is allowed by spin-orbit coupling of the ${(2)}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ state with the $B{}^{1}{\ensuremath{\Pi}}_{u}$ state. It is demonstrated that the atomic orientation is produced by the photodissociation in the presence of an external magnetic field even when all degenerated molecular $M=J,\dots{},0,\dots{},\ensuremath{-}J$ sublevels are excited by a light polarized linearly along the field.
A theoretical analysis is made of the resonant interaction between a traveling monochromatic light wave of arbitrary intensity and polarization and the 1/21/2 and 10 transitions in gas atoms in a magnetic field. An analysis is made of the influence of atomic collisions and coherence of the Zeeman sublevels of the terms on the structure of nonlinear magnetooptic resonances in the amplitude and polarization characteristics of the wave. Some features of nonlinear magnetooptic resonances for laser excitation of atoms from the ground state are noted. A study is made of the Faraday rotation and self-rotation of the polarization ellipse of the radiation as a function of the detuning of the wave frequency, the saturation parameter, and the optical density of the gas. The stability of the polarization of light in the medium is discussed. It is noted that these laws may be used to analyze and control the radiation characteristics of lasers and amplifiers when the level of saturation of a resonant gaseous medium in a magnetic field is high.