A theoretical study of anisotropic collisional relaxation within the hyperfine structure of a cadmium atom upon laser excitation

Journal Article · Fri Dec 01 04:00:00 EST 1995 · Optics and Spectroscopy

OSTI ID:232887

Petrashen`, A G; Rebane, V N; Rebane, T K ^[1]

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1. St. Petersburg (Russian Federation)

The anisotropic collisions relaxation of electron-nuclear polarization moments of hyperfine structure (HFS) sublevels of the F = 1/2, 3/2 doublet belonging to the 5s5p {sup 3}P{sub 1} electronic state of the investigated upon monochromatic laser excitation in the atmosphere of various rare gases. The anisotropic collisional relaxation rate constants of polarization moments of different ranks are calculated as a function of the laser detuning from the center of the Doppler contour. The process of the combined collisional relaxation of populations of the HFS doublet levels and longitudinal alignment of the F = 3/2 level resulting in the collisional alignment and the associated linear polarization of light, as well as the process of the combined relaxation of the alignment inclined to the laser beam and the transversal to this beam orientation of atomic angular momenta resulting in the collisional generation of circular polarization are studied. The dependence of the collisional population transfer between the HFS sublevels on the laser frequency and the alignment of the F = 3/2 level is studied as well. For each of these processes, the dependence of corresponding intensity and polarization signals both for the usual and for the sensitized fluorescence emitted from the HFS doublet levels are calculated as a function of the laser frequency and the rare gas (Ne, Ar, Kr, and Xe) pressure. The specific feature of anisotropic collisional generation of the alignment and the orientation signals is their disappearance with the change of their sign at the laser frequencies, corresponding to the transformation from anisotropic to quasi-isotropic collisional relaxation. As a result, these signals are almost half the width of the Doppler contour. This fact is employed in sub-Doppler polarization spectroscopy. 14 refs., 7 figs., 1 tab.

• OSTI ID: 232887
• Journal Information: Optics and Spectroscopy, Journal Name: Optics and Spectroscopy Journal Issue: 6 Vol. 79; ISSN OPSUA3; ISSN 0030-400X
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ATOM COLLISIONS
CADMIUM 113
EXCITATION
HYPERFINE STRUCTURE
LASER RADIATION
RELAXATION
SPIN ORIENTATION