Laser spectroscopy of spontaneous coherence transfer and optically induced polarization rotation in [formula omitted

Abstract

Spontaneous coherence transfer in 87 Rb atoms has been studied experimentally using a two-color laser polarization spectroscopy. Two classes of optical transitions were investigated for that the theory predicts a presence or absence of anisotropy of a ground state hyperfine sublevel 5 S 1/2 (F=1) populated via spontaneous decay of the 5 P 1/2 (F ′=1,2) excited states optically pumped by a strong linearly polarized laser beam. The anisotropy was controlled by the polarization rotation of another weak probe laser beam. A qualitative agreement with theory has been found at low ( 3–10 mW/ cm 2 ) pumping intensity. However, no significant changes in the rotation angles were observed after increasing the intensity to 70 mW/ cm 2 . A conclusion has been made that the spatial distribution of the pumping beam became important at high intensity.