Signal Parameters in Optical Pumping Experiments

L. Dellit

Abstract The features of fluorescence and transmission signals in optical pumping of dilute gases with non‐coherent light sources are discussed in terms of a generalized signal function. Using the spherical tensor operator formalism kinetic equations for the atomic state multipoles as well as rate equations for spontaneous emission and absorption are derived. In these rate equations the kinetics of the atomic system expressed by the, generally, time dependent state multipoles of the atomic distribution in the ground or excited state is weighted by the optical signal parameters to give a signal function, which is explicitly adapted to the experimental conditions of observation.

J. Brossel

Emilia A. Alipieva, Svetlana Karabasheva

We report magneto-optical rotation due to the interaction of atoms with a resonance laser beam. Our experiment is performed on the excited He states, 23P-33D transition, (lambda) equals 587,56nm. Two processes are responsible for the magneto-optical activity: the Zeeman coherences, induced in the absorbing level, and the optical pumping processes, each of them due to the laser beam excitation. The Zeeman coherence creates peaks with a width determined by the coherence relaxation rate, while the optical pumping creates a structure with a width in the order of the natural width of the transition. Due to the difference between the relaxation rates of the 2P and 3D He levels, the two parts of signal are well resolved and depend on the He pressure in different ways. The narrow coherence signal disappears at high He pressure, unless the amplitude of the optical pumping signal increases. The optical pumping signals saturates as He pressure increased and changes its sign. At high gas pressures, such that only the optical pumping signal exists, an increase of the He pressure leads to the narrowing of both the 'classical parabolic dependence' and the optical pumping signal.

Noriaki Tsukada

Arnold L. Bloom, William E. Bell

Xiaoping Zhang

Optical pumping signal subjected to a scanning magnetic field was experimentally observed.According to the theory of atom radiation transition,a simplified energy model of optical pumping was established and the equation of transition rate was set based on the optical pumping magnetic resonance experiment.The dependences of the signal intensity and relaxation time on the magnetic field were numerically calculated,and the results were in good agreement with the experiment.