Optical pumping activity in Poland is reviewed with particular emphasis on Professor Kastler's inspiration in its development. The reviewed activity concerns studies of relaxation, modulation effects, level crossing and anticrossing effects, dressed atom model and of the forward scattering of resonance radiation.
In 1950, Professor Alfred Kastler described the way in which optical fields could be used to redistribute population among the Zeeman sublevels of a given atomic state. The « optical pumping » process discovered by Kastler continues to be a research topic of current interest. With developments in laser spectroscopy, it has become important to understand the interplay of optical pumping, transit-time and collisional effects to properly interpret experimental line shapes. A brief review of the current status of the theory is given, with special emphasis on what, as yet, appear to be unresolved problems. Velocity selective optical pumping and collision-induced resonances are discussed.
In a paper of 1950, Alfred Kastler proposed cooling of vapours by resonant light via optical pumping of the orientational levels of angular momentum, and successive collisions. Optical pumping of the degrees of freedom of the translational momentum is also feasible. This phenomenon has been demonstrated with ions, even with a single ion, in an electrodynamic or electromagnetic trap. Optical cooling by Raman-like two-photon transitions seems to be capable of generating ultra-low temperature levels.