Kinetic equations for optical pumping of alkali metal atoms with large hyperfine structure of the excited states

Yuan‐Yu Jau

In this thesis, we present new studies of alkali-hyperfine resonances, new optical pumping of alkali-metal atoms, and the new measurements of binary spin-exchange cross-section between alkali-metal atoms and xenon atoms. We report a large light narrowing effect of the hyperfine end-resonance signals, which was predicted from our theory and observed in our experiments. By increasing the intensity of the circularly polarized pumping beam, alkali-metal atoms are optically pumped into a state of static polarization, and trapped into the hyperfine end-state. Spin exchange between alkali-metal atoms has minimal effect on the end-resonance of the highly spinpolarized atoms. This new result will possibly benefit the design of atomic clocks and magnetometer. We also studied the pressure dependence of the atomic-clock resonance linewidth and pointed out that the linewidth was overestimated by people in the community of atomic clock. Next, we present a series study of coherent population trapping (CPT), which is a promising technique with the same or better performance compared to the traditional microwave spectroscopy. For miniature atomic clocks, CPT method is thought to be particularly advantages. From our studies, we invented a new optical-pumping method, push-pull optical pumping, which can pump atoms into nearly pure 0-0 superposition state, the superposition state of the two ground-state hyperfine sublevels with azimuthal quantum number m = 0. We believe this new invention will bring a big advantage to CPT frequency standards, the quantum state preparation for cold atoms or hot vapor, etc. We also investigated the pressure dependence of CPT excitation and the line shape of the CPT resonance theo-

Raoul Gregory Vitale

Alfred Kastler

In the optical excitation of atoms with polarized light, producing excited atoms, only some of the Zeeman sublevels of the excited state are actually reached, so that large differences of population can be built up between Zeeman sublevels or between hyperfine structure (hfs) levels. This property can be used to detect radio-frequency resonance in optically excited atomic states. These resonances produce a characteristic change in intensity or in the degree of polarization of the light re-emitted. Zeeman intervals, Stark effects, and hfs intervals can be measured in this manner. (The Stark constant of the 63P1 level of Hg and the electric quadrupole moments of the alkali atoms have been obtained in this way.)The technique of “optical pumping” gives a way to concentrate atoms in some of the Zeeman sublevels of one of the hfs levels of the ground state.Atomic orientation has been obtained with the Na atom, in an atomic beam and in the vapor in equilibrium with the metal. The orientation effects have been studied by detection of radio-frequency resonance signals in the ground state. Orientation can be increased many times by adding a variable pressure of a foreign gas to the pure Na vapor. Because of the coupling between nuclear spin and electron spin, nuclear orientation is produced at the same time as atomic orientation.

Yu. L. Malinkevich

Małgorzata Głódź, M Krainska-Miszczak

In investigations of hyperfine structure (hfs) by the quantum beat method, the two-photon excitation scheme was introduc to4tta a numb of highly excited D states of some alkali metal isotopes ( K, K, Rb and Rb). In the present paper some details of the experimental technique are presented. The values of the magnetic-dipole interaction constant A and the electric-quadrupole interacion constant B, obtained in a series of experiments for the states of interest (6 D312 5/2 of 39K, 62D312 of 41K, l1,122D312 of °5Rb, lO-132D312 and 9-132D512 of 87Rb) are summarized and compared with other results concerning hfs of the D states of the same isotopes. The relatively simple method proved to be quite effective .n extending the measurements of hyperfine interaction constants to highly excited D states of alkali metal atoms.

Brian Patton, Kiyoshi Ishikawa, Yuan‐Yu Jau +1 more