Formation of Oriented Cesium Atoms upon Photodissociation of CsI Molecules via the Second Excited State

摘要

The detection and study of spin-oriented cesium atoms formed in the ground electronic state upon photodissociation of CsI molecules via the second excited state under irradiation with a circularly polarized laser beam at a wavelength of 266 nm are reported. The total angular momentum of atoms formed in this way precessed in an external magnetic field, which caused a cyclic change in atomic-vapor dichroism that was experimentally detected by a change in absorption of resonance radiation of the D1 line of cesium at a wave-length of 894.4 nm. The dependence of the signal of circular dichroism on the lamp operating mode is studied. The initial degree of spin orientation of cesium atoms was determined by extrapolation of experimental data to the zero intensity of laser radiation and was found to be equal to Pe 0.13 0.02. The result is compared with theoretical predictions, and possible mechanisms of photodissociation of alkali-halide molecules via the second excited state are discussed.