Abstract

We have measured photoelectron angular distributions for single photon ionization of atomic rubidium and cesium and for two photon ionization of rubidium. The single-photon measurements show clear variation as a function of wavelength of the exciting laser due to the spin-orbit interaction. From these measurements we derive the Fano parameter, a measure of the relative strength of the dipole transition amplitudes from the ground state to the j = 1/2 and j = 3/2 continuum p states. These results are in excellent agreement with, and in some cases of much smaller uncertainty than, similar results obtained through measurements of the Fano effect and related polarization measurements. The two-photon measurements also vary with wavelength because of their dependence on relative cross sections and phase shifts of the p → d and p → s transitions, and the fine structure of the continuum d-state.

© 1992 Optical Society of America