Direct excitation studies of the diffuse bands of alkali metal dimers

Abstract
Direct dye laser excitations of the K2 yellow, Rb2 orange, and Cs2 near-infrared diffuse bands have been investigated. Experimental results are shown to be consistent with the assumed bound–free 2 3Πg–1 3∑+u excitations. It is found that for Rb2 and Cs2, spin–orbit interactions become so significant that the 2 3Πg state is strongly split into three quite independent component states.