PULSED OPTICAL-OPTICAL DOUBLE RESONANCE OF THE GERADE EXCITED STATES OF $Li_{2}{^{*}}$

Abstract

Pulsed optical-optical double resonance using two tunable dye lasers pumped by a nitrogen laser was used to examine highly excited gerade singlet states in $Li_{2}$. The experimental arrangement has been previously $reported.^{1}$ Rotational relaxation in the $A^{1}\Sigma_{u}{^{+}}$ state allows many rotational levels to be probed with one pump line. Five new electronic states were observed. The $F^{1}\Sigma_{g}{^{+}}$ state at $29972 cm^{-1}$ was fit with a $\sigma= .15$ $cm^{-1}$. This state has a negative $\alpha_{e}$ rotational constant and several perturbed lines were observed. This state is also the final state for several resonantly enhanced two-photon transitions in the R6G region. The $G^{1}\Pi_{g}$ state was observed at $31868 cm^{-1}$ with a fit of $0.15 cm^{-1}$.