PERTURBATION FACILITATED OPTICAL-OPTICAL DOUBLE RESONANCE STUDIES OF THE $Na_{2} a^{1}\Sigma^{+}_{u}, b^{3}\Pi_{u}$, AND TRIPLET-GERADE RYDBERG STATES

Author Institution: Qinghai Institute of Salt Lake, Xining, Qinghai; Department of Chemisry, Massachusetts Institute of TechnologyVarious spin-orbit mixed $Na_{2} A^{1}\Sigma^{+}_{u} \sim b^{3}\Pi_{u}$ levels act as gateways into the triplet manifold. The following triplet-gerade Rydberg states have been characterized by sub-Doppler, OODR fluorescence excitation spectroscopy: $2 {^{3}}\Pi_{g}$(33 vibrational levels), $3 {^{3}}\Pi_{g}$(17 vibrational levels, absolute vibrational numbering), $1 {^{3}}\Pi_{g}$(3 vibrational levels), 4 or $5 {^{3}}\Sigma^{+}_{g}$ (1 vibrational level, absolute numbering), and $1 {^{3}}\Sigma^{-}_{g}$ (1 vibrational level). The high vibrational levels of $2 {^{3}}\Pi_{g}$ perturb most of the low levels of $3 {^{3}}\Pi_{g}$. The mechanism for violet fluorescence from $Na_{2}$ vapor is discussed. The $v=0-12$ levels of the $a^{3}\Sigma^{+}_{u}$ state are observed in rotationally resolved OODR dispersed ${^{3}}\Pi_{g}-a {^{3}}\Sigma^{+}_{u}$ fluorescence. The correct vibrational numbering of the $b^{3}\Pi_{u}$ state is established from short wavelength termination of several ${^{3}}\Pi_{g}-b{^{3}}\Pi_{u}$ fluorescence progressions