Hybrid transitions in sodium dimers by laser absorption spectroscopy

Abstract

This paper reports the laser absorption transition from the molecular bound state X 1Σ + g of Na 2 to the repulsive hump of the otherwise bound state B 1Π u. The photodissociation of B 1Π u results in the production of 3 2P 1/2,3/2 state of atomic sodium. A photon of the same laser pulse causes an absorption transition from 3 2P 1/2,3/2 to the Na (6S) state. The excited Rydberg atom, on collision with other atoms, ionizes to produce an ion-current pulse in an ionization cell, which is subsequently processed by a box-car integrator and plotted on a chart recorder as a function of tunable dye laser photon energy. Such hybrid transitions simultaneously involving molecular and atomic states within the same laser pulse have been observed for other metals, as Rb or Cs, but are the first time being reported here for sodium. The present work establishes the correlation of the dimer state B 1Π u with both the terms ( J = 3 2 and J = 3 2 ) of the atomic doublet 3 2P 1/2,3/2 .