Observation of UV and violet diffuse bands of sodium dimer excited by XeF (351 nm) excimer laser

We report on the observation of strong UV diffuse band around 380 nm in direct one photon excitation of sodium molecule using 351 nm laser radiation from an excimer laser. The emission, though less intense by an order of magnitude in comparison with the violet bands, shows a clear spectral narrowing with increasing temperature. In addition, we report some interesting parametric dependences of the violet diffuse bands in the region of 420-460 nm. The results may help in clarifying the nature of the processes involved in populating the upper levels responsible for these emissions which have lately been conclusively identified. (orig.)