A study of rare gas spectra and their effect on pumping efficiencies of Neodymium lasers

A twenty-five per cent decrease in the threshold energy necessary to produce lasing action in neodymium can be expected when a change is made from xenon to krypton-filled flash lamps. In particular, a drop in threshold energy from 22.8 joules to 17.0 joules was observed by changing to krypton and optimizing the lamp pressure, all other parameters remaining constant. Spectral distribution curves are shown for xenon, krypton, argon, and neon which indicate the behavior of the various gases with changes in lamp pressure and current density. A comparison is made between these distributions and the absorption spectrum af neodymium, the analysis of which provides an explanation for the various pumping efficiencies observed.