Critical prepulse densities of electrons and metastable states in copper vapour lasers

Two mechanisms of population inversion quenching were considered based on a detailed model of the active medium of a copper vapour laser. One of them is due to a high prepulse density of metastable states and the other is due to a high prepulse electron density. For a given pumping system, lasing was shown to terminate when the initial densities of metastable states or electrons exceeded some critical values. The results of calculations of the critical initial electron density are consistent with our simple estimates proposed earlier.