The pumping efficiency of copper halide lasers

A simple relation between the copper halide laser output and the densities of ground state (²S) and metastable state (²D) copper atoms was found. This relation was used to analyze the experimental results of Nerheim. In all the analyzed systems it was found that about four percent of the ground state copper atoms take part in the lasing process. This may have implications for the efficiency of copper halide lasers.