Line competition in gas lasers

Simultaneous lasing on two lines having a common upper level is analysed. Within the framework of the two-level model, a formula for the gain in each line is obtained. Two possible types of line competition are found: symbiosis and quenching. It is shown that competition in the quenching regime can be used to study the rates of population of the lower levels. The results are illustrated by competition diagrams for the 2.65-μm and 2.03-μm of the Xe atom in the Ar — Xe mixture and the 703.2-nm and 724.5-nm lines of the Ne atom in the Ne — Ar mixture.