Stable single-frequency emission of an argon-ion laser under line competition conditions

An investigation was made of the possibility of single-frequency emission of an argon-ion laser in the case of the simultaneous activity of two coupled transitions 4p²D⁰_5/2 → 4s²P_3/2 and 4p⁴D⁰_5/2 → 4s²P_3/2. The coherent emission spectra of both transitions were investigated. The regions of normal and anomalous competition between these transitions were determined. The criteria for single-frequency emission were established. An oscillographic study was made of the dependence of the emission spectrum on the discharge parameters.