Ultraviolet Ion Laser Transitions between 2300 and 4000 Å

Fifty-five ultraviolet laser transitions in the wavelength region 2300–4000 Å have been observed from the ions of N, O, Ne, Ar, Kr, and Xe. The electron transition is p → s for all identified lines, with the exception of two xenon transitions which are p → d. Threshold currents for laser action in a 4-mm-bore tube were in the ranges 10–100, 100–500, and >400 A, respectively, for singly, doubly, and triply ionized atoms. Current saturation and current quenching of laser action both were observed. Results with two tube bores show that the usual inverse relation between gain and tube diameter does not hold in ultraviolet ion lasers.