Study of the UV emission of an inductive nitrogen laser

Lasing at 337.1 and 357.7 nm is obtained upon excitation of nitrogen molecules by a toroidal pulsed inductive discharge. A system for formation of a pulsed inductive discharge for exciting gas lasers is described. The spontaneous emission spectra of the nitrogen inductive discharge plasma and the emission spectrum of the nitrogen laser are recorded and interpreted. The dependences of the energy and duration of laser pulses on the resonator Q factor and pump level are studied. The output energy of the inductive nitrogen laser emitting 15 ± 1-ns pulses achieves 4.5 mJ. The generation of high-power 300-kW pulses is obtained for the first time at a low (~1 Torr) pressure of pure nitrogen. The spatial distribution of the laser radiation intensity in the discharge tube cross section is investigated. The cross section of the radiation beam of the inductive nitrogen laser had the shape of a ring with the external diameter of 34 mm and width ~4 mm, its divergence being ~0.8 mrad. The average output power of the laser achieved 120 mW at a pulse repetition rate of 30 Hz.