Near ultraviolet operation of argon and krypton ion lasers

Several reports on operation of ion lasers on the transitions between states in doubtedly ionized argon and krypton (Ar III and Kr III) leading to oscillation in the near ultraviolet have been given in the last three years (1-3). These reports deal with ultraviolet operation utilizing plasma tubes specifically designed to achieve high current densities. We have experimented with production models of argon and krypton ion lasers of several sizes to determine if useful ultraviolet performance may be obtained with them. Bore sizes, tube active discharge lengths, tube currents, and axial magnetic fields are typical of those used for visible ion laser operation. With these tubes and careful attention to internal cavity losses, lower thresholds than previously reported and useful ultraviolet output has been achieved.