The nitrogen ion laser

The characterization and thermal scaling of the nitrogen ion laser pumped by charge transfer from He(3-) is reported in this work. Intense laser emission in the violet at 427 nm has been observed and found to have a linewidth less than 0.3 A. The pumping ion, HE(3-), was produced by discharge of a fast-pulsed electron beam gun, APEX-1, into several atmospheres of a mixture of helium and nitrogen. Excitation current densities ranged from 1.1 to 2.5 sq cm at 1 MV over a 1 x 10 cm transverse geometry. Thermal scaling of the laser has been investigated and a strong inverse dependence of laser output on gas temperature was observed. Quasi-CW operation was achieved under these conditions suggesting that much longer output pulses might be obtained with an e-beam pulse of greater duration.