Laser action in Al II and He I in a slot cathode discharge

Abstract

Laser excitation of metal vapors and gases in four types of hollow cathodes employing transverse electrical discharges is discussed. A water‐cooled slot cathode is demonstrated to provide two distinct laser excitation modes. cw laser action at 7471, 7042, and 6920 Å from Al II, which is cathodically sputtered by Ne/H₂ mixtures and excited in charge‐transfer collisions, is reported. Pulsed laser action at 7065.21 and 7065.17 Å from He I, which is excited in direct electron impact collisions in the presence of H₂ is reported. Laser performance data relating to gas pressures, currents, pulse widths, and gains are presented. The importance of H₂ admixtures to the laser species is discussed.