Discharges for multi-colour CW lasers

A glow discharge has a number of distinct features, i.e. well developed dark and luminous zones can be identified, which are directly related to the spatial distribution of the electric field, space charge densities and current densities. In lasers both the positive column and the negative glow are utilized, the former usually for longitudinal discharges in capillaries, the latter in longitudinal or transversal hollow-cathode discharges. The author discusses the evolution and prospects of CW neutral atom and ion lasers of low and medium output power. Specifically some CW metal vapour lasers are addressed, a group of lasers which until to date somewhat lack the commercial success story of other gas discharge lasers