A HIGH-VOLTAGE HOLLOW-CATHODE AU-II 282-NM LASER

Laser operation on the Au-II 282.3-nm line is obtained from a high-vol tage, segmented hollow-cathode discharge tube with external mirrors. M easurements of the laser output power and the small-signal gain demons trate that, for a given total discharge current, the optimum performan ce of the laser is obtained for a discharge length for which the linea r current density is approximately 65 mA cm-1. The gain is approximate ly 25% m-1 at this current density and increases with current density up to the highest value used (250 mA cm-1), at which the gain exceeds 50% m-1. The threshold current decreases monotonically with decreasing length, the lowest observed value being 0.28 A for a length of 5 cm. A quasi-CW output power of 20 mW is obtained for a gain length of 20 c m and a discharge current of 3.2 A in a partially optimized tube with unoptimized output coupling.