Three phase excitation of a hollow cathode laser

A new hollow cathode discharge scheme utilizing three phase electrical power at 60 Hz to generate excitation in a sputtered He-Cu laser has been demonstrated. Our results indicate that rectified laser output can be obtained from an unrectified ac power supply using overlapping excitation regions, each excited with a different electric phase. Two preliminary hollow cathode designs are presented, one a tandem and one a transverse configuration. We achieved a rectified or quasi-dc output power of 350 mW. The use of overlapping ac excitation is seen to increase the operating life of a sputtered He-Cu laser and inhibit arc formation in the discharge.