GASLASER

An internal mirror metal vapor laser, and in particular, a helium-cadmium laser discharge tube, which is economical, compact and has a relatively long operating and shelf life, typically of 10,000 hours. A positive column helium-cadmium laser tube of the consumable type and having optical resonator mirrors integral with the tube ends to hermetically seal the tube is provided which includes a relatively large volume cadmium reservoir capable of containing sufficient cadmium for life times exceeding ten thousand hours. A resistive heater is applied to the cadmium reservoir for controlling the cadmium vapor pressure. A heat sunk diffusion confinement section and a cataphoretic confinement section are provided adjacent one end mirror and a heat sunk diffusion confinement section is provided adjacent the other end mirror to protect the end mirrors from condensing cadmium vapor. The laser tube includes a high pressure, permeable implant member which contains helium under pressure and which is utilized to compensate for helium pressure loss in the laser discharge tube to substantially extend the life time of the discharge tube.