An improved argon-ion gas laser utilizes a dispenser-type cathode and within the cathode shroud mounts a preignition electrode and a heat shield enabling the cathode to be operated efficiently and within a 900.degree.-1050.degree. C. temperature range over an extended period of time.
A laser employing a dispenser cathode is provided with a tubular enclosure surrounding that cathode. The tubular enclosure serves as a support for the bore and the optical chamber on either side of the dispenser cathode and is insulated from ambient temperature conditions by a ballast reservoir housed in a jacket encircling the tubular enclosure. The jacket has peripheral sidewalls spaced apart from the tubular enclosure. Lateral end walls connect the opposite extremities of the peripheral sidewalls in a sealing engagement to the exterior of the tubular enclosure. Communication between the interior of the jacket and the interior of the tubular support is afforded through an aperture formed in the tubular support at a location remote from the dispenser cathode. Leads for the dispenser cathode are disposed in a sealing engagement through the end walls of the jacket and enter the interior of the tubular support through the aperture formed therethrough. By retaining rather than dissipating from the tubular support the heat generated by the dispenser cathode, a predictable and circumferentially uniform amount of longitudinal, temperature-related dimensional changes are induced in the tubular support, preventing cathode housing bending of the support structure between the optical chamber and the bore. This contributes to enhanced mirror alignment stability.
A laser having a deflector in which bypass gas is separated from a cathode and the local discharge region around the cathode, and in which the bypass gas has a relatively long open passage around the deflector to the cathode. The deflector has an open end surrounding at least a portion of the cathode and an aperture and having an aperture and a raised shoulder connected to the end of a laser tube. The aperture is aligned with the discharge bore of the laser tube with gas bypass bores outside of the aperture enclosed by the shoulder. The anode end of the laser tube may also have a deflector which is an annular washer having an aperture and a raised shoulder. The washer has a diameter nearly as large as the anode in which it is mounted.
An electrode for pulsed gas lasers consisting substantially of tungsten and copper has a long life. With such an electrode contaminations of the laser gas and of the windows are largely obviated, even in long-time operation. An electrode suitable also for fluoride-containing laser gases consists essentially of an alloy containing copper, aluminium and nickel.
An ignitor for a preionizing means of an excimer laser has an electrically conductive core which projects into the gas space of the laser and which is surrounded by a jacket of a fluoroplastic. The jacket is brought into sealing engagement with the wall of the laser gas space by means of a pressure sleeve via mating conical surfaces.
