A gas discharge laser including at least one electrode consisting of a rolled metal foil which is clamped in the tubular envelope of the laser. Spacers are provided between the foil and the inner wall of the envelope at regular distances from each other and may consist, inter alia, of pits depressed in the metal foil so that a rotationally symmetrical heat transfer from the electrode to the envelope is obtained. A thermally stable laser thus is obtained in which the generated laser beam has a substantially constant direction.

A gas laser housing having a housing and a metal cap attached thereto, includes a mirror mount attached to the metal cap. The mirror mount is provided with an annular region of reduced diameter affixed to the metal cap to absorb mechanical stresses and thereby prevents stress crack corrosion at the circumference of the housing tube.

In a coaxially constructed gas laser with a capillary fused at one end to the glass casing surrounding it and enclosed at its free end by a supporting spring the supporting spring contains a perforated disc of a material adapted thermally to the jacket glass and is framed by a shrunk-on jacket constriction. Such a mount is extraordinarily stable mechanically and thermally. In a preferred embodiment the supporting spring is a multipart spring: attached to the thermally adapted perforated disc are two other, smaller perforated discs consisting of a spring material of temperature constancy and containing the actual spring elements.

A capillary bore laser tube is constructed to have little or no power loss when subjected to relatively high shock loads during operation. A spider structure supports the free end of the capillary bore tube in an almost rigid manner against transverse movement of the free end with respect to the outer envelope or jacket of the laser tube so that high shock loads and vibration produce little or no permanent change in the radial alignment of the free end of the bore tube with respect to the other operating components of the laser tube. The spider structure is a disk shaped member which is rigidly attached at its outer periphery to the outer envelope and which is also rigidly attached at its inner periphery to the bore tube. The spider structure is sufficiently flexible in a longitudinal direction to accommodate differential thermal expansion resulting from the differences in temperatures between the bore tube and the outer envelope produced when the laser is energized for operation.

The laser is an internal mirror hermetically sealed design, utilizing an envelope made principally of glass. The effects of thermally produced distortion on mirror alignment are minimized by providing a thermally and electrically conductive liner in close contact with the envelope wall. Misalignment of the discharge-confining capillary tube is minimized by supporting its inner end by means of a concentric stiff but resilient spring, thus avoiding an unsupported cantilevered section of the capillary. Reliable starting even in environments where the ambient electromagnetic radiation is inadequate for gas ionization is secured by providing a radioactive source in the region of the anode electrode.