摘要 |
By surrounding a gas discharge laser, which comprises a cylindrical glass envelope provided at two ends with laser mirrors which together constitute an optical resonator, at least partly and substantially coaxially with a sheath which is secured around the envelope by means of very slack resilient elements, for example rubber blocks or metal springs, varying temperature gradients in the envelope as a result of the gas discharge are substantially prevented so that the initial alignment of the laser beam does not vary substantially.
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