Abstract: An adjustment device for adjusting the reflector mirrors of a laser resonator to be precisely parallel to one another comprises a carrier and an integral adjustment head together having an H-cross section provided by a recess system of a peripheral outer recess flanked by a pair of inner circular recesses so that an axially elastic and adequately side stable and temperature permanent adjustment derives.

Abstract: For easy durable and safe fastening of an optical element (2) (e.g.: a reflector-mirror), without affecting ambient cleanliness, a cup-shaped frame (1) is provided, in whose depressed hollowed-out area (6) the optical element is embraced and thus laterally secured, while a spring leg (3) is provided as a fixing element, exerting a compressional force on the optical element. In this way, a threadless, cementless/plasterless fastening is realized. The invention is generally suitable for fastening optical elements, particularly a mirror or a totally reflecting prism of an optical resonator.