A gas-discharge laser having a Brewster window near at least one of the reflectors which is secured directly to the laser tube. The Brewster window is secured to a surface of the laser tube and a normal to the window makes an angle equal to the Brewster angle with the axis of the laser tube. The surface may be a slot in the laser tube or a recessed end face of the laser tube near a reflector. An advantage is that the Brewster window may have any convenient diameter and that the laser tube need not be drilled to form a cavity.
4426708 - Laser device - Owned by Stichting Research en Techniek van de Katholieke Universiteit (NL)
Laser device comprising a tube for gaseous or vaporous laser material, which tube is sealed at both ends by a window consisting of a plate of radiation-transmissive material. Each window plate rests directly on the associated end face of the tube and is held against this end face by a retaining frame surrounding the window plate and secured to the end face of the tube. The retaining frame has its surface remote from the end face provided with a flange extending inwardly to overlie the periphery of the window plate and has its surface facing the end face provided with a recess located at its inner edge surrounding the side edge of the window plate. An O-ring is received in the recess.