Abstract: A preferred embodiment of a composite mirror comprises (1) a substrate of carbon-carbon, (2) intermediate layers of silicon carbide, silicon dioxide, (3) optically polished layers of metals and/or suitable glass (ultralow-expansion or modified fused-silica glass) and (4) an optical coating of high reflectivity. The resulting mirror exhibits desired features including high optical quality and a low coefficient of thermal expansion; such mirrors being well suited to high thermal flux applications. Methods of producing the composite mirror are described.

Abstract: A method of molding glass elements requiring no further preparatory operations such as grinding or polishing before use wherein a portion of glass is heat-softened and subjected to pressure in a mold having molding surfaces formed of a material comprising a mixture of silicon carbide (SiC) and carbon.

Abstract: A zoom projection lens having six elements with a second biconcave negative element being movable for zooming. Five of the six elements are made of plastic materials and the use of aspheres on two surfaces, including one surface of the movable element, is disclosed to achieve good optical performance at a relative aperture of at least f/1.57.