Abstract: Yttrium aluminum garnet is employed as a light-transmissive window for electro-optic device packages. This material is resistant to high amounts of atomic radiation.

Abstract: A technique for positioning a body having a tapered profile when viewed along a first axis comprises exposing the body to a first beam of light oriented along the first axis in a manner such that the tapered profile is projected as a first image onto a first linear array of photodectors disposed along a direction orthogonal to both the first axis and the direction of the taper. The body is exposed to a second beam of light oriented along a second axis orthogonal to the first axis in a manner such that a second profile of the body is projected as a second image onto a second linear array of photodetectors disposed along a direction parallel to the first axis. The body is then moved along the first and the second axes until the first and the second images strike predetermined locations along the first and second photodetector arrays.

Abstract: A method for machining a workpiece with a beam of radiant energy in the presence of a chemically-reactive gas characterized in that (a) the beam heats the area of incidence of the workpiece to a reaction temperature that is below the melting point of the workpiece material and (b) the chemical reaction is exothermic and produces a reaction product having a boiling point that is below the reaction temperature of the workpiece material. The gas is preferably a halogen or nonmetallic halide which reacts with the workpiece material to produce a metal halide.