One-piece, light-weight, transparent telescope mirror blanks consisting essentially of one integral shaped mass of transparent, low-expansion, at least partially crystallized glass ceramic having a pair of oppositely disposed face surfaces and a plurality of separate cavities between the face surfaces. One of the face surfaces of the mirror blank has a plurality of openings therein, each of the openings being in communication with a cavity. The cross-sectional area of the opening is smaller than the cross-sectional area of the cavity. Telescope mirrors can be made by coating the surface of the mirror blank with an appropriate reflecting coating. Methods of making the mirror blank and mirror are also disclosed as well as apparatus.
This application is a division of copending application Ser. No. 862,122, filed Aug. 5, 1969, which in turn is a division of copending application Ser. No. 468,691, filed July 1, 1965, now U.S. Pat. No. 3,484,328, which in turn is a continuation-in-part of application Ser. No. 437,431, filed Mar. 5, 1965, now abandoned.
The mirror is constructed having a reflecting surface formed on a heat exchanger plate means having a manifold on each end. The free ends of the manifolds are connected by rod members. The plate means is bonded to the top of a rigid backing member and the bottom of the backing member is bonded at three points to a mounting pad member which in turn is mounted to a mount block by an alignment assembly at three locations. Each alignment assembly has interacting spherical and conical shaped members for facilitating installation. The mount block has three locations for receiving said assemblies, one location being rigid while the other two are located on flexible arms permitting a limited amount of movement to prevent an undue force being transmitted between the mount block and the backing member. The mount block is maintained on a foundation by a large bolt through the center thereof.
A laser mirror is constructed to provide a reflecting surface having a minimum amount of distortion while it is reflecting a high-power high-quality laser beam. The mirror is constructed having a backing plate made of a vitreous ceramic which has a very low coefficient of thermal expansion and a stiffness comparable to many metals. The reflecting surface is formed on a heat exchanger plate means which is bonded to said vitreous ceramic and has a manifold on each end. A coolant is passed through said heat exchanger plate means to reduce internal thermal response. The heat exchanger plate means can be formed from two preformed metal plates or one metal plate with a second plate being formed by plating. The invention herein described was made in the course of or under a contract or subcontract thereunder with the Department of the Air Force.
The alignment device (10) is used for aligning an optical transmitting beam with an optical receiving beam. It comprises a rough alignment device and a fine alignment device. The rough alignment device has a first mirror (30.1), which can be rotated by approximately 360.degree. around a first axis (14), in respect to which the first mirror (30.1) is set at 45.degree. to the first axis. The rough alignment device furthermore has a second mirror (32.1), which can be rotated by approximately 180.degree. around a second axis (16), in respect to which the second mirror (32.1) is set at 45.degree.to the second axis. The second axis (16) can be rotated around the first axis (14), so that the second mirror (32.1) can be rotated within a spatial angle of approximately one hemisphere by the cumulative rotations around the axes (14, 16). The fine alignment device is constituted by a tiltable seating device (30.6 to 30.17) for at least one mirror (30.1), by means of which this mirror (30.1) is tiltably seated. The fine alignment device furthermore has an actuator device (30.18 to 30.19), by means of which the mirror (30.1) can be tilted in relation to its center normal line (15) within a spatial angle, which is considerably less than the hemisphere. At least the tiltably fastened one of the two mirrors (30.1, 32.1) is embodied with reduced mass.
A chopped fiber reinforced glass or glass-ceramic matrix integral stgructure having no bond lines. The structure comprises a face plate, a back plate, and a grid array of chamber walls. The face plate connects to the back plate through the chamber walls forming a grid array of chambers. The back plate has an array of apertures that lead to the chambers. The structure is fabricated by disposing at least two mold inserts in a mold housing having a bottom and sides. The mold inserts are in contact and in an array that follows the surface contours of the mold. The mold inserts and mold insert array is not capable of lateral movement. Heated chopped glass or glass ceramic impregnated fibers are displaced into the mold under pressure to form a composite. The composite is cooled and the mold inserts are removed by chemical dissolution.
A method for constructing a mirror blank, including arranging hollow glass balls, on a front face sheet, and in close proximity to each other to permit fusing upon expansion; restricting the expansion of the hollow glass balls with a bounding structure during expansion of the hollow glass balls to force the hollow glass balls into a densely packed array of cells; applying heat to soften the hollow glass balls and increase the pressure within the hollow glass balls as the hollow glass balls fuse with each other during expansion, forming cells, wherein as a result of fusing, the hollow glass balls contact the front face sheet as a result of the increased pressure within the hollow glass balls; annealing and cooling the mirror blank to below annealing temperature associated with the hollow glass balls; and venting the cells.
