Abstract: A method is shown to make a relatively thick foraminous plate wherein the inside of each one of the foramina is treated as desired, the disclosed method comprising the steps of working a strip of a metallic or plastic foil to form transverse grooves, treating the worked strip to cause the surfaces of such grooves to have desired qualities and then rolling the strip (or stacking portions thereof) to form the desired foraminous plate.

Abstract: An antitank weapon system is shown to include a projectile carrying at least one pulsed laser radar which periodically illuminates swaths of the underlying terrain, means for processing return signals to distinguish between the radar signatures of objects on such terrain and means for firing submunitions to impact on any object whose radar signature corresponds to that of a tank or other desired target.

Abstract: Various embodiments of optical apparatus incorporating a foraminous plate to define a field of view are disclosed. In a first embodiment, the foramina in a foraminous plate are cylindrical with the field of view defined by the ratio of the diameter of each foramen to the thickness of the foraminous plate. The presence, or absence, of a target within the field of view is determined by the electrical signal out of a photodetector actuated by light passing through the foramina. In particular, embodiments illustrating the use of the disclosed optical apparatus as a sensor in a guided missile, the foraminous plate and photodetector are movably mounted in such a missile to allow either bearing or range of a target to be determined.

Abstract: An optical interferometer for use in observing the optical quality of a relatively large area of a mirror of any shape is disclosed. The disclosed interferometer comprises an arrangement for splitting a beam from a light source into two beams and focusing the two beams on appropriately shaped slits to derive two coherent sources and then directing the light from such sources through conjugate paths (one of which includes a mirror whose surface is to be checked) to a viewing screen. The interference pattern observed on such screen then is determined by the optical quality of the illuminated portion of the mirror being checked.

Abstract: A mirror, and method of making same, is disclosed. The mirror includes a metallic base material having a low coefficient of thermal expansion, an intermediate layer bonded to the base by a plasma spray process and a reflecting surface overlying the intermediate layer, the coefficients of thermal expansion of the materials of the intermediate layer and the reflecting surface differing from each other and from the coefficient of thermal expansion of the base material.

Abstract: Catoptric lens arrangements for combining energy from a number of sources, as optical energy from a number of lasers, are shown. The disclosed arrangements include sets of mirrors with reflecting surfaces sharing focal points spaced from a common axis. The mirrors in each one of the sets are disposed on a common mount in such a manner that aperture blockage is completely eliminated.

Abstract: Different species of catoptric lens arrangements are shown, each one of the disclosed species being characterized by use of a quadratic conic mirror having real or virtual focal points displaced from a lens axis. With a quadratic conic mirror having such a characteristic, the image points of axial, or paraxial, rays are similarly displaced so that aperture blockage may be eliminated and achromatic aberrations may be reduced to such an extent as to make the lens arrangement diffraction limited.

Abstract: An improved laser particularly well adapted to produce high flux densities is disclosed. The disclosed laser includes an optical cavity wherein a curved window and a convex mirror make up one end wall assembly, such window and mirror being disposed with respect to each other in such a manner that the flux density at the window is less than the flux density at the mirror and, at the same time, energy reflected from the window constructively interferes with energy within the optical cavity.

Abstract: Catoptric arrangements for steering a laser beam by moving one, or more, mirrors relative to two substantially orthogonal axis of rotation are shown. In the various embodiments illustrated, one of such axes of rotation, around which all of the mirrors in each embodiment are rotatable, is coincident with the longitudinal axis of the laser beam to be steered so as to direct such longitudinal axis toward different points on a first focal circle. Means are provided to rotate all of the mirrors in each embodiment, except the mirror irradiated by the laser beam to be steered, around the second axis of rotation to direct the longitudinal axis of such beam toward different points on a second focal circle substantially orthogonal to the first focal circle. Also shown are exemplary modifications to position the mirrors within each arrangement to aim the steered beam to points adjacent to the first and second focal circles.

Abstract: Improved catoptric lens arrangements to form beams from the energy emitted by extended sources of wave propagated energy are disclosed. All embodiments utilize at least a pair of mirrors disposed along a common axis, one of such mirrors being convex and the other concave, the generatrices of the reflecting surfaces of such mirrors being curves with noncoincident focal points, such generatrices being always divergent. At least one source of wave propagated energy is disposed between such reflecting surfaces so that all of the wave propagated energy from such a source is reflected back and forth between the mirrors in passing to an exit aperture defined by the mirrors.

Abstract: Improved catoptric lens arrangements to form beams from the energy emitted by extended sources of wave propagated energy are disclosed. All embodiments utilize at least a pair of mirrors disposed along a common axis, one of such mirrors being convex and the other concave, the generatrices of the reflecting surfaces of such mirrors being curves with coincident focal points, such generatrices being always divergent. At least one source of wave propagated energy is disposed between such reflecting surfaces so that all of the wave propagated energy from such a source is reflected back and forth between the mirrors in passing to an exit aperture defined by the mirrors.