Abstract: An improved remote speed sensing technique is described which improves performance reliability by increasing the relative signal to noise ratio of a speed detector compared to that of a vehicle radar detector, by localizing at least one axis of the illuminating radiation to an angular region which is comparable to or within the subtence of the target vehicle, while minimizing illumination of a radar detector on the target vehicle.

Abstract: A phase change material cooled mirror arrangement includes a mirror substrate which has a reflective front major surface and a rear major surface. The mirror is cooled by advancing at least one rod of a solid phase change material toward the rear major surface of the mirror substrate for gradual melting of the material at the rear major surface by heat absorbed from the substrate with attendant cooling of the latter, at an advancement speed sufficient for the solid phase change material to make up for the amount of such material that has been transformed into liquid by the melting thereof. The liquid phase change material is then removed from the vicinity of the substrate and possibly resolidified and added to the trailing end of the rod in a recirculating system.

Abstract: A phase change material cooled mirror arrangement includes a mirror substrate which has a reflective front major surface and a rear major surface. The mirror is cooled by advancing at least one rod of a solid phase change material toward the rear major surface of the mirror substrate for gradual melting of the material at the rear major surface by heat absorbed from the substrate with attendant cooling of the latter, at an advancement speed sufficient for the solid phase change material to make up for the amount of such material that has been transformed into liquid by the melting thereof. The liquid phase change material is then removed from the vicinity of the substrate and possibly resolidified and added to the trailing end of the rod in a recirculating system.

Abstract: A window for use with high energy laser (HEL) systems utilizes a combination of window and cooled mirror technologies. The present window is adapted to receive an elongated focus beam at one or more adjacent diamond plates. The plates are positioned in base members by peripheral edges thereof. Heat generated by the absorption of radiation from the beam is transferred directly to heat exchangers in the base members through the peripheral edges. The geometry of the window ensures that heat transfer is bidirectional. The very short distance the heat must travel results in a very small rise in temperature of the window with a correspondingly small amount of optical distortion.

Abstract: A thermal distortion effect compensated mirror includes a mirror substrate having a reflective surface, and a compensating layer on the reflective surface. The compensating layer is of a material that is substantially transparent to a laser beam to be reflected by the mirror, and has such a thickness as to substantially compensate, during the passage of the laser beam therethrough, for the differences in the propagation path lengths of different laser beam regions impinging on and reflected from different portions of the reflective surface that have been displaced to different extents from their original positions by different thermal growths of the respective underlying zones of the substrate owing to different heating of such substrate zones by different energy levels of the associated laser beam regions.

Abstract: A composite structure including fibers embedded in a silica glass matrix is made by first forming a precursor of the structure by embedding the fibers in a matrix of a silica-based glass material which further includes a glass-forming additive that lowers the working temperature range of the material below that of pure silica glass, and by leaching the additive out of the glass matrix material. The thus obtained porous glass matrix may then be consoidated at an elevated temperature that is considerably lower than that which would be needed for manufacturing the glass matrix directly from a material having substantially the same composition as the material of the leached-out glass matrix.