Abstract: Filled composite compositions can be used as encapsulants, underfill materials, and potting materials in electronic and optical packages that are subjected to a wide temperature range. The composites contain a matrix and a filler composition. In a preferred embodiment, the matrix is an organic material. The filler composition contains particles of a material that have a negative coefficient of thermal expansion. The filler composition contains particles having a wide range of sizes. Furthermore, the particles exhibit a non-normal, for example, log normal or power-law, particle distribution. The non-normal size distribution of the particles enables the filler composition to be formulated at high levels into organic matrices, resulting in composites that have very low coefficient of thermal expansion to match those of the semiconductor materials in the electronic package or optical components in an optical assembly.

Abstract: A spacecraft (10) having a cryogenic cooler (24) that maintains different temperatures in thermally insulated and nested enclosures (26, 28, 12). In the coldest enclosure (26), which is maintained, for example, approximately 10.degree. K, low-temperature superconducting (LTS) processors (32, 34) perform bus and payload processing functions at very high speed. The next-coldest enclosure (28) is maintained at approximately 77.degree. K and houses high-temperature superconducting (HTS) electronic modules, such as for power regulation and distribution (40) and a payload sensor processing module (38). The third of the enclosures (12) is maintained at approximately 300.degree. K and houses other modules operating at room temperature, including a transponder (44), power control (46), energy storage (48), a propulsion subsystem (22), a downlink data processing module (49) and the cryogenic cooler (24) itself.

Abstract: A two-dimensional integrated laser array having a plurality of surface-emitting laser arrays and a plurality of waveguides for optically coupling the individual laser arrays together. Each surface-emitting laser array includes a plurality of injection lasers which are evanescently coupled together in order to emit a single beam of light. The coupling provided by the waveguides causes the surface-emitting laser arrays to operate in phase and at the same wavelength as an external master oscillator. Therefore, the surface-emitting laser arrays generate coherent beams of light, which are combined and focused by a micro-lens. The output of the micro-lens is a single, coherent high-power optical beam which is emitted perpendicular to the two-dimensional integrated laser array.

Abstract: A semiconductor diode structure including a light-absorbing substrate, an active region, and a pair of cladding layers surrounding the active region. Lasing is inhibited by means of an inclined end facet, which reflects light down into the substrate, where it is absorbed, to provide only one pass of the spontaneously emitted light through the active region. One disclosed embodiment has a conventional end facet for the out-coupling of edge-emitted light. Another embodiment includes a surface-emitting facet formed in an opening in the substrate adjacent to the inclined facet. Yet another embodiment has two inclined facets. One inclined facet may serve to reflect light into the absorbing substrate, or both may serve to reflect light through separate surface emitting facets.

Abstract: An improved heat transfer device particularly suited for use as an evaporator plate in a diffusion cloud chamber. The device is characterized by a pair of mutually spaced heat transfer plates, each being of a planar configuration, having a pair of opposed surfaces defining therebetween a heat pipe chamber. Within the heat pipe chamber, in contiguous relation with the pair of opposed surfaces, there is disposed a pair of heat pipe wicks supported in a mutually spaced relationship by a foraminous spacer of a planar configuration. A wick including a foraminous layer is contiguously related to the external surfaces of the heat transfer plates for uniformly wetting these surfaces.