Abstract: An apparatus and a method for texturing blended synthetic multifilament yarns, wherein the blended yarns are each produced in parallel from a plurality of individual yarn components. The individual yarn components are withdrawn and drawn by a withdrawal means, with a guide means being associated to the withdrawal means for combining the individual yarns to the blended yarns. The blended yarns are separately textured, and to obtain for each of the blended yarns a combination of the individual yarn components that is as identical as possible, the individual yarn components are divided into groups, with each group being reciprocated by one of a plurality of individually controlled traversing yarn guides. The groups of the individual yarn components are guided independently of one another while being reciprocated, with each of the individual yarn components per group being respectively associated to the blended yarns.

Abstract: An apparatus and a method for texturing blended synthetic multifilament yarns, wherein the blended yarns are each produced in parallel from a plurality of individual yarn components. The individual yarn components are withdrawn and drawn by a withdrawal means, with a guide means being associated to the withdrawal means for combining the individual yarns to the blended yarns. The blended yarns are separately textured, and to obtain for each of the blended yarns a combination of the individual yarn components that is as identical as possible, the individual yarn components are divided into groups, with each group being reciprocated by one of a plurality of individually controlled traversing yarn guides. The groups of the individual yarn components are guided independently of one another while being reciprocated, with each of the individual yarn components per group being respectively associated to the blended yarns.

Abstract: A diffractive and a refractive microlens component are combined into a doublet lens to obtain imaging properties that are improvements over those achievable using separate components. In one application, diffractive/refractive microlens arrays are arranged to provide a free-space optical permutation interconnect arrangement.

Abstract: A reduced-blocking system where a perfect shuffle equivalent network having a plurality of node stages successively interconnected by link stages, is advantageously combined with expansion before the node stages and/or concentration after the node stages in a manner allowing the design of a system with arbitrarily low or zero blocking probability. An illustrative photonic system implementation uses free-space optical apparatus to effect a low loss, crossover interconnection of two-dimensional arrays of switching nodes comprising, for example, symmetric self electro-optic effect devices (S-SEEDs). Several low loss beam conbination techniques are used to direct multiple arrays of beams to an S-SEED array, and to redirect a reflected output beam array to a subsequent node stage.

Abstract: Alignment difficulties in optical computing arrangements are overcome by integrating the optical components on a single substrate and arranging the elements in a manner that causes them to interact with one another to perform the desired function. The substrate has one or two major surfaces and the elements are grown or fabricated on those surfaces using conventional integrated circuit manufacturing techniques. Most advantageously, the position-sensitive optical devices are manufactured on one side. Reflective planar optical devices are obtained by applying a reflective layer over the fabricated planar optical devices.

Abstract: A crossover network implemented using two-dimensional arrays of nodes. The network is a perfect shuffle equivalent network because it is topologically equivalent to a crossover network of one-dimensional arrays of nodes. The two-dimensional arrays are arranged in rows and columns and there are a plurality of link stages interconnecting successive arrays. The network is implemented efficiently in free space optics because the network topology requires optical crossovers in some link stages that interconnect only nodes in the same column of successive arrays and optical crossovers in the other link stages that interconnect only nodes in the same row of successive arrays.

Abstract: A facsimile optical apparatus that comprises an optical head includes planar integrated optics. The head is fabricated with planar reflective lenses situated to focus light onto an image surface, and an array of planar reflective lenses to focus light reflected off the image surface onto an array of light detectors. Optionally, the light generating and the light detecting elements are fabricated on the substrate containing the planar reflective lenses, resulting thereby in a very compact arrangement. When image lines need to be accepted that are larger than the size of arrays that can economically be fabricated on a single substrate, integrated aligning means are provided to couple a number of substrates to each other and to form thereby a larger working element.

Abstract: Alignment difficulties in optical computing arrangements are overcome by integrating a number of the optical components on a single substrate and arranging the elements in a manner that causes them to interact with one another to perform the desired functions, such as image manipulations. the substrate has one or two major surfaces and the elements are fabricated on those surfaces using conventional integrated circuit manufacturing techniques. Most advantageously, the position-sensitive optical device are manufactured on one side of the substrate, obviating the need to align two masks during the manufacturing process.

Abstract: Alignment difficulties in optical computing arrangements are overcome by integrating the optical components on a single substrate and arranging the elements in a manner that causes them to interact with one another to perform the desired function. The substrate has one or two major surfaces and the elements are grown or fabricated on those surfaces using conventional integrated circuit manufacturing techniques. Recognizing that an optical circuit can be larger than what can be fabricated on a single substrate, aligning structures are fabricated onto substrates that need to be coupled to form the optical circuit. The aligning structures contain registrable protrusion and indentation portions, such as ridges and grooves, that are imbedded into the substrates as part of the manufacturing process of the optical elements. Most advantageously, the position-sensitive optical devices are manufactured on one side.

Abstract: A crossover network is obtained by using a plurality of similar optical crossover stages. Each stage includes two light paths that combine at an output plane. One path provides the direct connection while the other path provides the crossover connection. To realize this crossover capability, each stage comprises a beam splitter element that accepts a beam containing an image array and develops therefrom two beams that are each directed in two different paths. Along one path, means are provided for reversal of selected segments of the image array and for sending of the reversed or crossed-over image through a beam combiner. Along the second path, means are provided for applying the light to a beam combiner without the image reversal. One disclosed means for image reversal is a prismatic mirror. The number of corners in such a mirror differs from stage to stage.

Abstract: A novel method of sintering Si.sub.3 N.sub.4 shaped bodies which method comprises grinding Si.sub.3 N.sub.4 with the use of a grinding material down to a surface area magnitude of 10.5 to 35 m.sup.2 /g and an average particle size from 0.2 to 0.005 .mu.m, shaping the powder obtained, and sintering the compact under inert gas or nitrogen at a temperature from 1700.degree. to 1900.degree. C.

Abstract: In a process for the production of dispersion ceramics by sintering or hot pressing of a mixture of a matrix-forming ceramic material and of at least one ceramic embedment material dispersible therein which at the sintering temperature of the ceramic and at room temperature is present in different enantiotropic solid modifications of different densities, a ceramic embedment material is employed which is divided into at least two groups of different, substantially uniform particle sizes, each group having different lower phase-transition temperatures.