Abstract: Superconducting copper oxides of the perovskite structure are modified to have mixed occupancy of a cation site, thereby resulting in increased limits in critical field and/or critical current. Mixed occupancy may be observed in terms of increased resistivity as the superconducting material reverts to a nonsuperconducting state. A significant advantage, at least for preferred compositions, derives from the fact that critical temperature is unaffected relative to the prototypical material.

Abstract: Remote positioning to submicron accuracy is based on comparison of two interference gratings, the first of constant phase, and the second segmented. Positioning corresponds with equal segment-by-segment overlap of an image of one grating superimposed on the other.

Abstract: Fabrication of integrated circuits--electronic, photonic or hydrid--permits attainment of higher device density. Pattern delineation with smaller design rules than previously associated with delineating radiation of given wavelength is the consequence of use of phase masks. Compared with earlier used, binary valued phase masks, the multiple values of those on which this fabrication depends permits improved effectiveness in lessening of edge-smearing radiation of consequence (of diffraction-scattered delineating radiation at feature edges). Phase masking may provide, as well, for feature generation by interference, and for reduced intensity of unwanted image hot spots by diffraction.

Abstract: Expedient fabrication of phase masks providing for many values of phase delay for exiting pattern delineating radiation depends upon a two-step procedure. Such masks offer improvement in ultimate device fabrication relative to that offered by prior binary-valued masks. In the first step, which may be carried out coincident with introduction of device feature information, apertures of appropriate size and distribution are produced in the relevant mask layer; in the second step material surrounding such apertures is heated to result in backflow-filling. The consequential layer thinning is such as to introduce the desired local change in phase delay.

Abstract: Reduction of laser threshold in an electrically pumped vertical cavity laser is the consequence of interpositioning of an electrode layer intermediate the active, photon producing region, and at least one of the two Distributed Bragg Reflectors defining the laser cavity. The advance is a consequence of the lowered pump circuit resistance due to elimination of one or both DBRs--in particular, to elimination of the p-doped DBR--from the pump circuit.

Abstract: High carrier concentration, as well as abrupt change in such concentration in GaAs-based devices, is the consequence of selection of tin dopant-containing precursor compounds as used during layer growth. Alkyl tin compounds, as used during MetalOrganic Molecular Beam Epitaxy, are of particular value in the growth of pnp heterojunction bipolar transistors, likely in conjunction with other devices in large scale integrated circuits.

Abstract: Lead inclusion in copper-containing wrought alloys is coming into disfavor due to health and environmental considerations. Machinability, as well as retention of workability properties, associated with lead inclusion are assured by bismuth together with a modifying element, phosphorous, indium or tin, with such modifying element minimizes the workability-precluding embrittlement otherwise associated with bismuth. Fabrication of product dependent upon properties of the large variety of lead-containing alloys is so permitted by use of lead-free material.

Abstract: Optical integrated circuitry, performing various of the functions associated with electronic integrated circuitry, is disclosed. Fabrication, importantly to achieve high circuit chip density--typically in the range of 10.sup.6 as including both devices and interconnecting guides--is dependent upon device/spacing dimension miniaturization resulting from fabrication in very thin layers. Typical layer thickness as retained in fabricated devices and guides, of a maximum of the order of a 1/2 wavelength for relevant photon flux, results in limitation in cross-talk to permit device design rules of one or a few wavelengths.

Abstract: Fabrication of devices of micron and submicron minimum feature size is accomplished by lithographic processing involving a back focal plane filter. A particularly important fabrication approach depends upon mask patterns which produce images based on discrimination as between scattered and unscattered radiation by accelerated electrons.

Abstract: Top surface emitting, vertical cavity, surface emitting lasers depend upon emission through apertured top surface electrodes. Biasing current, accordingly peripheral to the laser as introduced, follows a path which comes to confluence within the active gain region to effectively attain lasing threshold. The path is consequence of a buried region of increased resistance which encircles the laser at or above the active region. The buried region is produced by ion implantation-induced damage with ion energy magnitude and spectrum chosen to produce an appropriate resistance gradient. Integrated, as well as discrete, lasers are contemplated.

Abstract: Information processing, for example by means of a computer, is served by a tablet in combination with an inputting implement such as stylus or human finger. Such a tablet-implement combination may serve in lieu of or ancillary to other inputting means such as a keyboard. Implement positional information, e.g., as contacting the tablet, depends upon interpolation as between segmenting lines in the tablet. Cost advantage commensurate with resolution/noise desiderata is ascribable to use of analog information (without digitization) in interpolation.

Abstract: Fine featured devices are produced by a series of fabrication steps including exposing selective surface regions to irradiation, e.g. to an ion beam, generally to result in removal of masking material within irradiated regions. In most instances, subsequent etching is under conditions such that bared material is preferentially removed. Etch-removal and irradiation are such that overgrown material is of device quality at least in etched regions. The inventive process is of particular value in the fabrication of integrated circuits, e.g. circuits performing electronic and/or optical functions. The inventive process is expediently used in the fabrication of structures having minimum feature size of 1 micrometer and smaller. Patterning is dependent upon masking material of a maximum thickness of 100 .ANG..

Abstract: Fabrication of devices of micron and submicron minimum feature size is accomplished by lithographic processing involving a back focal plane filter. A particularly important fabrication approach depends upon mask patterns which produce images based on descrimination as between scattered and unscattered radiation.

Abstract: Distributed feedback mirror cavities are found capable of sufficient reflectance-loss characteristics to permit lasing in two or a single quantum well structure in which lasing is in the thin (quantum) dimension. Such lasers sometimes known as "quantum well surface emitting lasers" are of sufficiently low threshold value as to permit use in integrated circuits of high integration density--e.g. at 1 micron design rules. Anticipated uses, now made possible, include optical circuitry for computer chip interconnect as well as optoelectric integrated circuits for many purposes including computing itself.

Abstract: An electrically pumped vertical cavity laser depends upon reflection as between an unaided DBR reflector on one side of the cavity and a metal-supplemented DBR reflector on the other. Placement of the shorter supplemented DBR on the p-conductivity type side of the cavity reduces the resistance of the electrical series pump path. Permitted use of an active region of a thickness of 1 .mu.m or less in the lasing direction results in low lasing threshold. The structural approach is of significance for laser integration in integrated circuits, whether electro-optic or all-optic.

Abstract: Photovoltaic generation of voltages well above the bandgap results upon absorption of radiation by a dipolar dopant within a transparent polarized pyroelectric body. Generation is by a charge transfer mechanism in accordance with which electrons are transferred from excited absorbing species. A photovoltage of greater than a thousand volts has been observed in Fe.sup.2.sup.+ -doped LiNbO.sub.3.

Abstract: Fluorimetric assay procedures indicative of the presence of antigens or other abnormal conditions in body fluids permit rapid, accurate screening. Extra-clinical testing is facilitated by a fluorimeter design providing for optical excitation of a totally absorbing sample and for fluorescence being detected in a direction which avoids sensing of simple reflected excitation energy. An exemplary procedure in which the sample is a drop of unprocessed blood screens for lead intoxication and iron deficiency anemia.

Abstract: The condensation product of oxalyl dihydrazide and a mono-ortho-hydroxy aryl ketone is found to be an effective metal deactivator in saturated hydrocarbon polymers. The stabilizer is usefully incorporated in primary insulation, for example in polyethylene insulation on copper wire.

Abstract: Members of a particular class of magnetic garnet compositions show characteristics useful for incorporation in magnetic memory devices which depend for their operation on the positioning of single wall domains ("bubbles"). Such compositions, ordinarily in the form of a supported layer, manifest high limiting bubble velocity, thereby making possible high record and access rates. Tetrahedral iron sites in the concerned compositions are occupied by non-magnetic ions in amount such as to result in magnetically balanced iron sub-lattices so that the magnetic moment contribution is made primarily by dodecahedral site ions. Europium is a necessary dodecahedral site occupant. High limiting velocity is attributed to the high value of the gyromagnetic ratio (g value) associated with europium.

Abstract: A light guide is produced by the out-diffusion of boron oxide through a free surface of a uniform borosilicate mass. The resulting structure consists of increased index silica rich regions near the surface in contact with lower index regions of a composition approaching that of the unmodified borosilicate. The out-diffusion process, generally carried out at a temperature approaching the softening point of the glass, may be applied to a borosilicate tube to result in a fiber preform. Fibers drawn from such a preform may be characterized by a silica core region, a borosilicate clad region, and a silica outer shell. Use of the procedure results in a graded index structure.