Abstract: Quantum well lasers are herein made with purposely-graded interfaces which control the interdiffusion of atoms during high temperature processing. The result is a predictably-graded, large interface between the quantum well and the waveguide layers to either side thereof. The process is highly controllable and produces unique structures which exhibit surprisingly high power in a repeatable manner.

Abstract: Square cross section optical fibers are accurately positioned for coupling light from laser diode emitting facets through a fiber lens. The fibers are placed in parallel channels formed in a photolithographic layer on a planar surface of a substrate and constrained in place by a retention plate. The fibers extend beyond the retention plate unrestrained by photoresist but overlying the exposed portion of the planar surface of the substrate. The fibers over the exposed portion are cemented in place and the photoresist layer is then removed leaving the constrained portion of the fibers in very accurately defined positions, and free of epoxy cement, for abutment to the familiar fiber lens.

Abstract: An improved system for transmitting audio signals in a TV strewn employs an adaptive gain system. The system provides for sampling the audio signal in each of successive intervals in between 256 (2.sup.8) and 65,535 (2.sup.16) steps, for determining a reference voltage (i.e. maximum or mean, . . . ) amplitude for the interval, for dividing the signal into 256 steps, for providing a scaling factor for each of the steps which is a direct function of the reference voltage, and for transmitting the audio signal (interval) along with a code representative of the scaling factor to permit a receiver to faithfully reproduce the signal.

Abstract: Protection from current and voltage spikes is provided for a laser array by attaching a reverse diode laser array to shared contact pads before the first laser array is bonded to those pads. The arrangement provides for surge protection even during fabrication of the laser package where device failure results from power surges before surge protection circuitry is in place. Surge protection is afforded by having a reverse diode of the reverse diode array electrically in parallel with a corresponding laser diode of the protected array when activated.

Abstract: The cleavage of semiconductor crystalline wafers into laser diodes or laser diode bars is carried out at a low temperature at which both the semiconductor crystal substrate and the laser-forming laminate structure thereon are imbrittled. Cleavage at such low temperatures permits the cleavage planes to be closer together than was hitherto possible. A thickness to cavity length ratio of the resulting laser diodes or laser diode bars is approximately 1 as a result compared to 3/4 by prior art techniques. Also, the energy required for cleaving is reduced thus ensuring mirror surfaces at the cleavage planes.

Abstract: An array of laser diodes, or laser diode bars, is formed by positioning adjacent diodes or bars in an offset or staircase arrangement where the emitting facets of adjacent diodes, or bars, are in different planes. The offset arrangement permits the light from adjacent facets to be separated a distance q much shorter than permitted by prior art stacking arrangements because thermal and mechanical constraints characteristic of prior art stacks, are relaxed considerably in the offset arrangement. Power densities of 2000 watts/cm.sup.2 (cw) are achieved with spacings of 0.6 mm between adjacent laser bars, a ten fold increase in power density over in-plane (prior art) positioning of like components.

Abstract: A video projector employs an acousto-optic deflector for moving a horizontal line of pixels vertically to form an image on a remote screen. Because the pixel images are formed from parallel beams, rather than by reimaging a line of pixel images on a vertical deflector, the image formed is in focus at all screen distances. The horizontal line of pixels is formed from a single laser beam which is expanded laterally and passes through individual intensity modulators before being aimed at the vertical deflector. The horizontal line of beams may be divided into zones, one above the other, and later reorganized into a single line at the vertical deflector, in order to reduce the size of the projector.

Abstract: The array of recesses in a ball grid array carrier or (device) are populated with solder balls through a closely spaced tooling plate or stencil which has a like array of apertures. A solder bin is moved along side rails over the stencil allowing solder balls to fill the apertures in the stencil settling on the corresponding recesses and held there by adhesive. Excess solder balls are moved along by the movement of the bin. The bin is held in close contact with the stencil to avoid misplacement of the balls by bowing the stencil and by forcing it into a plane coplanar with the bottom of the bin. Alternative techniques are magnetic or vacuum areas of the bottom of the bin to ensure complete contact with the stencil.

Abstract: Power supplies which include sockets for supplying DC voltages as well as cables for supplying DC voltages to internal components of, for example, a computer are configured to prevent a user from connecting to an inappropriate DC voltage. The apparatus includes a special multiple din socket which provides a different voltage at each din of a subset of the dins, only one din of which is alive at a time. The apparatus includes a switch at each socket operative to select only a single din of a subset of dins at that socket. The illustrative apparatus includes several sockets, each one of which includes a different subset of dins selected by a switch, a single din at a time.

Abstract: An InGaAsP/AlGaAs/GaAs heterostructure laser diode includes an InGaAsP quantum well and at least a cladding region of AlGaAs while essentially avoiding the deleterious effects attributed to the presence of Al in heterostructure laser diodes. Embodiments with Al present in the cladding region and with Al present in both the waveguide and the cladding regions are described.

Abstract: Damaged automobile windshields are removed using an array of laser diodes. The diodes are chosen to provide light energy at a wavelength to be focused on and absorbed by the ceramic layer coating the windshield edge and to which is bonded the adhesive layer which holds the windshield in place. In practice, the diode array is moved along the windshield edge directing light through the windshield at the ceramic layer. The laser array comprises a linear array of diodes, having a length to span the width of the adhesive band.

Abstract: The placement of solder "balls" in a Ball Grid Array is accomplished by placing a solder strip in contact with the top surface of the ball grid array carrier. The pulsing of a laser directed at the solder in discrete positions permits the transfer of the solder to the gold dot, of the array of dots, on the carrier in registry with the laser output when activated. Selective solder placement is possible and increasingly higher throughput is achieved by the use of laser diode bars or optical fiber fans to effect solder transfer to a plurality of dots of the array simultaneously. The entire process can be automated by making the solder strip continuous through a recycling station arranged along a path along which the solder strip moves to the position where the carrier and the solder strip are moved into juxtaposition. The use of a transparent strip with a pattern of holes filled with solder paste permits easy transfer of the solder to the gold dots or islands on the carrier in registry with laser beam.

Abstract: A chemical-mechanical polishing apparatus includes a wafer carrier with a very low center of gravity which allows pressure to be applied evenly on a wafer being polished. The wafer carrier includes top, center, and bottom mating subassemblies with only the center and bottom subassembly or wafer holder actually rotating. The bottom of the central subassembly and the top of the bottom subassemblies are shaped as negative and positive, mating truncated pyramids with a downward extension at the center axis of the central subassembly which terminates in a ball in a recess in the top of the lower subassembly. The ball is positioned as low as possible to provide a very low center of gravity to ensure even pressure distribution over a wafer being polished. The truncated pyramidal shapes are to provide a geometry which exhibits a rigid structure with incrementally decreasing mass with distance from the central axis.

Abstract: Endpoint determination of a wafer removal process, in-situ, is afforded by the use of a Kalman filter known to be useful in celestial navigation. The use of line variable displacement transducers provides position error correction for the Kalman filter and the Preston equation provides the initial calibration for the endpoint determination. Accuracies of fifty angstrom are achieved.

Abstract: Chemical-mechanical polishing apparatus includes three subassemblies, a top subassembly which is non-rotating but which has a lower section which forms a shell about a center and a lower subassembly both of which rotate within the shell. The system also includes a slurry dispensing system which is embedded in the shell and which is operative to supply slurry just in front of the advancing edge of a wafer being polished by the system. The slurry dispensing system includes a tube with holes arranged 180 degrees about the shell of the non-rotating subassembly which is also operative to retain the wafer in contact with the (rotating) pad covered platen with which it is in contact.

Abstract: Electrical equipment such as a personal computer includes a plurality of internal components which require different voltages including low voltages of about five volts for operation. The different voltages are supplied by an internal power supply, with a voltage regulator, which is itself connected to an appropriately transformed high voltage supply typically from an in-the-wall source. Peripherals such as a FAX/modem, CD ROM, or tape recorder are powered by cables plugged into mating sockets in the face of the computer housing. The sockets, in turn, are connected to the appropriate outputs of the internal power supply to obtain appropriate voltage power directly from the host computer in the absence of a transformed connection to a house supply. A switch is provided at each of the sockets to vary the voltage there.

Abstract: Data generated and accumulated during a multi-stage proceeding, such as a litigation proceeding, is organized in a matrix of screens according to Section (catagory) and Level for later retrieval. Each screen is accessed by user selection of a point on the matrix and each screen has a pattern of fields at which data can be entered into the system. By imposing a pattern of fields of data entry, codes can be associated with each entry which permit ease of retrieval. Different subsets of the set of fields in the various screens have like codes to encode data entered there and to retrieve there subsets of stored data entered at other fields and having like codes. A data file is established for each case and a matrix is operative in a manner analogous to a template where a field is like an aperture in the template permitting access only to the data at the aperture.

Abstract: An improved fly forward converter including a capacitor connected across the collector and emitter of a switching transistor to form a parallel resonant circuit with the converter's transformer primary inductance, a diode across the switching transistor collector capacitor to conduct excess energy from the resonant circuit and coupling diodes in the converter's output circuit for coupling the energy in both the forward and flyback phases through an output inductor serially connected between the transformer secondary and the output capacitor. The converter includes a shunt capacitor with circuit values adjusted so that resonant action continues until the switching transistor voltage falls to zero for achieving "zero voltage switching". Zero voltage switching is achieved by varying the duration of the active cycle while the reset cycle duration is fixed and determined by resonant component value.

Abstract: Chemical-mechanical polishing apparatus includes a pad reconditioning mechanism which comprises nested conical tubes which overly the pad. The outer tube has an array of holes in it much like the head of an electric razor and is rotated about its axis by being in contact with the rotating pad. The inner cone is stationary and has a longitudinal, downward-facing slot. An air stream from the narrow end of the inner cone towards the wide end carries particle-laden slurry to the wide end for removal or recycling. The nested cones are arranged like a detachable bridge with the narrow end secured to a non-rotating center core and the wide end secured to the top of the table in which the (now annular) platen rotates.

Abstract: Apparatus for determining the luminous intensity distribution of an automotive head light employs a curved mirror and a curved screen. A solid state camera is used to obtain a pattern of the head light output from the screen. The system requires a relatively small black box into which the head light output is directed. A beam splitter may be employed to relax the constraints on the positioning of the various components within the box. The setting of the test lamp to first and to second preset lateral angular positions at each of which a pattern is captured and the combining of the two patterns permits the use of components which are practical. The use of a linear CCD array permits economies to be obtained by rotating the test lamp or by scanning the linear array over a sequence of angular positions and by constructing a composite pattern from the patterns so generated. In an alternative embodiment, no beam splitter is used.