Abstract: A method of fusing together wafers (10, 30) or other semiconductor bodies comprising different semiconductors. In the case that wafers of InP and GaAs or other compound semiconductors are to be bonded, the wafers are cleaned with etchant, and their surfaces are placed together. While the wafers are forced together under moderate pressure and clean hydrogen flows over the wafers, the temperature is raised to 650.degree. C., close to the deposition temperature for epitaxial InP, and maintained for 30 minutes. In the case that one of the wafers is silicon (FIG. 5), both wafers are assembled together in hydrofluoric acid, in which the two wafers bond together by van der Waals force. Then, the assembly is placed in a furnace and annealed at 650.degree. C. A sharp hetero-interface (32, 66, 70) is produced with only surface defects which do not propagate into the bulk. Either wafer may be preformed with a multi-layer opto-electronic structure (12).

Abstract: An electrolyte resistant to oxidation normally resulting from high voltage charging of a secondary battery comprising a Li.sub.1+x Mn.sub.2 O.sub.4 intercalation positive electrode comprises a 0.5M to 2M solution of LiPF.sub.6 dissolved in a mixture of non-aqeuous dimethylcarbonate (DMC) and ethylene carbonate (EC) solvents wherein said solvents are present in a weight percent ratio range from about 95 DMC:5 EC to 20 DMC:80 EC.

Abstract: A spread-time code division multiple access (ST-CDMA) technique is disclosed for bandlimited access to a channel. With ST-CDMA, pseudo-random (PN) sequences are assigned to each transmitter in the multi-transmitter system, and the Fourier transform of the transmitter pulse for a given transmitter is determined by modulating the phase of the desired transmitter spectrum by the PN sequence assigned to the transmitter. The data symbols produced by the transmitter are conveyed by delayed versions of the transmitter pulse. The transmitted data for a particular transmitter is recovered at a receiver synchronized to the transmitter by sampling the output of a filter matched to the corresponding transmitter pulse.

Abstract: A 2.times.2 polarization beam splitter comprising two parallel waveguides and two crossing waveguides coupled in an X-configuration to the parallel waveguides by four adiabatic .gamma.-junctions which transfer only one of the two orthogonal polarization modes across the junctions, e.g., the TE mode. The crossing waveguides may be of different widths and cross at a very shallow angle so that little cross-talk occurs at the crossing.

Abstract: Apparatus, and accompanying methods for use therein, for illustratively implementing a large (e.g. approximately 1 Terabit/second) packet switch (200) or a non-buffer based statistical multiplexor (1810), using a crossbar matrix network in which, first, the output ports of individual switching elements (e.g. 1340.sub.1,1, 1340.sub.2,1) are partitioned into various groups (e.g. 1110) in order to share routing paths (links) (e.g. 1115.sub.1, 1115.sub.2, . . . , 1115.sub.K) among the elements in any such group and, second, the outputs of each such group are themselves recursively partitioned into a succession of serially connected groups (e.g. 1140, 1160) that each provides a decreasing number of outputs until one such output is provided for each corresponding output port (278.sub.1, 278.sub.2, . . . , 278.sub.N) of the switch.

Abstract: A rheological device suitable for measuring the rate of polymerization of ultraviolet sensitive polymers includes a part of open-ended cylindrical fixtures having removable quartz windows at one end. The upper fixture is adapted with a window which permits light to enter and impinge upon the surface of an elliptically-shaped mirror. Curing is monitored by measuring the elastic and viscous moduli during polymerization.

Abstract: A method and apparatus for controlling the growth of a multispecies film. During the film growth, an ellipsometer continuously monitors the surface on which the film is growing. The ellipsometer data is used to calculate the effective complex dielectric constant of the thin-film/substrate structure. A sequence of such data is used in a model calculation to determine the composition of the top portion of the thin film. The measured composition is compared with the target composition and the amount supplied of one of the species is correspondingly changed.

Abstract: A reactive gas detection system provides early warning of gas emissions that often occur in developing fire conditions in environments such as telephone system central offices where halogenated substances, for example polyvinyl chloride wire insulation and brominated fire retardant materials, are prevalent. Multiple microbalance detectors (122) comprising quartz crystal oscillators coated with a layer of zinc or zinc compound are distributed about a premises and the rate of change of crystal oscillation frequency is cyclically monitored by a frequency counter (130) under control of a data processor (112). The detectors are specifically reactive to the halogen acid gases emitted during pyrolysis of the noted substances and exhibit a significant differential frequency change in the presence one or more of these gases well in advance of the outbreak of flame, smoke, or other normally detectable combustion products.

Abstract: Rapid restoration of a telecommunication path between network nodes after an interrupting network link failure utilizes a distributed system of selective flooding for dynamically reconfiguring the internodal path in a manner which will ensure the most economical use of intermediate links. A help message transmitted from one of the terminating nodes to each contiguous neighboring node requests use of the uncommitted bandwidth of each respective link. This wave of messages is propagated selectively, along paths having maximum available bandwidth and least number of links, through the network by each successive receiving node until the help message reaches the other terminating node of the failed link. An acknowledgement message returned to the initial terminating node via propagation links offering the maximum bandwidth establishes a reconfigured path providing the greatest bandwidth recovery.

Abstract: An impedance-matched semiconductor detector formed on a portion of a waveguide. The waveguiding layer of the waveguide has one refractive index and the light absorbing layer of the detector has another refractive index. An impedance matching layer is formed between the waveguiding layer and the light absorbing layer and has a refractive index intermediate between those of the waveguiding layer and the light absorbing layer.

Abstract: A customer premises network for interfacing customer premises equipment with a broadband digital trunk and exchange network comprises a relatively large bandwidth optical broadcast bus for broadcasting downstream data to the customer premises equipment and a smaller bandwidth looped bus for transmitting upstream data from the customer premises equipment. The units of customer premises equipment are connected by the looped bus in a daisy chain.

Abstract: A Josephson junction (100) is employed as a very-high-speed frequency demodulator for detecting a frequency-shift-keyed (FSK) modulated signal (201) in a microwave or lightwave communication system. The voltage induced across the junction in response to an incident FSK modulated radiation signal follows the frequency variations in the incident wave thereby directly demodulating the information signal from its carrier. In the disclosed embodiment an FSK modulated optical signal is mixed with a local oscillator (303) signal, which is then incident on a photodetector (305). The resultant microwave-frequency signal is then applied over a two-wire transmission line (308) to the Josephson junction (307) for direct demodulation.

Abstract: A concentrator which concentrates and preserves the order of two lists of packets includes a computation network and a routing network. The computation network computes routing addresses based on concentration bits contained in the packets and the routing network routes the packets to the computed addresses.

Abstract: An optical switch for use in a fiber optic telecommunications network is disclosed. An important feature of the inventive switch is its multicast capability. The inventive switch utilizes two internal networks, an optical network for transmission and an electronic network for control. Illustratively, the transmission network is an optical star network which links the input ports and output ports of the invention switch. The electronic control network is in the form of a track of ring which surrounds the optical star and sequentially connects the input and output ports.

Abstract: An elongated multi-layered structure including multiple symmetrical two-sided fuel cells is made by a low-cost continuous process. Each cell assembly derived from the structure comprises two basis cells having a common positive electrode. By rolling each cell assembly into a spiral, a compact package having two cells connected in parallel and characterized by a relatively large current capabilty is realized. In the spiral package, conductive corrugations are utilized between adjacent surfaces of the rolled assembly to ensure that a fuel/oxidizer mixture can access permeable electrodes formed on the respective surfaces of the assembly.