Abstract: The specification describes a new MOS transistor structure in which the source gate and drain are formed within a trench in the semiconductor substrate. The gate width is determined by the depth of the trench and can be increased substantially without increasing the surface area occupied by the transistor. The result is a transistor with exceptionally high gain for a given surface area. Forming the transistor within and over a series of trenches further enhances this effect.

Abstract: An electronic circuit board electrically connected to other circuits of a data processing system by means of a bus, may be removed and re-inserted in the system without the necessity of disabling other circuits connected to the bus. A latch actuated switch provides a control signal in anticipation of circuit board removal. The control signal activates a finite state machine which seizes control of the bus after completion of any current bus communications and stops the generation of clock pulses normally required in bus communications. When contact is physically broken between the board and its corresponding connector, the finite state machine restores the bus clock pulses and relinquishes control of the bus. When a board is to be inserted in an open connector, contact between the board and the connector is sensed by the finite state machine which causes the bus to be seized and the bus clock pulses to be temporarily inhibited.

Abstract: There are disclosed a method and apparatus for producing laser pulses at two wavelengths alternately by switching the oscillations of a distributed feedback semiconductor laser of the continuous grating type back and forth across the stop band. The necessary shaping of the gain or index of refraction characteristic along the path of the oscillations is accomplished in part by two top electrodes, one of which is longer than the other along that path, and by varying the current supplied to at least one of those electrodes in the appropriate sense. Applications for optical communication and for optical logic are disclosed, the preferred embodiment being a transmitter for an optical communication system with minimal chirp of the optical pulses, in which pulses at one of the wavelengths are modulated at a bit rate exceeding 1 Gigabit by direct-modulation control of the switching of the laser, and the pulses at the other of the two wavelengths are discarded.

Abstract: Distributed region optical sensors for chemical detection are provided by utilizing optical fiber technology. A core is provided with a surrounding region that is permeable to the chemical to be detected. A composition whose optical characteristics are altered upon interaction with the chemical to be detected is provided within the permeable material. This change in optical characteristics allows chemical detection through detection of light guided by the fiber.

Abstract: A squaring circuit (FIG. 1, 100; FIG. 3, 300) includes an operational amplifier (10) having its positive input terminal connected to ground, its negative input terminal connected through a nonlinear voltage-to-current conversion device (FIG. 1, T.sub.2, T.sub.3 ; FIG. 3, M.sub.1, M.sub.2, T.sub.2) to a balanced source of the input voltage (.+-.V.sub.IN), and its output terminal connected through a linear current-to-voltage conversion device (FIG. 1, R.sub.1 ; FIG. 3, T.sub.1, C.sub.1) to its negative input terminal. The circuit can be made to have a balanced output (FIGS. 2 and 5), and the circuit can be made in the configuration of either a continuous-time circuit (FIGS. 1 and 2) or a sampled-data circuit (FIGS. 3 and 5).

Abstract: Disclosed is an ac plasma display of the type employing three electrodes per pel which is useful for full color displays. A phosphor layer is provided over the cover electrodes and the usual electron emission layer is eliminated or thinned down. An additional pulse is provided to the cover electrodes to aid in charge transfer during the write stage in order to compensate for the absence of significant electron emission.

Abstract: An integrated circuit comprises a resistor that is formed by doping a semiconductor region that is defined by a layer, typically polysilicon, that also defines the gate electrode of field effect transistors in the integrated circuit. The well-controlled linewidth of features defined in this layer provides for tight resistor tolerance, and also allows the value of the resistor to track changes in other features defined by this layer.

Abstract: An optical switch (100) is disclosed for switching spatially-separated complementary optical signals from a row of a two-dimensional input storage array (132) to a selected row of a two-dimensional ouptut storage array (133). The switch includes an input system (101) for converting temporally-separated information represented by a serial bit stream of complementary optical signals into a spatially-separated format for storage in the input array. An output system 105 is also included for converting the switched, spatially-separated information in the output array into a temporally-separated format for serial transmission on plurality of optical output fiber pairs 160(1)-160(N). The input and output systems enable the switch to perform both time- and space-division switching with only a single stage of switching.

Abstract: A method of selective area epitaxial growth using a scanning ion beam is described.

Abstract: It has been discovered that fused silica doped with approximately equimolar amounts of Al and P, has advantageous properties that make such co-doped glass useful in a variety of applications, including optical fiber, especially polarization-maintaining optical fiber, and planar waveguides in optical and optoelectronic devices. In particular, such co-doped fused silica can have a refractive index that is lower than, or at least not significantly greater than, that of pure fused silica, even though both Al and P individually are known up-dopants for silica. The co-doped fused silica also can have a relatively low working temperature, while otherwise maintaining many of the desirable properties of fused silica, e.g., chemical inertness and relatively low coefficient of thermal expansion.

Abstract: A discrete transform cosine circuit utilizing symmetries of the cosine matrix of coefficients to allow all multiplications to be done by "constant multipliers" comprising combinations of look-up tables and adders. Transform coefficients are developed by dividing each into a sequence of blocks of preselected size, the information in the blocks is sorted to develop a specific order and the reordered blocks are applied seriatim to a first one-dimensional cosine transform circuit employing the constant multipliers. The output of the first cosine transform circuit is applied to a transposing memory and then to a second cosine transform circuit that also employs "constant multipliers".

Abstract: There is disclosed an optical ranging system adapted for use with widely varying return signal levels. Automatic signal level control is achieved in two parts, a passive optical part and an active electronic AGC part. The optical part is based on the coaxial arrangement of transmitting and receiving elements in which the shielded transmitting element is mounted in front of the receiving element, which includes Fresnel lens which comprises a plastic casting. The electronic AGC portion of the system includes means for providing a voltage drive (with low internal impedance) for the final AGC transistor when it would tend to be slow, so little phase shift in the control results from changes in the signal levels. Thereby, the determination of distance (the ranging) by phase shift measurement is kept reliable as signal level changes.

Abstract: An on-board self diagnostic capability is realized in a circuit board with a microprocessor which is located on the circuit board and which interacts for diagnostic purposes with the functional circuitry on the board. The microprocessor interacts with an electrically erasable read-only-memory (EEROM) that is also located on the circuit board. Diagnostic signals occurring during the circuit board's normal operation are automatically detected and stored in the EEROM. Additionally, a control port at the circuit board permits activation in the microprocessor of diagnostic routines that accept input test data, apply test sequences to the functional circuitry and store the diagnostic results in the EEROM. Also, through control of the microprocessor, the EEROM is accessed to retrieve previously stored diagnostic results.

Abstract: Junction field effect transistors are described with unusually short gates and a self-aligned structure which permits close approach of the source and drain electrodes to the p-n junction. Such devices have high speed, high gain and are usefully combined with other field effect transistors in integrated circuits.

Abstract: A transistor device using an interdigitated gate and electrode surface structure to control thermionic emission over a potential barrier is described. Complementary logic structures comprising such transistors are discussed.

Abstract: An improved compound semiconductor hot electron transistor (HET) having room temperature current gain .beta.>10 is disclosed. Disclosed are also means by which improved HET performance can be obtained. Among these means is choice of the base layer material such that the hot electrons injected into the base have k.sub.i,2 /k.sub.i,1 >0.2, where k.sub.i,1 and k.sub.i,2 are the components of the electron wave vector respectively normal and parallel to the emitter/base interface. A further means is choice of collector material such that the hot electron velocity component normal to the base/collector interface remains relatively unchanged upon passage of the hot electron through the base/collector interface. For instance, an appropriate superlattice in the collector region may be used to achieve such matching. Causing quantization of the ambient charge carrier states in the base can reduce hot electron scattering in the base.

Abstract: To facilitate testing in the manufacture, operation, and maintenance of substrate-supported assemblies such as, e.g., optical transmitters and receivers in subscriber-loop and local-area networks, an assembly is provided with built-in optical test features at selected test points. Preferred test features may include side-by-side couplers or reflector taps as may serve to extract or insert light into a substrate-supported waveguide. Testing may further involve the use of a test set having optical components in alignment with test features of an assembly.

Abstract: A method and apparatus for controlling calls in in a distributed processing communications switching system. A call is assigned to any one of a plurality of call control processors. The assigned processor thereafter directs the establishment of communications connections for that call. In the exemplary embodiment, the control of a cellular mobile communications switching system, a high speed data ring is used to communicate among a switching network, the call control processors, and call assignment processors of the system. Advantageously, each of the call control processors can be fully utilized since each may be flexibly assigned to any set of communications ports or terminals. New calls to a terminal which is already on an existing call are assigned to the call control processor assigned to control the existing call. Advantageously, call data for all calls to that terminal are therefore under the control of a single processor.

Abstract: An arrangement for processing a speech message which uses arbitrary value codes to form time frame excitation signals. The arbitrary value codes, e.g., random numbers, are stored as well as signals indexing the codes and transform domain signals corresponding to the arbitrary codes are generated. The speech message is partitioned into time frame interval speech patterns and a first signal representative of the transform domain speech pattern of each successive time frame interval is formed responsive to the partitioned speech message. A plurality of second signals representative of time frame interval patterns corresponding to the transform code signals are generated responsive to said set of transform signals. One of the arbitrary code signals is selected jointly responsive to the first and second signals of each successive time interval to represent the time frame speech signal excitation, and the index signal corresponding to said selected arbitrary code signal is output.

Abstract: The disclosed means for coupling an optical fiber and an opto-electronic device (e.g., LED, Laser, or photodetector) comprises a first body having two substantially parallel major surfaces, with a recessed portion (a "well") formed in one surface, and a through-aperture extending from the other surface to the well. Conductive means extend from the former surface onto the bottom of the well, and the opto-electronic device is to be mounted in the well such that the device does not protrude above the plane of the associated surface, such that electrical contact is established between the device and the conductive means, and such that the active region of the device is centered upon the through-aperture. The first body is advantageously from a (100) Si wafer by means of standard Si processing techniques, including selective etching. The assembly can be mounted on a substrate, e.g.