Abstract: A switching network where a large class of combinatorial designs which are well known in the mathematical literature are for the first time applied to advantageously define the pattern of permanent connections effected between network input channels and initial network crosspoints, illustratively by a connection arrangement of a two-stage, rearrangeable network. The class of combinatorial designs comprises designs of three types: (1) block designs, (2) orthogonal arrays, and (3) difference sets. Each of these is used in a unique manner to derive an advantageous pattern of permanent connections.

Abstract: An adaptive time-discrete filter having an impulse response h(i) with i=0,1,2, . . . for forming a cancelling signal from synchronous data symbols (for example to cancel echoes or lagging intersymbol interference) comprises a transversal filter section (12) having adjustable coefficients C.sub.i with i=0,1,2, . . . , N-1 for realizing the first N values h(i) of the impulse response as well as a recursive filter section (12') for realizing the values h(i) with i=N,N+1, . . . . The recursive filter section (12') receives the input signal delayed over N-1 discrete time intervals from the adaptive filter as an input signal x(n) and forms an output signal y(n) according to the relationship:y(n)=C.sub.B [C.sub.A .times.(n-1)+y(n-1)]where C.sub.A is equal to the last adjustable coefficient C.sub.N-1 of the transversal filter section (12) and C.sub.B is a predetermined fixed coefficient.

Abstract: A method for etching metal layers including aluminum to create tapered sidewalls is disclosed. The method features the use of trifluoromethane and chlorine in controlled amounts to create a tapered metal layer profile.

Abstract: A mechanical connection arrangement for two polarization-maintaining optical fibers (20--20) includes two ferrules (40--40). Each of the optical fibers to be connected includes an outer cladding layer (23) having a hybrid cross section transverse to a longitudinal axis of the fiber. The hybrid cross section is defined by two parallel sides and by two generally arcuate end portions. One of the polarization axes of the fiber is parallel to the parallel sides of the fiber. The ferrules were adjacent portions in a length (110) of stock material and are positioned in support means such that end faces of the ferrules which were contiguous to each other prior to the ferrules being separated from the length of material are adjacent to each other in the connection arrangement. Each ferrule prior to separation has a tab (126) associated therewith such that the tab of the adjacent portions are aligned longitudinally.

Abstract: Buffer memory overflow control is realized by controlling the amount of packet data being inputted to the buffer memory in response to the amount of packet data stored in the buffer memory. Depending on the type of coding being employed and the amount of data stored in the buffer memory, one or more groups of bits are controllably dropped from the packet information field being inputted into the buffer memory.

Abstract: A voltage controlled oscillator (VCO) comprises the series arrangement of two signal inverters whose outputs are coupled to the input of the first signal inverter through a feedback loop, and a control circuit including a series arrangement of two diodes arranged in the same direction, whose interconnected electrodes are coupled to the input of the first inverter. The other electrodes of the diodes form inputs for two control voltages with which the frequency of the VCO can be varied over a continuous range. The VCO is used in a phase locked loop which includes a phase detector for generating an error signal representative of a phase difference between a reference signal and a signal taken from the VCO, and a loop filter for producing a control signal from the error signal. The phase detector is arranged as an EXOR gate with a first input for the reference signal voltage and a second input for the output voltage of the VCO.

Abstract: A method for substantially improving the throughput of circuit simulators is disclosed for arriving at the steady-state of closed-loop self-regulated piecewise-linear or periodically driven piecewise-linear systems. The disclosed method is based on the Newton-Raphson procedure, which enables it to outperform brute-force methods by an order of magnitude in speed, and a special algorithm for the determination of the system sensitivity, which directs it to converge to the solution of systems with high sensitivity with respect to the subinterval timing, where most of the existing methods fail. The method is an iterative procedure with each iteration starting out with the determination of the sensitivity of the final state vector in a switching cycle with respect to the initial state vector of the same switching cycle. This is followed by a Newton-Raphson iteration to predict the initial state vector of a steady-state operation.

Abstract: Briefly, in this invention, the output optical power of an optical amplifier is determined by detecting and measuring the electrical signal induced on the bias lead of the optical amplifier when an optical data stream with additional amplitude modulation passes through the optical amplifier. This additional amplitude modulation can consist of a base band signal, a pilot tone and/or a sub-carrier which is amplitude modulated, frequency modulated or phase modulated. The modulation depth and bandwidth of the additional amplitude modulation should be kept small enough that the data stream is not excessively affected. The induced electrical signal provides a measurement of the optical power at the output facet of the optical amplifier. Control of the output power of the optical amplifier is effected by controlling the bias current applied to the bias lead of the optical amplifier.

Abstract: A transceiver arrangement for full-duplex data transmission over a two-wire circuit (6) comprises a transmitter part (1-4), a receiver part (7, 8, 11-15), a hybrid junction (5) to interconnect the transmitter and receiver parts and the two-wire circuit (6), and an echo canceller 9 whose input is connected to the transmitter part and whose output is connected to the receiver part, the arrangement further comprising switching means (S.sub.1) enabled in a test mode for disconnecting the receiver part (7, 8, 11-15) from the two-wire circuit (6). With a single test the proper functioning of the transmitter and receiver parts of the arrangement as well as that of the echo canceller (9) can be checked, because the arrangement also comprises switching means (S.sub.

Abstract: A digital signal processor implementation of dynamic time warping for automatic speech recognition using a single memory array that stores only one sequence of accumulated correspondence values and detecting whether or not the constraint on horizontal path compression has been exceeded by storing negatives of calculated accumulated correspondence values to indicate horizontal path movement. The accumulated correspondence values are stored in the array in descending order; and memory locations of that array are reused as accumulated correspondence values are calculated representing the correspondence between a plurality of reference time frames and a plurality of unknown time frames representing an unknown word or utterance. When path movement is from an adjacent horizontal correspondence node to the present node, the negative of the calculated accumulated correspondence is written back into a memory location associated with the present node.

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 liquid crystal device includes a liquid crystal material (30) in which the molecules (15) form a helix having its axis essentially parallel to the plates (13, 20) of the device. A suitable electric field (E), applied essentially perpendicular to the plates, causes planes of the directors (n) to rotate about the field direction to an acute angle .phi. with respect to the helix axis, thereby inducing alternating bands of splay and bend in the material. Such configurations, which have polar symmetry, give rise to the flexoelectric effect in which the polarization (P) of the molecules tends to be parallel to the applied field, and the magnitude of the field is linearly related to tan .phi.. The ability to rotate the directors means that the optical properties of the material can be changed.

Abstract: A selectively tunable coherent optical receiver includes a tunable laser for producing a selectable local oscillator frequency for receiving any one of a group of received optical channel signals. The tunable laser is controlled by a feedback loop and a digital processor that stores values of laser bias current. The arrangement produces an exact local oscillator frequency for operating with any one of the group of selectable received channel signals which are spaced over a range of optical carrier frequencies. This receiver avoids frequency sticking and very long pull-in time and determines when there is a missing channel or missing channels.

Abstract: A hollow cathode type inverted cylindrical magnetron apparatus construction comprises two separate units each having a rectangular C shape cross section. The two C shaped units are positioned together to form a hollow rectangular parallelpiped like cavity and articles to be sputtered are passed through this cavity.Bolted construction of simple elements having simple geometry are used to produce a very inexpensive structure which is easily serviceable. This magnetron construction uses permanent magnets all having the same north south pole orientation located behind the target material and surrounded on three sides by magnetic permeable material to confine the magnetic flux path. Hence the lines of force tend to be parallel to the substrate surface of the article very near to that surface and heating of the substrate is minimized. Cooling is provided by coolant carrying tubes interspersed between the magnets and the target material.

Abstract: In a dynamometer, a multi-roller sheave is positioned between a cable, or other elongate element, supply and the cable destination so that the cable rolls over the multi-roller sheave. The center axis of the cable changes direction from one side of the multi-roller sheave to the other side. Tension in the cable causes the multi-roller sheave to move and consequently stress a strain gauge. A signal produced by the strain gauge is amplified into a signal that accurately indicates the tension in the cable. Friction and wear between the cable and the dynamometer are eliminated for all practical purposes. Very accurate readings of tension are obtained.

Abstract: An alignment sleeve (66) for holding two conically shaped portions (30--30) of plugs (24--24) each of which terminates an optical fiber (25) includes two conically shaped cavities (68, 70) communicating through a common minimal diameter plane (72). After the sleeve has been molded, a tool (100) faced with an abrasive material is inserted into each cavity of the sleeve and turned rotatably while a force is applied in a direction parallel to the longitudinal axis of the tool. This causes material to be removed from the walls defining the cavities so that when the two plugs are inserted into the cavities, the axes of the fibers will be aligned coaxially and the end faces of the fibers will have a predetermined separation. The apparatus of this invention also may be used to adjust a length measurement of plugs. This is accomplished by inserting a plug into a conically shaped cavity of a tool.

Abstract: A switching system is described in which routing information, which may be associated with packets originating in cellular calls, is divided into information which does not change as the subscriber crosses a cell boundary, and information which does change as the subscriber crosses a cell boundary. Routing procedures associated with the information which does not change as the subscriber crosses a cell boundary are established and stored in the memory of the switch at the beginning of the call. However, routing procedures associated with the information which does change as the subscriber crosses a cell boundary may be derived from the header information of each packet as it arrives at the appropriate portion of the switch.

Abstract: The connector comprises two conector portions (1, 3), each of which comprises an inner contact member (5, 49) which is coaxially surrounded by an outer contact member (23, 59) whereto it is mechanically connected via an insulating body (9, 53). At its free end each contact member (5, 23, 49, 59) comprises a contact face (5', 23', 49', 59') which extends perpendicularly to its axis, at least one (5', 59') of each pair of cooperating contact faces (5', 23'; 49', 59') being so large that, after the coupling of the two connector portions (1, 3), a suitable electrical connection is realized between the cooperating contact members (5, 23; 49, 59) it the axes of the two connector portions have been displaced with respect to one another no more than a predetermined distance (d).

Abstract: A multiplexer is arranged for interleaving blocks of bits from tributary lines. Sequences of blocks of digital bit streams are received in frames from each tributary line. Each frame includes tributary line identification information and plural blocks of bits. Each block of digital bits includes plural data bits and a parity bit. The sequence of blocks from one tributary line also includes in a periodic one of the parity bit positions, a bit containing control information. The blocks of digital bit streams are multiplexed into a single multiplexed bit stream.

Abstract: A new method for fabricating a semiconductor device, e.g., a MOS or MES IC, as well as the resulting device, are disclosed. In accordance with the new method, a semiconductor device is formed, at least in part, by forming a material region which includes metal, e.g., elemental metal or a metal-containing compound, on a semiconductor substrate. One or more dopants are implanted into the material region, and the substrate is heated in order to diffuse the dopants out of the material region and into the substrate, thus forming a dopant-diffused substrate region, e.g., a source or drain. Significantly, the new method involves implant conditions which yield a material region-to-substrate specific contact resistance equal to or less than about 10.sup.-6 .OMEGA.-cm.sup.2. In addition, the new method involves heating temperatures and heating times which yield a dopant-diffused substrate region having a depth, relative to the top of the material region, equal to or less than about 0.2 micrometers.

Abstract: Apparatus and method for efficient multiplication of a matrix by a vector. The multiplication is realized by rearranging the matrix so that a plurality of adjacent columns form a set, and each set is characterized by a certain pattern in each column. One set contains columns of only a single .+-.1 entry, another set contains columns with two .+-.1 entries, and still another set contains columns with entries that are other than .+-.1. Each of the sets is treated differently during the calculations in accordance with a maximal * cover approach, and a result is developed by multiplying each row in the rearranged matrix by a corresponding element of the vector to form partial results, and accumulating the partial results.

Abstract: A customer inquiry unit that allows the recognition of human speech in the presence of an initial prerecorded message transmitted by the customer inquiry unit via a telephone network. The customer inquiry system is designed to be utilized to respond to inquiries received via the telephone network. The system functions by responding to a telephone call received via the network to transmit an initial speech message to the customer. Due to a variety of network problems, a portion of the speech energy of the message is reflected back to the inquiry system. This reflected energy is commonly referred to as an echo. If the customer starts to speak before the inquiry system has finished the initial message, the system utilizes an echo canceler to remove the echo received back from the telephone network and only transfers the speech response to a recognition subsystem. The echo canceler adapts to the telephone network during the initial portion of the initial speech message before the customer can respond.

Abstract: In order to reduce parasitic capacitive cross-coupling in an integrated circuit, metallization lines in an array--for example, an array of word lines, of bit lines, or of bus interconnects--are geometrically arranged in a systematically progressive laterally (sidewise) marching sequence, whereby the identity of the lines located on either side of a given line keeps changing.

Abstract: Drawn optical fiber is provided with at least one layer of a coating material. The coating material typically is a UV curable material and provides the optical fiber with mechanical and environmental protection. It has been found that the temperature at which the optical fiber is cured has a pronounced effect on the modulus of the cured coating material. In order to provide a coated optical fiber of which the coating material has a desired modulus, the temperature of the coating material during cure is controlled by controlling the amount of energy of infrared wavelength which impinges on the coating material.

Abstract: Method and apparatus for optimizing the operational state of a system employing iterative steps that approximately follow a projective scaling trajectory or an affine scaling trajectory, or curve, in computing from its present state, x.sub.0 to a next state x.sub.1 toward the optimum state. The movement is made in a transformed space where the present (transformed) state of the system is at the center of the space, and the curve approximation is in the form of a power series in the step size. The process thus develops a sequence of tentative states x.sub.1, x.sub.2, x.sub.n . . . . It halts when a selected suitable stopping criterion is satisfied, and assigns the most recent tentative state as the optimized operating state of the system.

Abstract: A relatively inexpensive and relatively efficient coupler is obtained by connecting two fiber collections with a polymer material, provided the numerical aperture of the two collections are relatively well-matched to each other and to the polymer region. This efficiency is achieved despite relatively large mismatches in the refractive index of the resin material relative to the fibers. Couplers for optical backplanes are produced in one embodiment utilizing plastic materials. In this technique, a collection of fibers is inserted on each end of an enclosure such as a tube that is filled with a polymer that is subsequently cured.

Abstract: An integrated voice and data network includes a multiplexer arranged with a voice queue for storing voice packets and a data queue for storing data packets. Voice packets are transmitted for a predetermined interval T1. Data packets are transmitted for a predetermined interval T2. The predetermined intervals T1 and T2 may be of different durations. A separate signaling queue can be provided for storing received signaling messages. If a signaling message is moved into the separate signaling queue during either interval T1 and T2, that interval is suspended and the transmission of voice or data packets is interrupted until the entire signaling message is transmitted. Then the interrupted voice or data transmission is resumed for the remainder of the suspended interval T1 or T2. As an alternative, signaling messages can be transmitted during predetermined intervals between the intervals T1 and T2. Block dropping of low order voice bits also is described for reducing congestion at the node.

Abstract: The present invention relates to a multichannel multihop lightwave communication network which allows packet concurrency in the network while avoiding the need for agile optical devices. The network comprises a lightwave communication medium (10) for supporting a plurality of independent user nodes; and a plurality of N network interface units (NIUs) (11). Each NIU is connected to the lightwave medium and one or more separate user nodes and comprises a trnasmitter section (28-35) and a receiver section (20-27) which are each fixedly assigned to transmit and receive, respectively, over a single channel or a plurality of separate channels to or from other NIUs of the network. In a connectivity pattern for one embodiment of the network, the NIUs are divided into k groups of p.sup.k NIUs such that each NIU of a first group of p.sup.

Abstract: A switching network where a large class of combinatorial designs which are well known in the mathematical literature are for the first time applied to advantageously define the pattern of permanent connections effected between network input channels and initial network crosspoints, illustratively by a connection arrangement of a two-stage, rearrangeable network. The class of combinatorial designs comprises designs of three types: (1) block designs, (2) orthogonal arrays, and (3) difference sets. Each of these is used in a unique manner to derive an advantageous pattern of permanent connections.

Abstract: In an angle diversity receiving system, the primary and diversity signals are produced by a waveguide signal separator coupled to a single receiving antenna.The separator operates by converting selective higher order modes in the antenna into fundamental modes that will propagate in its two output waveguides. The result is a robust system that operates over a frequency band wide enough to cover both the 4 GHz and 6 GHz common carrier bands with both horizontally and vertically polarized signals, and that can use a wide variety of antennas.

Abstract: A digitally tuned optical frequency synthesizer includes a laser control arrangement for tuning the laser over a range of frequencies. The laser is tunable in response to different magnitudes of injected bias current. A digital processor determines bias current values which produce the desired different operating frequencies corresponding to a set of Fabry-Perot resonant frequencies. Those current values are stored in the digital processor for ready retrieval. During operation, one of the bias current values is retrieved and is applied to the laser. If the laser characteristic curve has drifted, an incremental bias current is determined and is added to the retrieved bias current value. For future use, this new bias current value is stored in the digital processor in place of the originally retrieved bias current value. The digital processor additionally calculates new bias current values for all of the desired frequencies of operation and stores those new values for subsequent selection.

Abstract: An optically bistable device, such as a symmetric self electro-optic effect device (S-SEED), is forced into a metastable state prior to the incidence of an optical input signal thereto, thereby increasing the sensitivity of the optically bistable device to the optical input signal, reducing both the switching time and the optical input signal energy required to switch the device. The metastable state is entered into by one of three techniques: (1) turning off the bias voltage V.sub.0 of the device with optical bias beams on then turning on the bias voltage V.sub.0 with the optical bias beams off; (2) applying a predetermined voltage to a node in the device, the predetermined voltage being substantially the metastable state voltage or V.sub.0 /2; or (3) subjecting the device to equal intensity optical bias beams having a wavelength longer than the exciton wavelength.

Abstract: The present invention relates to a self-synchronous spread spectrum transmitter and an associated remote spread spectrum receiver which communicate with each other by the transmission of both (1) a spread spectrum Pseudo Noise Code (PNC) sequence signal, and (2) a combined PNC sequence plus the data information (PNC+data) signal. The two signals can be transmitted concurrently using either different frequency bands or on a quadrature carrier; or the two signals can be transmitted with a time offset between signals. At the receiver the PNC and the PN+data signals are separately recovered for the case of the concurrent transmission techniques, and directly mixed to despread the received signal and recover the data signal at baseband.

Abstract: A control amplifier enabling large bandwidths (.apprxeq.2 GHz) and a large dynamic control range (.apprxeq.25 dB). The amplifying element is a MESFET. This MESFET is automatically biased. Thus, FET's whose pinch-off voltage is subject to a large variation can be used without further adjustments.

Abstract: Advanced packaging techniques are utilized to provide updated packaging for optical transmitters and receivers. In particular, the hybrid integrated circuit (HIC) used to form either the transmitter or receiver circuitry in the prior art has been replaced by a plastic dual-in-line package (DIP). The DIP includes specialized leads (prongs) formed through the short end of the DIP to provide direct connection to the optical device. These end-prong leads thus significantly decrease the parasitic capacitance associated with conventional DIP connections. A capacitor may be molded into the DIP across the power supply leads to provide filtering for the package. Thermal dissipation is provided by two separate means in this package.

Abstract: A process for electroplating palladium containing deposits from baths comprising a combination of a surfactant and a brightener combination. The surfactant is an alkyl, ammonium-type salt containing 4 to 35 carbon atoms. The brightener is 0-benzaldehydesulfonic acid, 1-naphthalene sulfonic acid, 2-naphthalenesulfonic acid, benzenesulfinic acid, oxy-4,4-bis (benzene) sulfinic acid, p-toluene sulfinic acid, 3-trifluoromethyl benzene sulfinic acid, allyl phenyl sulfone, 0-benzoic sulfamide, benzylsulfonyl propionamide, phenylsulfonyl acetamide, 3-(phenylsulfonyl) propionamide, benzene sulfonamide, bis (phenylsulfonyl) methane, guanidine carbonate, sulfaguanidine or nicotinic acid. This combination provides deposits having superior adhesion and ductility.

Abstract: A process is described for electroplating palladium and palladium alloys. The process involves the use of an alkyl hydroxyamine as complexing agent and is particularly good for palladium alloys such as palladium-nickel and palladium-cobalt.

Abstract: In an optical fiber communication system that operates at a wavelength .lambda..sub.o and comprises optical fiber having a cut-off wavelength .lambda..sub.c >.lambda..sub.o, a "grating", with parameters chosen such that the grating causes resonant coupling between a predetermined guided mode (e.g., LP.sub.11) and a tunneling-leaky mode, can be advantageously used to remove unwanted guided modes. Such removal can substantially improve the bandwidth of such a system.

Abstract: In an optical switching network, a master optical space switch is interconnected with remote slave equipment for switching block-multiplexed messages among the remote equipment. The master optical space switch responds to a frequency reference clock and steps through a sequence of states, or configurations, for establishing various routes among the remote equipment for appropriately routing the messages to correct destinations. The frequency reference clock also is distributed to the remote equipment. During one of the states per frame, each remote slave equipment transmits a distinct signature signal. All of the slave equipments are connected through the master optical space switch to return to themselves their own signals transmitted during that time slot. Each remote slave equipment compares the returned signal with the originally transmitted signature signal to determine how much the round trip delay has varied from a nominal value.

Abstract: Apparatus for preventing the unauthorized detection of the start and end of packets being communicated within a packet switching system. The packet switching system comprises a plurality of packet switching networks that are interconnected by trunks. Each switching network has a number of trunk controllers with each terminating one of the trunks interconnecting that network to other networks. Each controller has an encrypting circuit for only encrypting the flag of each packet before the packet is transmitted on the connected trunk and a decrypting circuit for decrypting the flag of each packet received from the connected trunk. The decrypting circuit on the receiving side of a trunk recovers flag synchronization with the encrypting circuit on the transmitting side of the trunk by the exchange of special packets. Each flag comprises a plurality of bytes.

Abstract: Apparatus for encoding speech using a code excited linear predictive (CELP) encoder using a virtual searching technique during speech transitions such as from unvoiced to voiced regions of speech. The encoder compares candidate excitation vectors stored in a codebook with a target excitation vector representing a frame of speech to determine the candidate vector that best matches the target vector by repeating a first portion of each candidate vector into a second portion of each candidate vector. For increased performance, a stochastically excited linear predictive (SELP) encoder is used in series with the adaptive CELP encoder. The SELP encoder is responsive to the difference between the target vector and the best matched candidate vector to search its own overlapping codebook in a recursive manner to determine a candidate vector that provides the best match. Both of the best matched candidate vectors are used in speech synthesis.

Abstract: A binary tree multiprocessing array of plural signal processing elements, and having input/output for the array entirely through a root one of the processing elements, includes in each processing element thereof a hardware, pipelined, floating point, multiply/accumulate processing function for cooperating with a procesing element memory and a processing element input/output processing function to perform signal pattern matching of input digital signal sequences provided to and/or through the root processing element with respect to at least one digital signal sequence pattern stored in the memory.

Abstract: To overcome the deleterious effects of the nonuniform frequency modulation response in semiconductor lasers due to current injection in direct frequency modulation applications, it has been determined that the linewidth enhancement factor .alpha. be made as large as possible. In one embodiment, distributed feedback lasers well suited for frequency modulation lightwave communication systems are designed to have an integrated feedback element such as a corrugation grating whose effective pitch is selected to cause the Bragg wavelength and, therefore, the laser operating wavelength to be longer than the wavelength at substantially the maximum gain or gain peak in the semiconductor structure without the grating. That is, the wavelength of the grating is effectively detuned toward the longer wavelength and lower energy side of the peak of the gain profile.

Abstract: An efficient N.times.N star optical coupler suitable for mass production in integrated form is disclosed. The coupler can be realized using silicon technology to form a dielectric coupler slab and two arrays of strip waveguides all on a single glass substrate. Power transfer betwen the two arrays is accomplished through radiation in the dielectric slab with theoretical efficiency exceeding 30% under optimized conditions.

Abstract: A plurality of digital signals of one or more digital transmission bit rates are arranged to be combined by employing a unique common channel frame format. The channel frame format includes a plurality of data bit positions and a plurality of overhead bit positions. The number of data bit positions used is dependent on the particular incoming signal. Similarly, the number of frames generated during a specific common framing interval is dependent on the digital transmission bit rate of the particular signal. Specifically, the number of channel frames generated during the common channel frame interval is dependent on a number of equivalent so-called lowest transmission bit rate signals included in the particular signal being formatted. The overhead bits are distributed in the channel frame format.

Abstract: When making CMOS logic circuits, for example an inverter, it is frequently necessary to connect the sources of the p and n channel transistors to their respective tubs (n and p, respectively). The prior art required either a large contact window covering both source and tub regions, or else two standard size contact windows. The present technique forms the tub tie connection by the use of the same silicide layer that is formed on the source/drain regions, which typically also forms a gate silicide in the self-aligned silicide (i.e., "salicide") process. A conventional window may then be used to connect the silicide tub tie (and hence the source/tub regions) to a power supply conductor. A space saving is obtained, and increased freedom for placing the power supply contact window is obtained.

Abstract: Lower switching energies, enhanced electroabsorption and reduced tolerances on the operating wavelength of incident light are achieved while contrast between low and high absorption states is maintained in accordance with the principles of the invention by a self electrooptic device including an intrinsic quantum well region having an asymmetric electronic characteristic across a narrow bandgap subregion between the two wide bandgap layers defining the quantum well region. As a result, the quantum well region polarizes electrons and holes within the subregion in an opposite direction relative to a direction for an electric field applied to the device. The asymmetric electronic characteristic is realized as a compositionally graded, narrow bandgap layer or as a pair of coupled narrow bandgap layers of differing thicknesses separated by a thin wide bandgap layer.