Abstract: A vertical-cavity surface-emitting semiconductive laser has non-epitaxial multilayered dielectric reflectors located on both its top and its bottom surfaces, in order to facilitate fabrication of the reflectors and achieve high optical cavity gain and low electrical power dissipation.

Abstract: A high definition television system that is characterized by low transmission bandwidth is achieved by removing redundancies in the signal, encoding the remaining signals, and transmitting the encoded signal in a manner that is most compatible with the applicable standards. In the encoding, groups of signals to be sent are mapped to codebook vectors and the identities of the codebook vectors are sent together with those signals of the groups of signals that correspond to the codebook vectors. To insure that the total number of signals that are sent does not exceed the available capacity, the signals are sorted by a selected importance parameter and assigned for transmission in descending order of importance until the capacity is exhausted. Signals that are not assigned for transmission are discarded.

Abstract: In CMOS based integrated circuits, stricter design rules require source and drain junctions shallower than 2500 .ANG.. By using a specific device configuration, a shallow junction is obtainable while resistance to latch-up is improved and other electrical properties, e.g., low leakage current, are maintained. To achieve this result the p-channel device should have an activation energy of the junction reverse leakage current region less than 1.12 eV, with a junction dopant region shallower than 1200 .ANG. and a monotonically decreasing junction dopant profile.

Abstract: A digital logic circuit (100) is provided for multiplying, such as doubling, the frequency of an input clock pulse sequence of period T. The circuit in one embodiment includes complementarily clocked first and second chains of cascaded delay elements (12, 13 in A1, A2, A3, . . . and B1, B2, B3, . . . ). Further, the n'th one of set of clocked latches (14, 15, 16 in A2, A4, A6, . . . ) derives its input from the 2n'th one of the delay elements in the first chain, where n is a running integer index (n=1,2,3, . . . ). The circuit (100) also includes a set of two-input logic gates (11), one of whose inputs (IN) is the output (OU) of a separate one of the logic elements (12, 13) in the second chain and the other of whose inputs is an output (MO) of a separate one of the latches (14, 15, 16). Each of the outputs of these logic gates (11) is fed to a multiple input output logic gate (25) whose output has a desired double-frequency feature (edges at T/4) relative to the frequency of the clocked pulse sequence (CLK).

Abstract: Foreign exchange subscriber service is provided via a local ISDN exchange which selectively establishes switched connections between a customer's ISDN terminal and a trunk circuit dedicated to the foreign exchange line. The same ISDN subscriber line may be used for local service and foreign exchange service to several different foreign exchanges. The customer's ISDN terminal has a separate call appearance for each foreign exchange line and call appearance information is used in ISDN messages transmitted between the local exchange and the customer's terminal to uniquely identify local and foreign exchange service connections.

Abstract: Apparatus and method for controlling concurrent process access of infrastructures. The apparatus and method selectively locks nodes and tree structures to reserve lock a node and tree structure for subsequent exclusive and share locking by a process. Currently running processes have share read only access to the reserved locked node and tree structure until a subsequent exclusive lock is applied by the process to the reserve locked node and tree structure.

Abstract: An oscillator, such as a crystal oscillator, is presented for low jitter (low phase noise) applications, such as in frequency synthesizers or digital repeaters. The two terminals of a resonator are coupled to the input and output of an amplifier, the amplifier together with other components effecting a negative impedance. The inputs of a comparator are connected to the terminals of the resonator. The output of the comparator, preferably differential, is a signal having a frequency substantially determined by the resonator.

Abstract: A low loss, tunable optical filter (20) comprises two ferrules (24--24) which are aligned axially with each of two adjacent end faces being provided with a wafer (30). A mirror (40) is embedded between each end face and its associated wafer, the wafer being bonded to the end face of its associated wafer. Optical fiber is disposed in a passageway which extends through each ferrule and through the associated wafer. The ferrules and associated wafers are supported to cause adjacent exposed faces of the wafers to be in predetermined spatial relation to each other. Any gap therebetween may be fixed or may be adjusted by a piezoelectric transducer system (44). The disclosed filter provides rejection ratios which are sufficiently high for frequency discrimination in frequency shift keying systems and for channel selection or switching in wave division multiplexer applications.

Abstract: Apparatus and method for controlling concurrent process access of infrastructures comprising tree structures of complex object nodes of information. The apparatus and method respond to a request of a computer process by selectively applying a tree lock to a node to lock the node and child nodes located in a tree structure of the tree locked node. Subsequently, the process transports the applied tree lock from the node to selected child nodes located in the tree structure of the node thereby freeing the unlocked node and child nodes thereof for subsequent access by concurrently running ones of the processes.

Abstract: The present invention relates to a method for distinguishing between an open conductor and a proper termination of a telephone subscriber loop which is terminated with a telephone which does not conform to the ringer-equivalence standard of the FCC Rules. In this invention a telephone subscriber loop can be tested for an open or for a termination by a customer provided equipment telephone by obtaining a first ratio of the tip-to-ground impedance relative to the tip-to-ring impedance; and a second ratio of the ring-to-ground impedance relative to the tip-to-ring impedance, and comparing each of these ratios relative to a fixed ratio value. If the measured ratios are substantially equal to or greater than the fixed ratio value, the subscriber loop is terminated with a customer provided equipment telephone. The fixed value may be dependent upon the length of the loop and whether or not a maintenance termination unit is present in the loop.

Abstract: In D4 channel banks operating in a DS1 Extended Super Frame (ESF) mode, it is possible for inband yellow alarm bits to corrupt data in applications involving unrestricted use of dataport type channel banks including 64 kilobit clear channel capability. A problem also exists in that the data being received in the ESF framing mode could enulate an inband yellow alarm condition, and cause alarm units in a receiving channel bank to declare a "false" yellow alarm condition. The inband yellow alarm problems are eliminated by inhibiting yellow alarm bits from being inserted into the frames of a DS1 Super Frame format during operation in the ESF framing mode, and by ignoring any possible inband yellow alarm bits being received during operation in the ESF framing mode.

Abstract: Unwanted, monotonic growth of sideband energy is avoided in wavelength-division-multiplexed and frequency-division-multiplexed lightwave communication systems by transmitting adjacent channels approximately 2 nm to 3 nm apart in the normal dispersion regime of the optical fiber for the system and by transmitting each channel more than 0.4 nm below a mean zero dispersion wavelength, .lambda..sub.0, of the optical fiber. Interchannel spacing and individual channel separation from the zero dispersion wavelength are measured with respect to a nominal carrier wavelength for each channel.

Abstract: Apparatus and method for controlling process operations against conceptual structures formed of entities embodied on a complex infrastructure comprising tree structures of complex object nodes. The apparatus and method responds to a process request by selectively locking an entity to lock the entity and a structure of entities dependent on the locked entity. The requested entity lock is implemented on an infrastructure node embodying the entity to enable process access to the locked entity and dependent entities thereof.

Abstract: An electrical distribution system for factories and offices is assembled from prewired modules. The basic module comprises a section of duct of a standard length with electrical feeder wires mounted therein. The wires are bared of insulation at one end and have connectors at the other to receive the insulation-free wire ends of an adjacent module. Some modules may also include prewired branch circuits with circuit breakers and outlets in a variety of configurations.

Abstract: A monolithic integrated photoreceiver comprising a p-i-n photodiode and a heterojunction bipolar transistor is realized in a structural configuration that allows the photonics and electronics to be separately optimized in addition to maintaining materials compatibility. These desirable features are accomplished by growing the epilayers of the photodiode and heterojunction bipolar transistor in a single epitaxial growth run. The p-i-n epilayers of the photodiode are grown first on a non-patterned substrate, followed by the direct epitaxial growth of the heterostructure bipolar transistor over the photodiode structure. Selective wet chemical etching over a portion of the entire structure was used in order to delineate the mesa structures of the p-i-n photodiode and transistor such that no contiguous conductive semiconductor layer exists therebetween.

Abstract: Disclosed is apparatus, exemplarily semiconductor X-ray lithography apparatus, that comprises a novel projection system. In preferred embodiments the projection system is adapted for use with radiation of wavelength below about 30 nm. The system comprises four or more mirrors that form a finite conjugate "optical" system that is telecentric at the short conjugate. The mirrors can be selected such that an essentially flat, diffraction limited image is formed. The image field can be two-dimensional, exemplarily a 10.times.10 mm square, and the resolution over the image field can be higher than 0.25 .mu.m.Exemplarily, the "optical" system comprises, from long to short conjugate, a convex, a concave, a convex, and a concave mirror, with at least two of the mirrors being aspherics. The radius absolute values of the four mirrors are, in the above order and as a fraction of the system focal length, 2.20, 2.59, 2.51, and 2.13 all to within .+-.5%.

Abstract: A vector codebook with an ordered set of vector entries that satisfy a prearranged continuity requirement is used to encode signals. The continuity requirement specifies that consecutively considered vectors may not differ from each other by more than k elements, where k is less than the number of elements in the vectors. In one embodiment, two memories are maintained. One for determining the best codebook vector selection, and one for quantizing the input signal in accordance with the selected vector. Recognizing the possibility that the best ordering possible for a given set of codebook vectors can not satisfy the continuity requirement, the vector codebook arrangement of this invention is enlarged in such a case to include additional vectors that are interposed in the sequence of vectors and arranged to maintain the continuity requirement.

Abstract: Apparatus and method for controlling concurrent process access of infrastructures. Apparatus and method responds to a process request by selectively locking ones of the nodes and enables other processes to concurrently lock ancestral and child nodes located in the tree structure of the locked node independent of the lock applied to the selectively locked node thereby enabling concurrently running processes to write into and read information from the locked nodes.

Abstract: Method and apparatus are disclosed for a programmable multiplexer for converting each of one or more input data signals, with individual data rates, into a second higher data rate signal by mapping contiguously arbitarily assigned Capacity Time Slots (CTSs) in a capacity domain frame to Time Slots in a Time Domain frame (TDTSs) so the TDTSs for each input signal are substantially uniformly spread throughout the TD frame. The programmable multiplexer receives separate input data rate signals which are clock synchronized to the multiplexer clock from separate synchronizers, and maps the capacity domain of the input signals to the time frame format using a 2-step or 3-step digit reverse technique. Both techniques decompose the capacity domain address into predetermined digits from predetermined number bases and then combine the digits to perform a similar computation using the number bases in reverse order.

Abstract: In a telecommunication switching system, an apparatus for automatically converting ISDN codeset and codepoint protocol in messages transmitted to the telecommunication switching system from a plurality of other telecommunication switching systems each using a diffrent ISDN codeset and codepoint protcol than the telecommunication switching system to identify the same data information. All telecommunication switching systems are interconnected by data channels. Further, the apparatus is responsive to another ISDN message generated by the telecommunications switching system for transmission to another one of the plurality of telecommunication switching systems to convert the codeset and codepoint protocol of the other message to the codepoint and codeset protocol of the other one of the plurality of telecommunication switching systems.