Abstract: In order to print an isolated feature having a width W in a photoresist layer using an optical radiation imaging system whose lateral magnification is equal to m, a phase-shifting mask is used having a corresponding isolated feature. In one embodiment this corresponding isolated feature has a central square portion having a refractive index n.sub.1 and a thickness t.sub.1, and a peripheral (rim) square-ring phase-shifting portion having a width B, as well as a refractive index n.sub.2 and a thickness t.sub.2, such that the phase-shift .phi.=2.pi.(n.sub.2 t.sub.2 -n.sub.1 t.sub.1)/.lambda. of the central portion relative to the peripheral portion is equal to .pi. radian or odd multiple integral thereof. The width C of the central portion advantageously is selected such that mC/W is equal to at least 1.2, and preferably greater than 1.5, rather than unity.

Abstract: The effects of polarization dependent hole burning and/or polarization dependent loss are reduced by modulating the state of polarization (SOP) of an optical signal being launched into the transmission path periodically between first and second states of polarization of at least one pair of orthogonal states of polarization. Ideally, the launched modulated signal should spend equal time intervals in both states of the orthogonal pair. In one exemplary embodiment, the SOP is modulated such that it moves along a great circle on the Poincare sphere. In another exemplary embodiment, the SOP is modulated such that it traces a complete great circle on the Poincare sphere. In a preferred embodiment, a complete great circle is traced at a uniform speed on the Poincare sphere.

Abstract: A unified and systematic approach is taken both to design of a virtual communications network within a carrier's telecommunications network, and to design the screening filters provided in the VCN data base which control the admission of calls to the network. For this purpose, telecommunications traffic information that is relevant for both the design of the VCN architecture as well as for development of the screening filters is aggregated and applied both to a network design tool that is used to generate the customer's virtual network configuration, as well as to a screening filter generator (SFG). The traffic information may include, for example, traffic data contained in network and customer premises equipment call detail records and billing data.

Abstract: The invention in one aspect involves a method for repairing an optical system. The optical system includes at least one optical element which comprises, in turn, a substrate having a principal surface, and a multilayer coating overlying the principal surface. The substrate comprises a first material, and the multilayer coating comprises plural second and at least third material layers in alternation. The method includes the steps of removing the multilayer coating from the substrate, and redepositing a new multilayer coating on the substrate. The old multilayer coating is removed in a single etching step while preserving the quality of the principal surface to such an extent that the peak reflectivity of the new multilayer coating is at least 80% the reflectivity of the old multilayer coating.

Abstract: Temperatures along the surfaces of water tubes in an operating steam boiler are determined by detecting infrared radiation emitted from the tube surfaces in one or more narrow pass-bands founds to be available despite the presence of hot and turbulent flue gases between the sensor and the tube surface to be measured.

Abstract: Incidence of breakage in optical fiber drawn from sol-gel produced preforms is reduced by treatment of the still-porous glass by use of a chlorine-containing, oxygen-free gas mixture. Improved satisfaction of proof-rest requirements to at least 100 kpsi is assured by size reduction of unassimilated discrete particles in the fiber.

Abstract: In a method for making optical fiber preforms, the time taken for sintering and annealing the clad or jacket layer is significantly reduced by only partially sintering the jacket soot boule in an atmosphere of helium. For example, instead of using one hundred forty-three minutes to sinter completely the soot boule, the boule is only partially sintered by heating in a helium atmosphere for fifty-nine minutes. At this stage of course, the soot boule is still partially porous and is generally opaque. The completion of the sintering and the annealing is then done in a single step in an atmosphere of nitrogen. Surprisingly, we have found that this process does not entrap nitrogen in the soot jacket layer to any noticeable or harmful extent, and the total time for sintering and annealing is significantly reduced.

Abstract: Timing jitter problems are effectively eliminated in a soliton transmission system realized in accordance with the principles of the present invention by deploying optical filters whose center frequency intentionally differs from the center frequency of adjacent optical filters. The center frequency of the series of optical filters is translated along the desired length of the system in a predetermined manner such as frequency increasing, frequency decreasing, and combinations of both to create a transmission environment which is substantially opaque to noise while remaining perfectly transparent to solitons.

Abstract: A new metallization is described which is a composite of subsequent metal layers beginning with a layer of titanium and having in an ascending order the following composition: Ti--TiPd--Cu--Ni--Au. TiPd is an alloy of titanium and palladium containing from 0.3 to 14 weight percent Pd, by the weight of the alloy. The TiPd alloy is etchable in an aqueous HF solution containing from 0.5 to 2.0 and higher, preferably from 0.5 to 1.2 weight percent HF. The use of the TiPd alloy avoids the occurrence of Pd residues remaining after the etching of Ti layer and lift-off (rejection etching) of Pd layer in a prior art Ti--Pd--Cu--Ni--Au metallization. Ti and TiPd layers are present in a thickness ranging from 100 to 300 nm and from 50 to 300 nm, respectively, and in a total minimum thickness needed to maintain bonding characteristics of the metallization.

Abstract: An integrated circuit is disclosed that includes a biquadratic filter in which the poles and zeroes are independently adjustable. The transfer function of the filter has a pair of zeroes in the numerator and a pair of complex conjugate poles in the denominator. The integrated circuit includes a first circuit for constructing the complex conjugate poles of the filter transfer function. The first circuit has an input port for receiving an input signal and an output port at which an output current representative of a filtered output signal is presented. The integrated circuit includes a second circuit for constructing, independently of the poles, the zeroes of the filter transfer function. The second circuit has an input port coupled to the input port of the first circuit for receiving the input signal. The second circuit includes a differentiator for differentiating the input signal to produce a differentiated input signal.

Abstract: A multiplexer for selecting one of at least two input signals as the output on sensing the change in the state of a select input waits for the clock signal of the active first clock to transition to a predetermined state, disconnects the active first clock from the output of the multiplexer and maintains the output of the multiplexer in the predetermined state while waiting for the clock signal of a second clock to transition to the predetermined state. The second clock is connected as the multiplexer output while the clock signal of the second clock is in the predetermined state. In a preferred embodiment, the predetermined state is a low logic level.

Abstract: A low temperature chemical vapor deposition process is used to encapsulate aluminum conductors on the surface of a silicon substrate to form bimetallic conductors. The refractory material is desirably tungsten.

Abstract: A memory is partitioned into rows and columns of memory blocks comprised of latches, sense amplifiers, and logic circuitry that form independent pipelines through which flow a) input addresses for memory access requests and b) data to be written into a specific memory cell within a memory block. The memory allows multiple data access requests in consecutive clock cycles to be pipelined in the rows and columns of memory blocks such that the memory clock speed is equal to the clock speed of a single memory block, independently of the memory size.

Abstract: A method of arranging outside plant facilities associated with a telephone office is disclosed, in which serving terminals that connect to respective telephone station sets are designated as the originating equipment rather than the telephone office, thereby greatly simplifying the inventory of such facilities. As a result of such simplification, the outside loop assignment of a drop wire is then determined dynamically at the serving terminal.

Abstract: Branchwood signals are generated by a tailbiting convolutional coder. The receiver stores received branchword signals in memory such that the branchword signals are accessible in a logically circular sequence. The receiver then performs Viterbi updates on the logically circular sequence of branchwords, the sequence comprising more than N branchwords. The receiver stops performing Viterbi updates in response to an indication that update decisions have become repetitive. A set of generated decision vectors resulting from the Viterbi updates is then modified in response to the indication. A decoded signal is generated by performing a Viterbi traceback procedure using the modified set of decision vectors. The indication that Viterbi update decisions have become repetitive may be provided by a predetermined fixed number of Viterbi updates, the number reflecting an estimate of when said update decisions will likely become repetitive.

Abstract: A method for use by a switching system in controlling the downloading of parameters to customer stations. The notification of stations due to a change in a configuration group is performed at a controlled rate and accordingly any reduction in call processing due to the parameter downloading of customer stations is limited. The controlled rate notification is performed in accordance with two lists that are maintained by the switching system and used to track the active/inactive status of customer stations and to order the notification of active stations and the status checking of inactive stations.

Abstract: Disclosed is a method for fabricating devices, and the resulting products, using Tape Automated Bonding (TAB) technology. Via holes are formed through a flexible insulating layer, such as polyimide, and are plated through when conductive fingers are formed on one surface of the layer. The resulting structure is then bonded to a semiconductor chip by means of the conductive pads formed on the surface of the insulating layer opposite to the conductive fingers.

Abstract: The use of the JTAG port provides for boundary scan testing of integrated circuits, thereby allowing for the testing of IC's after they have been mounted into a circuit board. However, the conventional JTAG scheme is limited as to speed, since both the input and output vectors must be serially shifted in and out of I/O buffers along the chip boundaries. The present invention speeds the testing of high-speed core logic circuitry by transferring the test program to a special test data register, which downloads the program to the logic circuitry under test, and uploads the results. This allows the core logic to perform the test at its normal operating speed, while still retaining compatibility with the JTAG standard for other tests.

Abstract: This invention relates to a method and apparatus for offering wireless telecommunication service. Pairs of the transceivers of a wireless cell site are directly interconnected. When a request for service is received, a controller allocates a pair of the transceivers to handle the call. If the call is to the public switched telephone network, an unconnected transceiver is connected to a switching system, such as a toll switch, and a protocol converter converts between call control messages to and from the cell site and call control messages to and from the toll switch. If the cell site has directional antennas, a pair of transceivers connected to the directional antennas for serving the calling and called stations is selected; transceivers connected to an omni-directional antenna can be used for overflow traffic and for traffic between the toll office and the cell site.

Abstract: This invention is an inventive N input by L output interconnect fabric. In operation, packets comprising an information field and an address are received at the N inputs to the interconnect fabric, and the address in each packet is mapped to a group of outputs, rather than to any particular output. Each packet is then routed to any available one of the interconnect fabric outputs associated with the group to which the packet is mapped. If a number of packets destined for the same group simultaneously arrive at the interconnect fabric inputs and the group to which they are all destined does not comprise enough outputs to accept them, then all packets in excess of the number that the destined group can accept are simply discarded. The probability of lost .[.jackets.]. .Iadd.packets .Iaddend.due to such discarded packets is acceptably small. In one exemplary embodiment, the invention can be utilized to build arbitrarily large packet switches.