Abstract: Conventional optical gratings are relatively temperature sensitive. This sensitivity is generally undesirable but can be reduced or eliminated by attaching the grating to a support member having a negative coefficient of thermal expansion. Exemplarily the member comprises Zr-tungstate and/or Hf-tungstate. The thermal expansion can be tailored by admixture of positive expansion coefficient material (e.g., Al.sub.2 O.sub.3, SiO.sub.2) to the negative expansion coefficient material (e.g., ZrW.sub.2 O.sub.8), or by a variety of other techniques.

Abstract: In a preferred embodiment, an FM demodulator includes an I and Q sampler for generating data samples of I and Q signals of an FM signal. A signal processor derives samples of a modulating waveform of the FM signal from the I and Q data samples, using a Lagrangian interpolation function of the I and Q data samples. Variables include derivatives of the I and Q signals obtained by differentiation of the Lagrangian function. Preferably, the processor further utilizes a correction factor to correct the modulating waveform samples obtained from the Lagrangian-based interpolation, to thereby derive a modulating waveform exhibiting low signal distortion.

Abstract: A circuit for, and method of, reducing cross-coupled interference between first and second telephone lines of a multi-line telephone instrument and a telephone instrument containing the same. The circuit includes: (1) a first differential input amplifier having first tip and ring inputs coupled to conductors of the first telephone line and first tip and ring shunt resistors coupling the first tip and ring inputs to a signal reference of the telephone instrument and (2) a second differential input amplifier having second tip and ring inputs coupled to conductors of the second telephone line and second tip and ring shunt resistors coupling the second tip and ring inputs to the signal reference, the first and second tip and ring shunt resistors decreasing a common mode input resistance of the first and second differential input amplifiers, thereby attenuating cross-coupled interference common to both of the first and second telephone lines.

Abstract: An optical probe microscope includes an optical fiber oriented in a vertical direction. The fiber has a tip that emits light onto a horizontal surface of a sample to be measured. This surface can have both desired and undesired departures from planarity. An electromechanical device for imparting dither motion to the fiber tip is superposed on another electromechanical device for imparting two-dimensional horizontal scanning motion to the fiber tip. The dither motion has a much higher frequency than that of the scanning motion. Between successive scannings, another device moves the sample itself from one horizontal position to another. A microscope receives the optical radiation either transmitted or reflected by the sample surface. The microscope forms a (magnified) image of this received optical radiation on the surface of an optical image position detector. The surface of this detector has a relatively large area compared with that of the (magnified) image.

Abstract: Some embodiments of the present invention are capable of reducing the dynamic range of multicarrier signals. In an exemplary embodiment, the multicarrier signal processor includes a controller configured to receive at least a portion of a multicarrier signal, the controller analyzing the signal to identify at least one carrier signal of the multicarrier signal to be modified. At least one signal modifier communicates with the controller, the signal modifier receiving at least a portion of a multicarrier signal. The signal modifier isolates a carrier signal to be modified as directed by the controller, and modifies the isolated carrier signal. A negative delay is imparted to the carrier signal. A signal combiner receives the modified carrier signal and combines it with an unmodified multicarrier signal. Preferably, the multicarrier signal processor is used to reduce the dynamic range of a multicarrier signal.

Abstract: The present invention provides a multicarrier signal processor capable of reducing the dynamic range of multicarrier signals. In an exemplary embodiment, the multicarrier signal processor includes a controller configured to receive at least a portion of a multicarrier signal, the controller analyzing the signal to identify at least one carrier signal of the multicarrier signal to be modified. At least one signal modifier communicates with the controller, the signal modifier receiving at least a portion of a multicarrier signal. The signal modifier isolates a carrier signal to be modified as directed by the controller, and modifies the isolated carrier signal. A signal combiner receives the modifier carrier signal and combines it with an unmodified multicarrier signal. Preferably, the multicarrier signal processor is used to reduce the dynamic range of a multicarrier signal.

Abstract: A calibration and measurement system for a multi-axial device is disclosed which includes a memory for storing a set of test measurement values obtained from the multi-axial device in a substantially uniform field; and a calibration transformation generator for generating from the set of test measurement values to calibrate the multi-axial device, with the set of test measurement values lying on a multi-dimensional surface.

Abstract: A device and method for connecting an optical switch to the optical fibers that terminate on a fiber distribution shelf within a fiber administration system. The optical switch device contains a support plate that is shaped essentially the same as the protective cover of fiber distribution shelf. As such, the support plate of the optical switch device can be joined to a specific fiber distribution shelf by substituting the support plate for the protective cover. An optical switch is affixed to the support plate, wherein the optical switch is sized not to extend beyond the peripheral boundaries of the support plate. As a result, when the support plate is placed over a fiber distribution shelf, the optical switch joined to the support plate does not obscure any other fiber distribution shelf in the fiber administration system.

Abstract: A contactless interface for transfer of data between a semiconductor music chip and a solid state audio player Data is transferred between the chip and audio player by way of a capacitive interface. The interface comprises a set of conductive plates or electrodes with outer dielectric surfaces on both the music chip and the audio player. Corresponding capacitive plates on the music chip and audio player facilitate data communication by forming a series of capacitors once the music chip is inserted within the audio player so that the capacitive plates of each device are aligned and in close proximity with one another. In accordance with one aspect of the invention a set of four capacitive plates is included on both the music chip and the audio player forming four capacitors. In this arrangement, two plates on each device are utilized to transmit data and two plates are utilized to receive data.

Abstract: An adaptive postfilter is used on the decoding side of tandem codecs (coder/decoders). Post-filter parameters are adapted using a backward synthesis filter. The parameters used are 10th order LPC (Linear Predictive Coding) predictor coefficients. The system employed uses Low-Delay Code Excited Linear Predictive codecs (LD-CELP).

Abstract: The regression testing of a recompiled main software program is provided a facility which performs a limited regression test that has the same level of testing as if the main program were tested using an expanded regression test that tests virtually all of the software modules forming the program. More particularly, if an error is found in the main program it is documented in a modification request which a programmer thereafter uses to track down and identify the software module(s) that needs to be modified to deal with the error. At that point, the programmer modifies the identified software module and also designs a current test program to test the recompiled program to determine if the error has been corrected and that the modification does not affect some other aspect of the program. The modified module and test program are then associated with an identifier identifying the associated modification request.

Abstract: An improved Bragg grating for an optical waveguide comprising a core and a cladding. The grating includes refractive index perturbations formed within the waveguide. It has a bandwidth in reflection having a full width at half-maximum greater than 12 nm, a total intrinsic optical loss less than 0.2 dB, and a total peak optical extinction, measured in transmission, greater than 20 dB.

Abstract: A direction sensor is provided in an automatic control circuit which is incorporated into a distortion reduction circuit. The direction sensor is comprised of a test switch, first and second storage devices, a comparison device, a normalization device and a sampling control device. The direction sensor conducts a series of consecutive test cycles, comprised of even numbered test cycles and odd numbered test cycles, and during each test cycle a sample of the test signal is taken. During the even numbered test cycles the sampling control device causes the test switch to transfer an even numbered sample of the test signal to the first storage device and thereafter to the first input of the comparison device, where the even numbered sample is compared with an earlier in time odd numbered sample at the second input of the comparison device. The comparison device produces a first comparison signal indicative of the relative value of the samples.

Abstract: An integrated circuit counter is capable of implementing a relatively high count while being testable using a relatively low number of clock cycles. A linear-feedback shift register (LFSR) having n bit positions is used as the counter. The feedback path of the shift register includes an exclusive OR (XOR) gate that couples selected bits back to the input of the register, in order to implement a 2.sup.n -1 counter. Combinatorial logic circuitry is included to test the counter in significantly less than 2.sup.n -1 clock cycles. This allows for implementing a testable "watchdog timer" that may be used to detect software runaway conditions in microprocessor systems, among other uses.

Abstract: A passive optical network is provided that spectrally slices optical signals transmitted in both upstream and downstream directions utilizing wavelength division multiplexing routing. The passive optical network preferably includes an incoherent signal source at both ends to provide signals that are spectrally sliced according to optical frequency. The downstream information may be transmitted in a conventional data format. The upstream transmissions may be segregated by subcarrier multiplexing, time scheduling or wavelength division multiplexing. A broadcast signal can be overlayed with point-to-point information for transmission to plural network units.

Abstract: An n-channel field-effect transistor is fabricated utilizing a thin-film fullerene (for example, C.sub.60) as the active element. The fullerene film is deposited onto a device substrate in an ultra-high-vacuum chamber and is thus substantially oxygen-free. Subsequently, while still in the chamber, the fullerene film is encapsulated with a material that is impervious to oxygen.

Abstract: A system for creating still image or video collections for guests of amusement parks and the like a) identifies individuals by a unique tag assigned to the individual, b) automatically records the images of the individuals while they are at various attractions, c) collects the images over a communications network, d) arranges the images in a collection, and e) presents a personal set of collected images to the guest. For example, cameras may be located throughout an amusement park. Each guest is associated with a unique identifier. This identifier may be contained within a readable tag, e.g., a card, badge or pendant. Tag readers identify guest when they are at a particular location and provide identification and location information to a control system. A communications network is used to interconnect the cameras, tag readers, control system and image recording devices. The control system controls the recording and storage of the appropriate image(s) associated with that guest.

Abstract: Convergence of blind fractionally spaced equalizers is improved, and misconvergence is corrected by training the equalizers to detect convergence of one adaptive filter, copying the tap weights of the converged adaptive filter to the other adaptive filters and shifting the tap weights of the other adaptive filters according to the expected phase difference between the respective filters. In a two-dimensional orthogonal modulation scheme the converged weights of a first filter are copied to a second filter and shifted .pi./2. For the two dimensional orthogonal modulation scheme, the probability of a proper convergence can be increased by choosing initial tap weights for the two adaptive filters with a 3.pi./4 phase difference.

Abstract: An assembly for protecting the active electronic components of an electronic product from the environment and electromagnetic interference (EMI). A method is described where the assembly is formed by providing a metallized flexible enclosure around the electronic product, such as a printed circuit board, and subsequently sealing the metallized flexible enclosure, such that separable connectors can be readily accessed without violating the integrity of the seal. The metallized flexible enclosure includes multiple layers of polymeric materials that provide diffusion barrier properties and a metallic layer that provides both diffusion barrier properties and EMI shielding capabilities. The multiple layer sheet is patterned to optimize the diffusion barrier properties and EMI shielding capabilities. Further, the multiple layer sheet enables efficient, high volume production.

Abstract: A high bandwidth gateway comprises a source of packet traffic wherein received packets are stored in a buffer, a destination interface circuit for the packets, a microprocessor and a bus that interconnects the components. The microprocessor, which in the prior art controls data transfers, periodically gives up control to a hardware assist engine. The hardware assist engine detects the presence of packets in the source buffer and causes the source buffer to output one or more packets to the destination directly, thus by-passing the microprocessor completely. By this system, bandwidth is improved by the source and the destination working together directly, without having the overhead associated with microprocessor-based or initiated data transfers.