Abstract: Disclosed is a laminated optical device assembly having a template which both restrains an optical device and provides a safe bending radius about which to mount fiber optic cables emanating from the device. The assembly is adapted for field assembly to assist a craftsperson with the placement and protection of fragile fiber optic cables. The template is adhesivey bonded between a bottom and a top to provide a robust assembly which is further incorporated into an optical device housing.

Abstract: A relatively large printed circuit board includes a pair of stiffening members for preventing bending of the board during handling. The stiffening members are disposed along opposite sides of the board and include edge portions abutting against the board side surfaces and forming planar side extensions of the board. The member edge portions adjoin lateral extensions which are off-set from the plane of the edge portions and which lie flat against a substrate major surface and there secured to the substrate. A beam is rigidly secured to the lateral extension of each member by means of spaced apart posts. The beam overlies the lateral extension and functions, in combination with the lateral extension and post, as a lattice-type I-beam.

Abstract: The invention includes an interconnection assembly for coupling optical fibers to respective optical waveguides of an optical integrated circuit (OIC). The interconnection assembly includes an OIC assembly preferably formed by adhering a protective plate to a substrate on which the OIC and its optical waveguides are integrated. In one end of the OIC assembly, ends of the optical waveguides are exposed. Importantly, the protective plate and the substrate have substantially similar thermal coefficients of expansion to reduce or eliminate stresses or strains on the adhesive when the interconnection assembly is subjected to temperature and/or humidity conditions that are different from those under which the interconnection assembly was formed. The interconnection assembly also includes an optical fiber array that houses end portions of the optical fibers.

Abstract: A multi-channel integrated circuit, which includes N processing channels and a functional circuit which is time-shared between each of the N channels for processing data in accordance with a first clock strobe. Also included is a time-division multiplexed bus for providing synchronized data to and receiving synchronized data from said circuit in accordance with a second clock strobe. The data are thereby processed within said shared circuit in synchronization with said first and second clock strobes.

Abstract: A lenslet module configured to receive light from a two dimensional laser array having laser sources disposed in a plurality of rows and columns, comprises a transparent substrate that has a light-receiving surface and a light-emitting surface. A plurality of light-receiving lenslets are disposed on the light-receiving surface of the substrate, such that each lenslet corresponds to a laser source in the laser array. An emitting lens is disposed on the light-emitting side of the substrate, in order to focus light collected by the receiving lenslets at a given focal length located at a distance away from the emitting lens. The light receiving lenses and the light-emitting lens are preferably configured as plano-convex lenses.

Abstract: A speech compression system called "Transform Predictive Coding", or TPC, provides for encoding 7 kHz wideband speech (16 kHz sampling) at a target bit-rate range of 16 to 32 kb/s (1 to 2 bits/sample). The system uses short-term and long-term prediction to remove the redundancy in speech. A prediction residual is transformed and coded in the frequency domain to take advantage of knowledge in human auditory perception. The TPC coder uses only open-loop quantization and therefore has a fairly low complexety.

Abstract: Optical system architectures with improved spatial resolution are provided in which the radiation useful for THz spectroscopy and other investigative procedures can be directionally coupled, in a highly efficient manner, into and out of photoconductive structures such, for example, as dipole antennas. An optical system constructed in accordance with an illustrative embodiment of the present invention comprises a source for emitting radiation in a range of frequencies within from 100 GHz to 20 THz, a coupling lens structure for coupling radiation emitted by said source into free space, at least one collimating optical element for collimating received coupled radiation into a beam having a substantially frequency independent diameter and substantially no wavefront curvature, and a detector for detecting the beam collimated by the at least one collimating optical element.

Abstract: A system and method are provided for automatically computing local pitch contours from textual input to produce pitch contours that closely mimic those found in natural speech. The methodology of the invention incorporates parameterized equations whose parameters can be estimated directly from natural speech recordings. That methodology incorporates a model based on the premise that pitch contours instantiating a particular pitch contour class can be described as distortions in the temporal and frequency domains of a single, underlying contour. After the nature of the pitch contour for different pitch contour classes has been established, a pitch contour can be predicted that closely models a natural speech contour for a synthetic speech utterance by adding the individual contours of the different intonational classes and adjusting the boundaries of these to match the boundaries of the adjacent intonation curves.

Abstract: A communication system where a central module repetitively sends interrogation optical pulses to endpoint modules in order to determine operational state of the endpoint modules and of the two-way communication path to the central module. Those pulses also determine whether the endpoint module wishes to initiate communication with the central office. In the endpoint module, a modulator whose function is to send data from the customer's terminal is arranged to operate in two distinct modes. When it is "powered off", which is when the customer terminal is inactive, it allows central office signals to loop-back to the central office. In this state, the optical pulses sent by the central office serve the function of optical continuity checking. When an endpoint module wishes to establish a connection, i.e.

Abstract: A lightwave communication monitoring system has a monitoring member to which are applied signals extracted from one or more fibers in a transmission system. The monitoring member detects the signal and applies a signal derived therefrom to a control or processing unit. When the strength of the derived signal is below a predetermined minimum, the control unit is adapted to activate a fault location member which applies a fault location signal to the fiber circuit in which the signal, or lack thereof, is transmitted. The system is capable of handling a plurality o fiber circuits simultaneously. In another embodiment of the invention, a test signal is launched on the first fiber, or, simultaneously launched on a plurality of first fibers of fiber pairs, and the test signal is simultaneously extracted from one or more of a plurality of corresponding second fibers of the fiber pairs.

Abstract: An acousto-optic silica optical circuit switch that selectively routes signals to one of two outputs includes a surface-acoustic-wave source and a coupler waveguide structure formed within silica glass. The waveguide structure includes a single mode input section connected to a multimode section connected to first and second single mode output sections. The first output section has a structure capable of accepting power from an optical signal propagating in a first transmission mode of the multimode section, and the second output section has a structure capable of accepting power from an optical signal propagating in a second transmission mode in said multimode section. In operation, RF excitation is selectively provided to the SAW source to selectively cause coupling of the first and second transmission modes in the multimode section.

Abstract: Methods and apparatus are disclosed for maximizing the strength and deformability of dimensionally-reduced in-situ-formed composites. According the invention, the temperature of the composite is maintained at less than its recrystallization temperature as it is dimensionally reduced, such as by drawing it through one or more dies in a wire-drawing apparatus. The drawing speed and other parameters may be adjusted, as required, to control composite temperature.

Abstract: At the reception site of a laser transmission system the received laser light beam is converted into a focusing cone of light. The cone of light is directed to partially illuminate the inner area of the quad photo detector array which is used to provide a highly accurate positional measurement of the laser beam. A quad photo detector is utilized to measure deviation of the laser beam from its ideal line-of-sight and provide sensing signals defining the deviation to enable its corrective adjustment. A high speed photo detector located centrally to and behind a central aperture of the quadrant photo detector permits the detection of the laser light beam voice and data.

Abstract: Digital streams are converted into analog signals for recording by analog recorders, such as conventional video cassette recorders, onto analog storage media, such as conventional video cassette tapes. The recorded analog signals are then retrieved from the analog storage media using an analog player, such as a conventional video cassette player, and converted back into the original digital streams. The present invention allows conventional analog-based recording and playing equipment, like video cassette recorders/players, to be used for storing and retrieving digital data. In one embodiment, the digital streams correspond to digital audio/video data and the retrieved digital streams can be further processed to playback the audio/video streams using conventional television sets. In other embodiments, the digital streams correspond to other digital data streams that can be converted into analog signals for storage and retrieval using conventional video cassette recorders and conventional video cassette tapes.

Abstract: A switch for selectively cross-coupling first and second input lines to first and second output lines. The switch includes: (1) a waveguide having a cavity for containing signals, (2) first and second wireless transmitters that radiate signals received from the first ands second input lines, respectively, within the cavity, (3) first and second wireless receivers that selectively receive the signals from the cavity and provide the signals to the first and second output lines, and (4) a switch controller that controls the at least some of the first and second wireless transmitters and receivers. The first and second input lines are selectively couplable to the first and second output lines. The waveguide, wireless transmitters and wireless receivers cooperate to provide a fabricless cross-connect within the switch.

Abstract: A method and apparatus for generating region frames from video frames are disclosed which employs an industry standard encoder to lessen the negative impact on the quality of the transmitted video sequence while consuming fewer bits. The method and apparatus utilizes image segmentation and color replacement techniques to create the region frames. Each region frame includes a subject region, zero or more previously segmented regions and zero or more non-subject regions. The subject region is defined by the pixels of the original video frame. The previously segmented regions and non-subject regions are assigned replacement pixels P.sub.n,y and C.sub.n, respectively. The replacement pixel C.sub.n is chosen to indicate a color that is not likely to be confused with any color in the subject region R.sub.n. The replacement pixels P.sub.n,y are chosen such that the compression ratio of the region frame data is maximized.

Abstract: A reduced complexity maximum likelihood multiple symbol differential detector which utilizes a maximum likelihood sequence estimation of the transmitted phase and does so by expanding the observation window to observe the received symbol over N signal intervals and making a simultaneous decision on N-1 symbols. The phase of the received signal is calculated up front and thus the detector requires only real subtractions and real additions as opposed to complex multiplications and additions. Furthermore, the detector does not sacrifice performance over conventional prior art detectors.

Abstract: Pseudo two-dimensional hidden Markov models (HMMs) are used to represent text elements, such as characters or words. Observation vectors for each text element are based on pixel maps obtained by optical scanning. A character is represented by a pseudo two-dimensional HMM having a number of superstates, with each superstate having at least one state. Text elements are compared with such models by using the Viterbi algorithm, first in connection with the states in each superstate, then the superstates themselves, to calculate the probability that a particular model represents the text element. Parameters for the models are generated by training routines. Probabilities can be adjusted to compensate for changes in scale, translations, slant, and rotation.An embodiment is also disclosed for identifying keywords in a body of text. A first pseudo two-dimensional HMM is created for the words that may appear in the text.

Abstract: A method for forming, and an arrangement for using arbitrary angle mirrors in substrates is disclosed. An erodible material, such as a photoresist, is applied to a substrate at a site and is exposed to radiation at that site which has a linear variation in energy at the surface of the erodible material. Due to this variation in exposure energy, a taper results in the erodible material after development. The tapered region is then etched in a manner which etches both the erodible layer and the underlying substrate. The taper in the erodible layer provides a varying attenuation during the etching process such that the taper of the erodible layer, or a multiple of it, is transferred to the substrate. In a first embodiment, a tapered reflective surface is formed in a substrate, which surface engages an optical signal and deflects it to an optical device or another surface.

Abstract: An improved squeeze-type micromechanical structure for high speed operation, i.e., greater than 1 MHz, is disclosed. The structure has a movable member possessing damping holes. The porosity, 1/(.omega..sub.o .tau.), of the movable member is at least about 1.4. The structure is hermetically sealed and is maintained above atmospheric pressure and at a minimum reduced pressure or gas frequency, .omega..sub.g /.omega..sub.o, of about 1.3. To operate with less than 10 percent "ringing," .omega..sub.g /.omega..sub.o >1.3 and 0.25+0.7(.omega..sub.g /.omega..sub.o).sup.2 -0.8(.omega..sub.g /.omega..sub.o -1.25).ltoreq.1/(.omega..sub.o .tau.).ltoreq.0.25+0.7(.omega..sub.g /.omega..sub.o).sup.2 +(.omega..sub.g /.omega..sub.o -1.25).