Abstract: A reflection filter is disposed on a solid state laser so as to preferentially reflect TE or TM modes and to suppress oscillation within the resonator of the non-reflected modes. In one embodiment, the filter includes a layer having a plurality of grooves which may be straight and parallel or curved to approximate the mode shape. In another embodiment, the filter includes a polarization sensitive film, without grooves, which either absorbs or transmits the undesired mode. Specifically described is a buried heterostructure semiconductor DFB laser with such a reflection filter formed on at least one facet thereof.

Abstract: A high resolution image is decomposed to a basic lower resolution replica and a plurality of supplemental information fields for use in a progressive high resolution image facsimile transmission system. The basic lower resolution replica is generated by successive decompositions of the original image into a plurality of intermediate lower resolution replicas and corresponding supplemental information fields by employing a so-called edge decomposition technique. The supplemental information fields are required in a receiver to upgrade the basic lower resolution replica toward the original high resolution replica.

Abstract: A repertory telephone dialer includes a memory for storing two telephone numbers and one telephone call payment number. Activation of a switch on the dialer causes the first telephone number to be dialed; thereafter, the dialer responds to a Calling Card Service-Prompt Tone by transmitting the call payment number. The call payment number corresponds to a credit card number of the party to be billed for the call. The dialer is constructed as an adjunct device that connects to an existing telephone set by merely rearranging cords. Included on the front surface of the dialer is a recessed area that accommodates a photograph or graphic rendering of the party whose telephone number is dialed and who typically makes payment for the call. Activation of another switch on the dialer inhibits the remote billing feature by causing the second telephone number to be dialed.

Abstract: A waterproof cable having a filling material for filling voids in the cable which comprises a styrene-rubber diblock copolymer, a styrene-rubber-styrene triblock copolymer a paraffinic oil, a polybutene oil and a polyethylene wax. The cable is suitable for aerial use as well as underground use.

Abstract: Currently, metallic loops are tested for shorts, opens and grounds by applying a test signal (DC or 20 Hz) directly to the metallic looop. A test signal cannot be applied to any part of the network other than the metallic loop because it will be blocked by the A-to-D converters and the hybrid of the system before it can reach the metallic loop.In this invention, digital signal processing is used to test a metallic loop for shorts, opens, grounds and the presence of loading coils from a remote location. Direct metallic connection to the metallic loop is no longer necessary.Briefly, a test signal, in digital form, is fed into the network at some convenient location remote from the metallic loop that is to be tested. As the signal passes through the A-to-D converter from the digital section of the network to the analog metallic loop, it is converted by the A-to-D converter into an analog signal having a specific frequency and a predetermined amplitude.

Abstract: Certain semiconductor device structures are described in which single crystal layers of cubic Group II fluorides cover at least part of the surface of III-V semiconductor compound. The Fluoride crystal has a cubic structure and may be lattice matched or lattice mismatched to the compound semiconductor substrate depending on fluoride composition. These fluoride single crystal layers are put down by a molecular beam epitaxy procedure using certain critical substrate temperature ranges and a particular cleaning procedure.

Abstract: The present invention relates to an optical backplane for use in a switching system or computer for interconnecting a plurality of associated circuit modules. The backplane comprises a switch which is interconnected to each of the associated circuit modules by a separate multifiber ribbon, each ribbon including (1) a plurality of transmit and receive optical fibers, and (2) an optical fiber for providing concurrent synchronization signals to each of the associated circuit modules. The switch includes a switching block for coupling parallel optical signals received from the plurality of receive optical fibers in any multifiber ribbon, transmitted by a sending module, to the transmit fibers of each of the multifiber ribbons for transmission to all of the modules associated with the optical backplane.

Abstract: A method has been developed for altering the resistivity of selected regions (tubs) in a dielectrically isolated (DI) wafer. Subsequent to the formation of the conventional tub structure, the wafer is patterned and etched to expose selected tubs. These tubs are then etched and selectively implanted and an epitaxial layer of a new resistivity value is grown in the empty tube regions. The resistivity of the epitaxial material may be chosen to alter the conductivity of the selected tub regions.

Abstract: In a voiceband data multipoint network, each tributary modem transmits, in a trailer which follows the user data, a tributary modem identification, a sequence number which advances for each start-up and a checksum. The observation at the receiver of a gap in the series of sequence numbers in messages determined to have originated from a particular tributary modem is used to accurately compute a missed message rate for that modem.

Abstract: Excellent ordering in ferroelectric liquid crystal devices is obtained by utilizing a material having a smectic C phase and no higher temperature orthogonal smetic phases. Ordering is accomplished by the combination of (1) contacting the liquid crystal material in the smectic C phase with an ordering substance and (2) subjecting the liquid crystal material to a slowly varying electric field.

Abstract: A communications cable comprising a core of at least one transmission medium and a plastic jacket includes provisions for preventing the movement of water within the cable. An impregnated tape (35) is interposed between the core and the jacket and is wrapped about the core to form a longitudinal overlapped seam. The tape comprises a substrate tape (37) which is impregnated with a superabsorbent material which upon contact with water swells and inhibits the further movement of the water. The tape and its thickness are controlled so that the thickness is minimal while the tensile strength of the tape and its porosity prior to impregnation are optimized.

Abstract: The nonlinearity of the frequency response of a solid state power amplifier (SSPA) is obviated by effectively operating the SSPA at the 1 dB compression point, where the nonlinearity does not exist, and controllably reducing, downstream of the SSPA, the power output produced by the SSPA to the level required by the link. In particular, the output is reduced by controllably inserting a relatively thin tapered blade of ferrite material into a waveguide coupling section downstream of the SSPA. Preferably the ferrite material is comprised of a robust carbonyl steel of sufficient thickness to withstand the heat induced in the course of its absorbing microwave energy at the SSPA output, while being of a narrow or thin configuration and oriented for insertion into the absorbing section of waveguide so as to not effectively alter the characteristics of the signal profile of the electromagnetic wave.

Abstract: A hydrogen-free boron-containing membrane in tension exhibits advantageous properties for use as a mask in X-ray lithography.

Abstract: Disclosed is an optical fiber connector useful for high density arrays. A rotating mechanism is employed around the fiber ferrule in combination with a spring so as to engage one or more tabs on the connector sleeve. The rotating mechanism includes a serpentine type groove configuration which captures the tabs when the ferrule is pushed into the sleeve and releases the tabs when a longitudinal force is again applied to the ferrule.

Abstract: Spliced end portions (30-30) of two optical fibers are recoated in a manner hich results in the cross section of the spliced length of fiber transverse to a longitudinal axis thereof being substantially constant. This is accomplished without compromising the adhesion of a curable recoating material (51) to an adjacent original coating material (38). In order to provide such a recoated portion, original coating material which is removed to permit splicing is removed in such a manner as to leave a tapered portion (52) remaining on the end portion of each optical fiber. As a result, the interface between the recoating material and the original coating material is increased sufficiently to avoid having to overlap some of the recoating material with original coating material on adjacent portions of the fibers being spliced.

Abstract: A circuit package comprises at least one IC chip bonded directly in a hole provided in a wafer such that the surface of the chip and the surface of the wafer are in the same plane thereby accommodating TAB bonding of the chip to bonding pads provided on the wafer. The structure can include multilayer circuitry on the wafer.

Abstract: An actuator including a device made of thin film shape memory material mounted to a substrate. The thin film device is deformed from its original shape. Thereafter, the device is heated to restore the device to its original shape. Motion of the device occurs in the deforming and restoring steps, which is used to produce some form of work result.

Abstract: A switching mode converter with current mode regulation includes a passive network operative to waveshape a ramp signal in order to attenuate the leading edge spike of the sensed switch current. A passive pulse generating network generates a pulse in response to the generated ramp with the proper timing and polarity such that when superimposed on the sensed current waveform effectively cancels the leading edge spike of that waveform.