Abstract: An improved storage compartment for batteries and the like is formed by a housing and a compartment door. The housing includes an opening along one edge that is shaped to receive the compartment door. Within the opening are circular supports for holding the compartment door and for permitting rotation of the door into the housing as it is being opened. The compartment door contains a cylindrical shaft at each end thereof for engaging the circular support. When used as a battery compartment, metallic contacts are either mounted in the housing or in the door itself. These contacts make electrical connection with one or more batteries placed into the storage compartment. Within the compartment, batteries are positioned such that the axis around which the compartment door rotates passes through the center of gravity of the batteries.

Abstract: A high speed logic circuit having extremely low propagation delays, suitable for implementation in III-V technology. A logic stage provides the desired logic function by combining a predetermined number of input FETs. The drains of the input FETs couple to a pull-up FET and form a first intermediate output of the logic stage. The sources of the input FETs couple to a pull-down FET and form a second intermediate output of the first stage. A second stage, or buffer stage, responding to the intermediate outputs of the first stage, provides sufficient drive to an output terminal of the logic gate to drive multiple loads (gates) coupled thereto. The second stage includes a pull-down FET responsive to the second intermediate output of the first stage. The second stage also includes alternative combinations of FETs and diodes to pull-up the voltage on the output terminal of the logic gate.

Abstract: A feed forward circuit receives an input signal having at least one carrier therein in a prescribed frequency range. The input signal is applied to a first circuit path having a power amplifier that produces an output signal with a distortion component and to a second circuit path that delays the input signal without distortion. The output signal of the first circuit path is combined with the output signal of the second circuit path to form a signal representative of the distortion component of the first circuit path output signal and the distortion component representative signal is subtracted from the output signal of the first circuit path to cancel the distortion component therein. The prescribed frequency range of the first circuit path output is scanned to detect a carrier signal and the amplitude and phase of the signal in the first circuit path is modified to minimize the magnitude of the detected carrier in the distortion representative signal.

Abstract: In an optoelectronic integrated circuit, an electronic device is integrated with an optical device by fabricating the electronic device directly in a doped semiconductor layer of the optical device. The optical devices contemplated for use include at least a region of multiple low-doped or intrinsic quantum well layers; electronic devices include bipolar and field-effect transistors. Resulting integrated circuits exhibit a high degree of planarity.

Abstract: A deep-UV step-and-repeat photolithography system includes a narrow-bandwidth pulsed excimer laser illumination source and an all-fused-silica lens assembly. The system is capable ofline definition at the 0.5-micrometer level. One significant feature of the system is its ability to perform wafer focus tracking by simply changing the frequency of the laser.

Abstract: An optical power tap is disclosed which allows effectively nonreciprocal injection and removal of power at each node of a single-mode optical fiber local area network. The power tap uses a wavelength-selective directional coupler to inject and remove power from the bus, and a nonlinear converter in the bus to convert light from one wavelength to another. In the specific embodiment disclosed a neodymium-doped silica fiber is used as a nonlinear material to convert light from one wavelength to another.

Abstract: An optical fiber communications system with Raman amplification of the signal radiation comprises a broadband pump radiation source, or, preferably, a multiplicity of pump radiation sources and polarization maintaining optical fiber as the transmission medium. The sources are selected to result in a pump radiation spectrum having individual spectral components such that pump radiation intensity for each spectral component in the desired polarization in the fiber core is less than a critical intensity I.sub.c. In particular, the average intensity of pump radiation in a first spectral interval, centered on any wavelength .lambda..sub.p in the pump radiation spectrum and of width equal to the Brillouin line width of the fiber at .lambda..sub.p, is to be less than that average intensity in the first spectral interval that results in conversion of 10% of the radiation in the first spectral interval to stimulated Brillouin radiation.

Abstract: A coupling (20) for backplane connections of an optical fiber arrangement facilitates superbly alignment of optical fibers notwithstanding blind insertion of a portion of the arrangement. The coupling arrangement includes a housing (70) which has a first end portion (52) and a second end portion (49) and which is mounted in an opening of a panel (32) such that it floats and is capable of three dimensional adjustive movement to facilitate alignment of plugs which terminate optical fibers and which are inserted into opposite ends of a sleeve (84) disposed in the housing. A longitudinal movement of the coupling is facilitated by a compression spring (102) which is disposed about the housing between the backplane and a retaining member (104).

Abstract: A security file system for a portable data carrier provides improved security for the data carrier and for data contained in files in the data carrier. Although the data carrier may be embodied to look and feel much like an ordinary credit card, it contains a computer and a programmable memory with operating power and input and output data provided through a contactless interface. In order to provide security for the data carrier, the security file system on the data carrier includes a stored access code for verifying the identity of an individual attempting to access the data carrier, and an appropriate routine for limiting the number of unsuccessful attempts to access the data carrier. The security file system is also configurable to include select ones of multiple stored access codes for enabling the retrieval and modification of data in corresponding select ones of the files. The routine similarly limits the number of unsuccessful attempts to access these files.

Abstract: An improved Manchester code receiver is disclosed which samples the received signal and subtracts from that sample a previous sample of the received signal delayed by a half-bit time interval. A timing extractor selects sample timing from the central zero crossing of the received signal. The sample time is selected to be a quarter-bit time after the zero crossing time of the received signal.

Abstract: Novel superconductive Pb-substituted oxides are disclosed. The oxides all have layered perovskite-like crystal structure, and manifest superconductivity (R=o) above about 77K. The materials are described by the nominal formula X.sub.2+x M.sub.3-x Cu.sub.2 O.sub.8.+-..delta., where X is Bi and Pb, M is Sr and Ca, 0.ltoreq..times..ltoreq.0.3, 0.ltoreq..delta..ltoreq.0.5, the Pb/Bi ratio is between about 0.2 and about 0.5, and the Sr/Ca ratio is between 0.5 and 2.

Abstract: Disclosed in a compact and inexpensive coaxial connector and jack assembly. The spring member which makes the ground connection to the coaxial cable is designed with sufficient rigidity so that the standard sleeve member surrounding the spring is eliminated.

Abstract: A computer printer stand has a rear surface positioned at an obtuse angle with respect to the bottom surface of the computer printer stand so that a bottom-feeding computer printer and the printer stand can be tipped up from the front into a stable position in which they remain standing on the rear surface of the computer printer stand. In the tipped up position, the bottom feed slot is exposed for ease of inserting the beginning of a new stack of paper.

Abstract: In an optical fiber connector in which each of two optical fibers (21-21) is terminated by a plug (40) having a passageway (41) for receiving an end portion of the optical fiber, eccentricity of one fiber end relative to the other is reduced by causing each optical fiber to be mounted in a specified orientation with respect to its associated plug passageway.

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 moleuclar beam epitaxy procedure using certain critical substrate temperature ranges and a particular cleaning procedure.

Abstract: A solder joint assembly technique applies controlled volumes of solder to pads of both package and substrate. The two units are positioned adjacent each other with the pads and solder deposits mechanically maintained in registration with each other. The assembly is reflowed and the final separation between package and substrate at which the resulting solder joint solidifies is mechanically controlled in order to control a geometry of the resultant solidified joint. The solder volume deposits may assume various forms including spherical bumps and solder paste deposits.

Abstract: A PBX system is responsive to an incoming call which is directed to an adjunct of the system for sending a ringing signal over a station facility to the adjunct. When the adjunct goes off-hook, the system outputs to the adjunct over the station facility multi-frequency tones containing information associated with the incoming call prior to establishing a connection between the adjunct and calling party. The information selects the proper operating mode of the adjunct and provides other call processing information to the adjunct. The adjunct communicates information to the PBX using a switch-hook flash and multi-frequency tones.

Abstract: A bidirectional optical communications system is described using a multiple quantum well structure as both a photodetector and light modulator.