Abstract: The present invention is a method for making multi-quantum well structures having superior interfacial crystalline quality. In particular, it is an LP-MOCVD crystal growth method using continuous growth stages to produce well-defined heterojunctions of uniform thickness for multi-quantum well (MQW) lasers, including MQW lasers structures having output wavelengths less than approximately 1.55 .mu.m. The continuous growth stages are characterized by essentially instantaneous gas switching sequences from a first gaseous mixture used to grow separate confinement layers (SCL) and barrier layers to a second gaseous mixture used to grow quantum well layers. By continuous growth stages it is meant that there is no intentional pause between well and barrier layer growth stages, that is, the gaseous mixture used for a particular growth stage is introduced into the LP-MOCVD reactor just as the last of the previous gaseous mixture is venting out of the reactor.

Abstract: A telephone ringing system in which one or more user-selected sound segments are received using the microphone portion of a telecommunications instrument, stored in digital or analog form, and audibly reproduced using the loudspeaker portion of the telecommunications instrument when a ring signal is detected to provide a distinctive, personalized indication of an incoming call.

Abstract: A power factor correction system with an EMI input filter includes circuitry to sense the capacitor current of the filter to improve the accuracy of the power factor enhancement by providing a split current sensing resistor connected to the EMI filter or a voltage sensing capacitor. Both arrangements may be tightly coupled to the current control loop of the power factor control and compensate for the unsensed current in the EMI filter capacitors.

Abstract: A method and apparatus for separating one or more optical fibers from an optical fiber ribbon is disclosed by the present invention. This device includes a housing with a base and a cap, the base providing support for the optical fiber ribbon and the cap providing a slotted member for exerting lateral force on the ribbon to separate one or more fibers therefrom without damaging the separated fibers or compromising the integrity of the remainder of the ribbon.

Abstract: An optical shutter for use with optical fiber connector coupling adapters has a front, transverse face which is sufficient to cover the opening in the adapter. The transverse portion has a pair of pivot arms extending from either side thereof which are adapted, at their distal ends, to be pivotally connected to the coupling adapter, thereby providing a pivotal mounting for the shutter. The transverse face also has a flange extending from one end thereof to permit actuation of the shutter, i.e. opening or closing, by means of the connector to be inserted in the adapter, or after removal of the adapter.

Abstract: A splice housing assembly for joining together at least two fiber optic cables. The splice housing assembly has a housing adapted to create a water impervious seal around both a splicing chamber and at least two fiber optic cables that lead into the splicing chamber though the housing. Within the splicing chamber, the various fiber optic cables are joined together via a grounding block or by a direct optical splice. The housing provides structural integrity, electrical insulation and water tightness to the splice, yet the housing can be selectively opened and closed. As a result, any splice can be made and tested, then repaired or adjusted before the housing is permanently sealed with an encapsulation compound.

Abstract: An apparatus minimizes the spherical aberration of a light beam emitted into an optical fiber from a light source such as a laser beam. The laser emits a light beam along a path of travel to an optical fiber used in a telecommunication system. A ball lens is positioned within the light beam path of travel, and has a front focal point. The laser is positioned in front of the front focal point such that the light beam emitted by the laser forms an intermediate paraxial focus point. A corrective lens is positioned adjacent the paraxial focus point so that the laser beam is introduced into an optical fiber with minimal spherical aberration and increased coupling efficiency. The corrective lens is displaced radially off-center to compensate for misalignment aberrations and coma.

Abstract: A method and apparatus for determining the limit on learning machine accuracy imposed by the quality of data. A plurality of learning machines of increasing capacity are trained using training data and tested using test data, and the training error rates and test error rates are calculated. The asymptotic error rates of the learning machines are calculated and compared. When the change in asymptotic error rate falls below a certain rate, the asymptotic error rate estimates the limit on learning machine accuracy imposed by the data.

Abstract: The invention is an operational amplifier having an output stage for enhancing the output driver capability near the negative source voltage. The output stage of the invention includes a voltage detector in combination with a current redirector or redirecting arrangement. The voltage detector converts the voltage difference between the amplifier output and the input to the output stage of the amplifier to a control current, which is redirected at the positive source voltage and applied to the negative output driver. The current redirector, which is operably connected to the voltage detector, allows the amplifier output to be driven at full rated current (e.g., approximately 40 mA) close to the negative source voltage (e.g., within approximately 1.5 volts) while maintaining an output configuration appropriate for stability.

Abstract: An optical modulator/optical switch is disclosed. The modulator/switch includes a reflective zone plate defined in a movable zone plate support. The reflective zone plate focuses an optical signal reflected therefrom. In response to a control signal, a controlled voltage source applies a voltage across the movable zone plate support and a layer spaced from the zone plate support. The applied voltage generates an electrostatic force that causes the zone plate support to move towards the other layer. When the zone plate support moves, the reflective zone plate's orientation to an optical signal incident thereon changes. Such a change in orientation alters the path of the optical signal reflected from the reflective zone plate. The reflected optical signal can be directed to different receiving waveguides by changing the amplitude of the applied voltage.

Abstract: A method of forming a via hole in a substrate includes forming an opening in a substrate thereby forming a slag and then heating the substrate to recombine the slag with the substrate.

Abstract: A barrel plug for an insulated electrical cable, a power cord and a method of manufacturing the barrel plug.

Abstract: A stackable splice module adapted to engage and mount to additional stackable splice modules to form an electrical connector for pairs of wires, the stackable splice module including an upper portion and a lower portion. A series of indexing teeth are formed along the length of the upper portion, defining wire receiving passages therebetween. Contact elements are mounted within the stackable splice modules, each having an upper end that projects into the teeth of the upper portion of its stackable splice module. The contact elements each include a wire receiving slot aligned with a wire receiving passage of the upper portion and which engages in the insulated wires to establish contact therewith. Lower ends of each contact element project into the lower portions of the splice modules and each include contact slots adapted to engage and receive a contact member of an upper end of a contact element of an additional splice module being stacked thereunder.

Abstract: The disclosed method of making a semiconductor device comprises a screening procedure that facilitates identification of devices having relatively low flicker noise. The devices are typically semiconductor diodes. The procedure utilizes our discovery of a correlation between the reverse bias current I.sub.r of a semiconductor device and the flicker noise power, and comprises measurement of the reverse bias current and comparison of the measured value with a predetermined comparison value I.sub.rc. Devices having I.sub.r .ltoreq.I.sub.rc are those that have relatively low flicker noise. The screening procedure is simple and quick, and can be readily performed in a manufacturing environment.

Abstract: A modular switch box which is responsive to a control signal, is diagnosable, and is not dependent upon the type of protocol being switched. There may be a plurality of switch boxes wherein each switch box includes a plurality of inputs and an output. There is a selector for selecting which input is connected to the output and a controller for controlling the selector. There is also a control means for controlling the switch boxes. The switch boxes are connected in a chain so that the input of one switch box is connected to the output of the next, etc., until the output of the last switch box is connected back to the controller. The controller sends a command message to the first switch box which then executes the command and forwards the message on to the next switch box, etc., until the command returns to the controller. In this manner, the controller knows that all switch boxes have received the command.

Abstract: A buffered optical fiber (20) includes an optical fiber (21) comprising a core and a cladding. Typically, the optical fiber is enclosed by at least one layer (23) of coating material. The optical fiber is enclosed by a plastic buffer layer (30). Interposed between the optical fiber and the buffer layer is a boundary layer (40). Importantly, the boundary layer of the present invention is a low modulus material applied as a substantially thick layer relative to the buffer layer. In a preferred embodiment, the wall thickness of the boundary layer is about one-forth to one-third the wall thickness of the buffer layer. However, depending on the particular materials selected for the buffer and boundary layer, the wall thickness of the boundary layer can be as thin as one-twenty-fifth (1/25) of the buffer layer.

Abstract: The invention provides a remote access telephone system that includes a telephone station which has two access numbers. The remote access telephone system responds to a first one of the two access numbers by providing remote access features and responds to a second one of the two access numbers by providing normal access features. The remote access telephone system also includes a remote access controller that prevents a remote caller from having access to the telephone station unless the remote caller dials a valid password. The remote access features includes remote dialing a number recalled from a directory memory based on a second party name spoken by the remote caller. A remote directory feature is provided when the remote caller speaks a remote directory command and a name. The remote access controller recalls a number corresponding to the name and outputs the number to the remote caller.

Abstract: A wireless Local Area Network (LAN) includes a repeater which a) synchronizes interface adapters for portable end-user devices and b) retransmits data signals received which retimes and retransmits data signals received from these end-user devices that gain, one at a time, the exclusive right to transmit those signals during a given transmission time subframe by contending for access to the LAN resources that are auctioned off to permit LAN resource utilization that is independent of traffic load and that is implemented in a near collision-free environment.

Abstract: A fabrication technique for improved dielectric isolation of adjacent, electronic devices or electrically controllable optical devices provides an inter-device resistance in excess of 1 M.OMEGA.. Strips of a silicon oxide material, such as SiO.sub.2, are formed between the devices after device formation but prior to regrowth of an electrically conductive cap layer and subsequent metallization. The presence of the SiO.sub.2 strips prevents regrowth of the cap layer between the adjacent devices.

Abstract: An improved method and apparatus (12) for handling calls in a call center predicts (206, 312, 410) a caller's level of motivation for making the call and uses (208-212, 314-330, 412-416) the prediction as a basis for determining how to handle the call. The method and apparatus respond to a call coming in to the call center by determining (206, 306, 404) a number of call attempts--either all call attempts whether answered or unanswered by an agent, or only unanswered call attempts--made by the caller to the call center within a predetermined elapsed period of time, and possibly also by determining (308-310, 406) other predictors of the level of motivation of the caller in making the call, prior to the call being answered.