Abstract: A method and apparatus for monitoring and testing the operation and configuration of a remote receiver in a utility management system, such as a load management system or a cable television subscriber control system. The receivers are responsive to encoded command signals to perform utility control functions such as remove electrical loads from the electrical distribution system or connect a subscriber to the CATV system. The receiver retrieves status information pertaining to the receiver, and transmits the status information over a data communications link to a hand-held operator display unit. The operator display unit receives the transmitted status information, and displays the received status information to the operator on a display.

Abstract: A communications network is implemented utilizing a transmission medium and a plurality of Network Interface Units passively coupled thereto. Communications among a first set of Network Interface Units is implemented on a predetermined channel in a first portion of the transmission medium. Simultaneous communications among a second set of Network Interface Units is implemented using the same predetermined channel in a second portion of the transmission medium. Interference between communications in the first and second portions does not occur because the passive couplers disposed between the portions attenuate the signal from each portion to a value less than a predetermined Network Interface Unit sensitivity level before the signal reaches the other portion.

Abstract: An interconnect fabric is constructed from a plurality of fixed wavelength transmitters which are used to transmit arriving data packets through a star coupler, and a plurality of tunable receivers which tune to whatever frequency necessary to receive the desired data from the star coupler. A control network, constructed from a plurality of fixed wavelength receivers and a plurality of tunable transmitters, determines what frequencies the tunable receivers should tune to, and sends a signal to effectuate such tuning.

Abstract: A remote commander transmits a command signal from a light emitting element controlled by a transmitting integrated circuit to an apparatus to be controlled. A single low voltage battery drives the remote commander, and a booster circuit boosts the low voltage supplied by the battery. The light emitting element and the transmitting integrated circuit are driven by the output voltage from the booster circuit.

Abstract: In known modulation current regulators, a low-frequency pilot signal is often superimposed on the digital useful signal and the two superposition products resulting in a light signal are evaluated. Due to the cut-in delay of a laser diode, the preconduction current of the laser diode in laser diode transmitters having transmission rates of at least a few 100 Mbit/s must be set so high that a superposition product only results in the light output signal and, therefore, a regulation of the modulation current is no longer possible in the known manner. For regulating the modulation current given high transmission rates, at least one pulse sequence is periodically inserted into the digital transmission signal or a pulse sequence already contained in the digital transmission signal is evaluated, the pulse sequence being composed of at least one part having a majority of logical one pulses and a part having a majority of logical zero pulses.

Abstract: An optical communication system includes a stationary master unit which is adapted to receive through a wired communication bus a plurality of separate communication input signals and communicate a corresponding plurality of separate communication output signals. The master unit converts the input signals to pulsed signals and optically transmits the pulsed signals corresponding to each of the separate signals during designated time slots to one of a plurality of separate communication units which preferably are portable units. The portable units reconvert the received pulsed signals to signals corresponding to the original communication signals. Each of the portable units also receives individually separate communication signals, converts the received communication signals to pulsed signals and optically transmits the pulsed signals to the master unit in the same manner.

Abstract: The connection system includes at least one connection assembly having at least one connection module with a connection capacity of N optical lines. A connection module comprises first, second, and third optical switch assemblies (C11 to C1n, C21 to C2n, and C31, C32). The first assembly is connected to the N optical lines, the second assembly is connected firstly to the first assembly and secondly to the junctors and the spare junctors associated with the N optical lines, and the third assembly is connected firstly to the first assembly and secondly to at least one test circuit via a line test optical fiber and via a junctor test optical fiber. When using narrowband optical switches, there are two switching assemblies, one for transmission and the other for reception of the signals conveyed by the optical lines, when using wideband optical switches, then a single switching assembly is used both for transmission and for reception, i.e. for both call directions.

Abstract: A medical diagnostics installation has an examination station at which a patient and medical examination equipment are disposed, and a control console disposed remotely therefrom. At least two different wireless control signal transmission channels are provided, each sending control signals to the examination station simultaneously by means of different types of information-carrying signals, such as an ultrasound signal and an infrared signal. Since the different types of information-carrying signals are affected by respectively different types of disturbances in the transmission path, the risk of an incoming control signal being misinterpreted due to the presence of a degraded signal is minimized.

Abstract: A reduced-blocking system where a perfect shuffle equivalent network having a plurality of node stages successively interconnected by link stages, is advantageously combined with expansion before the node stages and/or concentration after the node stages in a manner allowing the design of a system with arbitrarily low or zero blocking probability. An illustrative photonic system implementation uses free-space optical apparatus to effect a low loss, crossover interconnection of two-dimensional arrays of switching nodes comprising, for example, symmetric self electro-optic effect devices (S-SEEDs). Several low loss beam conbination techniques are used to direct multiple arrays of beams to an S-SEED array, and to redirect a reflected output beam array to a subsequent node stage.

Abstract: A device for providing an optical feedback path for a receiver comprises a header including a base having a major surface and first, second and third leads. The first and second leads extend through the base to form first and second posts on the major surface of the base and the third lead is electrically connected to the base. The portion of the first and second leads extending through the base are surrounded by electrical insulation so that the first and second leads are electrically insulated from the base. A submount comprising a flat insulating block with a layer of gold on its top and bottom surfaces is solder-bonded to the major surface of the base and the gold layer on the top surface of the submount is wire-bonded to the base. An LED is solder-bonded to the top surface of the submount and wire-bonded to the first post on the major surface of the base, the LED emitting optical radiation when it is forward biased.

Abstract: A fiber optic local area network including a plurality of passive star couplers each capable of connecting to a plurality of users. One connection input to and output from each passive star coupler is connected to a respective output and input of an active star coupler. The active star coupler stores the round-trip transmission times to each passive star coupler and upon receipt of a signal from a passive star coupler inhibits output to that passive star coupler for the signal duration and inhibits input from all other passive star couplers for the signal duration plus the round-trip transmission delay.

Abstract: An optical communication system is disclosed including an all-optical device whose output modulated optical beam is locked to an input modulated optical beam. In a specific embodiment of the system, the device may be a self-electro-optic effect device (SEED), which is operated as an oscillator by means of an associated tank circuit. Such an embodiment permits recovery of a clock frequency from a bit stream which is input into the device. When the output of the device is directed into an optical decision element, an all-optical regenerator may be realized.

Abstract: A non-autonomous fiber optic network having the capability of monitoring optical data communications of said fiber optic network comprises an optical fiber cable which provides an optical medium (i.e., bus) for communicating optical signals. A bus controller controls the communications of optical information on the optical fiber cable. The bus controller also monitors the optical information outputted on the optical fiber cable, thereby verifying the integrity of the optical information transmitted to terminals connected to the optical fiber cable. An optical interface of the bus controller taps a percentage of power that is outputted onto the optical fiber bus and routes that signal to a receiver unit of the bus controller. The signal coupled back to the receiver unit is utilized by the bus controller to monitor the integrity of the transmitted data that is outputted on the optical fiber bus.

Abstract: In an optical atmospheric link system for transmitting a light beam carrying an information signal between a transmitter and a receiver which is located apart from the transmitter, the transmitter includes a light source for generating the first light beam modulated with the information signal, a first optical system for transmitting the light beam toward the receiver, a second optical system for turning at least a portion of the light beam, and a third optical system for observing the light beam turned by the second optical system and the receiver.

Abstract: An optical atomic resonance filter using a pump laser, a buffer gas and calcium as an atomic vapor converts signals at the g Fraunhofer wavelength (422.674 nm) to UV light which is readily detectable by high sensitivity, large area, low noise, conventional photomultiplier tubes.

Abstract: In an optical transmission system including a trunk LAN having duplex optical transmission lines, and branch LANs connected with the trunk LAN through nodes, an optical signal on the optical transmission line of the trunk LAN is input to a node including an optical switch, an optical transmitting and receiving circuit, a serial-parallel converter, an internal bus, and a LAN interface. The optical signal input to the node is converted to an electric signal (serial date) by the optical transmitting and receiving circuit through the optical switch, and is converted to parallel data by the serial-parallel converter. Thereafter, the parallel data is output onto the internal bus. The LAN interface peforms an operation for outputting the parallel data onto the internal bus to the branch LANs. Data on the branch LAN is output to the optical transmission line by the operation opposite to that described above. The node can include a signal optical transmitting and receiving circuit.

Abstract: A low distortion optic fiber network having a feedback system which injects pilot tones into a base band input signal directly modulating an LED, optically detects the output resulting from the pilot tones, digitally samples the detected signal, and generates correction coefficients. The correction coefficients and the base band input signal are input to a correction circuit that pre-distorts the input signal in a non-linear manner and uses the distorted signal to modulate the LED. Pre-distorting the LED input signal compensates for the non-linearities of diode transfer characteristics and intermodulation between signals in the network thereby reducing harmonic and intermodulation distortion.

Abstract: A high-speed two-way optical data link has both light-emitting and light-sensing units mounted adjacent one another in a single housing together with a timing and control unit providing all signals necessary for simultaneous transmissions and reception of data. Synchronization to a clock signal is achieved by use of edge detectors which reset to zero counters in the timing and control unit whenever a transition in data pulses is sensed. A pair of computers are linked using a program called "Crosstalk" which performs full parity checking of all data received by an associated computer. Both computers are live handshaking and asynchronous at all times.

Abstract: An optical communication system is described wherein a message pathway is indicated by a destination address, manifested by an address time interval between a reference optical signal and an address optical signal. The optical communication system includes an optical switch for directing messages onto selected pathways. The switch includes a gate summer, and a reference circuit for applying a destination address portion of a message to the gate summer. A first delay circuit also applies the address portion of the message to the gating summer, while retarding it by a first address time interval. The gate summer sums the address portion from the reference circuit and the retarded address portion to produce a gating signal when the reference optical signal and address optical signal are time coincident. Switch means are further provided which are responsive to the gating signal to direct the message along a first selected pathway.

Abstract: An infrared detector device comprising a light projector adapted to output double-modulated infrared pulse light by modulating the amplitude of high frequency modulated light by means of low frequency waves, and a light receiver adapted to receive the double-modulated infrared pulse light. The light projector (1) comprises a 1/N-frequency dividing circuit (12) for dividing by N the frequency of the basic frequency signal from a basic frequency oscillator in such a manner that it can be set for switching, a second frequency dividing circuit (13) for dividing the frequency of the 1/N frequency-divided signal by a given factor to produce a low frequency signal, a frequency combining circuit (14) for combining the 1/N frequency-divided signal and the signal frequency-divided by a given factor, and a switch (17) for switching the frequency dividing factor for the 1/N-frequency dividing circuit (12).