Abstract: The present invention provides improved compatibility between optical transmitters of various data rates and WDM optical communication systems. In the present invention, optical remodulators are configured to receive an optical signal, separate the information from that optical signal into N information streams (where N is a whole number greater than or equal to 2), and place the information onto N optical channels within the channel plan of a WDM optical system. Alternatively, the present invention provides optical remodulators configured to receive N optical signals, combine the information from the N optical signals, and place the information onto a single output optical channel having a wavelength within the channel plan of a WDM optical system.

Abstract: The self-oscillation frequencies of injection-locked laser devices 5-1 through 5-M are preset to the frequency of the signal light to be transmitted by the optical add-drop device, and the self-oscillation frequencies of the injection-locked laser devices 6-1 through 6-N are preset to the frequency of the signal light to be branched by this device. Wavelength-division multiplexed signal light inputted from an input optical line 1 is split in an optical splitter 2 and inputted to the injection-locked laser devices. Signal light whose wavelength has been set for the injection-locked laser devices 5-1 through 5-M is amplified by these injection-locked laser devices 5-1 through 5-M and inputted to an optical combiner 10. Signal light whose wavelength has been set for the injection-locked laser devices 6-1 through 6-N is outputted to branching optical lines 8-1 through 8-N.

Abstract: An information processing system has a plurality of nodes each including one or more CPUs that utilize monitoring of a common bus, wherein the plurality of nodes are connected to one another by a connection path that cannot monitor information on an internal bus in each node. Information required to perform synchronized operation in a node or among nodes is transmitted to an arbiter via an optical fiber serving as a transmission path different from the connection path, and part of this information is again distributed from the arbiter to each of the nodes based upon the information. The system operates in such a manner that the information is reflected in its own node based upon the re-distributed information. Further, in order to perform the synchronized operation among CPUs based upon the re-distributed information, the system controls the information to be distributed from each node to arbiter.

Abstract: An optical transmission link has both a transmitter module and a receiver module operable under uncooled conditions, i.e., without the need of costly cooling equipment, such as thermoelectric coolers. The optical transmission system includes both a semiconductor laser diode source and an optical receiver module that are both designed to operate uncooled under high frequencies (e.g., GHz range) over a wide temperature range without significant changes in signal bandwidth and at temperatures in excess of 125.degree. C. Compensation is provided to reduce the effect of photodiode noise and amplifier noise. In addition, temperature compensation can be provided that provides for overall reduction in receiver noise across the bandwidth of the receiver module through maintenance of a temperature environment optimizing receiver performance.

Abstract: A discontinuous ring is formed by separate bidirectional optical communication links, with possibly different transmission speeds, synchronous or asynchronous transmission, and ratios of working to protection channels, each linking a pair of terminals in different nodes of a communication system. To protect protection-switched traffic on a communication link from a link failure, it is routed around the ring via the protection channel of the other communication links. To this end, an optical switch is provided between the protection channel of each link and the associated terminals in each node, and is controlled differently in nodes adjacent the link failure and in nodes not adjacent the link failure to route the protection-switched traffic accordingly. Rapid protection switching is facilitated by controlling the optical switches using wavelength detectors directionally coupled to the protection channel at each node.

Abstract: Optical loop-back is provided within an optical restoration system of an optical communication network. According to one embodiment, an optical restoration system includes first and second spare optical links (also called restoration paths) optically coupled in parallel between first and second optical cross-connect switches. Each restoration path includes a light regenerator and an optical amplifier. First and second optical cross-connect switches are each switched to provide respective optical loop-back paths between the first and second restoration paths or spare links. In one example, the optical loop-back paths can be configured within the optical cross-connect switches. In another example, the optical cross-connect switches are configured to couple optical signals between an external loop-back coupler and the first and second restoration paths or spare links.

Abstract: An optical fiber amp repeater, provided on an optical transmission channel in an optical system, having an excitation light output section for supplying an excitation light for amplifying a received optical signal, and a main signal light amplifier section for supplying the optical signal which is amplified while going through the rare earth dope fiber after combining the received optical signal with the excitation light supplied from the excitation light output section, the excitation light output section including an excitation light source for transmitting the excitation light and an excitation light source driving circuit for driving the excitation light source, the excitation light source driving circuit controlling the excitation light source according to a given data and modulating the excitation light by high frequency wave, thereby to create an auxiliary signal containing the given data.

Abstract: The present invention is directed towards an optical ADM apparatus provided with a narrow band-pass filter which is capable of minimizing declination of the transmission characteristics. An optical transmission prohibiting element composed of an optical isolator and a fiber grating is connected in series to the downstream of a fiber grating interposed between two optical circulators. The drop light is reflected by the fiber grating and released from an output optical fiber of the optical circulator. A leak component of the drop light having passed through the fiber grating appears on the side of the isolator and runs across the isolator to the other fiber grating. Most of the leak component is however reflected by the fiber grating while its small portion enters the optical circulator via the fiber grating. The small portion of the leak component is as small as negligible and will hardly interfere with the add light. The optical transmission prohibiting element may be an optical circulator.

Abstract: A laser communication system adapted for use in a satellite communication system. The satellite carries a laser communication system. The laser communication system includes a plurality of active and passive optical elements packaged in a monolithic, or single block, structure for interfacing between a focusing beam director of the satellite and laser transmitters/receivers of the laser communication system. Laser energy is directed between the beam director and the transmitters/receivers by the active and active optical elements, such laser energy passing through the monolithic structure solely as collimated light. In this way, relay elements, such as diffractive optics and focusing lenses, and there concomitant alignment requirements, are eliminated from the monolithic structure.

Abstract: A wavelength division multiplexing optical transmission apparatus comprises an optical wavelength demultiplexer which demultiplexes, for each wavelength, the wavelength division multiplex optical signal transmitted via an optical fiber, receivers which receive the output beams from the optical wavelength demultiplexer, a wavelength detector that detects the difference between the wavelength of a transmitter and a wavelength minimizing the loss in the optical wavelength demultiplexer, and an alarm generator that determines an abnormality when the wavelength difference has exceeded an allowable value and raises the alarm.

Abstract: A method and apparatus for optical signal routing in an optical network that includes one or more optical fibers to carry multiplexed signals. Each optical fiber may include a plurality of optical carriers with each optical carrier operating at a different wavelength. The optical network includes an optical network routing apparatus to receive the multiplexed signals from the optical fiber, to categorize the multiplexed signals as local signals or as non-local signals, to drop the local signals to a local switch, and to transmit the non-local signals to the optical fiber for further routing in the optical network. Advantageously, the transport of multiplexed signals on optical carriers of different wavelengths on a single optical fiber multiples by the number of optical carriers the bandwidth capacity of the optical fiber.

Abstract: Apparatus and method for interfacing a wired communications network (12) to a wireless communications network (13). Both networks operate with a CSMA protocol. An interface unit (16) includes circuitry (28) for bidirectionally interfacing to the wired medium for transmitting messages thereto and for receiving messages therefrom. The interface unit also includes circuitry (29, 22, 24, 26) for bidirectionally interfacing to the wireless medium for transmitting messages thereto and for receiving messages therefrom. The interface unit further includes logic (28) for bidirectionally routing messages received from the wired medium to the wireless medium and for routing messages received from the wireless medium to the wired medium. A further feature of the interface unit is a collision detector (30), responsive to the reception of a rebroadcast wireless transmission, for comparing the transmitted message to the received rebroadcast message to determine if a collision has occurred.

Abstract: A data communications coupler is provided for communicating data related to various operating conditions of a tractor and/or a trailer. The data communications coupler preferably includes a first coupler portion arranged to connect to a tractor. The first coupler portion has a first lens positioned therein for allowing data communications signals to pass therethrough. A second coupler portion is arranged to connect to a trailer and to connect to the first coupler portion. The second coupler portion has a second lens positioned therein for allowing data communication signals to pass therethrough. A data communicator is positioned in the first and second coupler portions for communicating data between the first and second coupler portions through the first and second lenses. Each of the first and second lenses preferably has a body integrally formed of a translucent material for allowing light to pass therethrough.

Abstract: An optical-signal transmitting apparatus performs predetermined digital modulation on a digital signal to be transmitted. The modulated digital signal is then converted into a light signal which is output. The output light signal is scattered and radiated to external space. The wavelength of the radiated light is preferably between 1.4 and 1.6 microns. Modulation is preferably performed based on a duration of a symbol to obtain not less than a predetermined ratio, e.g., 3, of a carrier wave to an interference wave. The scattered light signal is received and is preferably converged by a hemispherical lens mounted to a light receiving device. The received light signal is converted to an electrical signal and digital demodulation is performed.

Abstract: An optical time-division multiplexer in which the phase difference between two optical signals to be used for the synthesis of an output optical signal thereof is maintained at a constant value, regardless of variations in accuracy of the manufacture thereof. Thereby, stable output optical signals are obtained at all times. The optical time-division multiplexer includes first and second optical modulators to respectively output first and second optical modulation signals synchronized with a clock signal and corresponding to different time slots, respectively; an optical coupler for performing time-division multiplexing of the first and second optical modulation signals respectively outputted by the first and second optical modulators; and an optical-phase adjusting unit to receive at least one of the first and second optical modulation signals and to regulate an optical phase of the inputted optical signal.

Abstract: A remote control apparatus for use with an equipment which includes a master apparatus and a slave apparatus remotely located from the master apparatus. The master apparatus transmits a control signal to the slave apparatus so as to remotely control the slave apparatus. The master apparatus has a light-transmitting section therein which projects outwardly of the master apparatus. The light-transmitting section transmits a light signal representing a control signal generated in the master apparatus. The slave apparatus has a light-receiving section therein which receives the light signal. The light-transmitting section may be detachably mounted to the master apparatus. The light-transmitting section may be adapted to rotate relative to the master apparatus after the light-transmitting section has been mounted to the master apparatus. The light-transmitting section may include a plurality of light-emitting elements so that light is emitted over a wide area.

Abstract: An audio video apparatus controller connected to a timer provided in a desired audio video apparatus wherein a reserve number indicative of the order of input data and a time are uniquely and correspondingly stored each time the time is input. The audio video apparatus controller is comprised of time input devices for inputting the time to the timer, selecting devices for selecting one of the audio video apparatus, setting devices for setting operation conditions of the selected audio video apparatus in association with the time, and a control circuit responsive to a command signal from the timer to control the selected audio video apparatus so that the selected audio video apparatus is operated at the input time in accordance with the operation conditions. Therefore, the timer can be utilized in the extended range and a plurality of audio video apparatus can be controlled in a well-coordinated fashion.

Abstract: A switchable wavelength router has a first polarization-dependent routing element (e.g., a birefringent element, polarized beamsplitter, or angled polarization separator) that decomposes and spatially separates an incoming WDM optical signal into two orthogonally-polarized beams. A first polarization rotator selectably rotates the polarization of one of the beams to match the polarization of other beam, based on an external control signal. A wavelength filter (e.g., stacked waveplates) provides a polarization-dependent optical transmission function such that the first beam decomposes into third and fourth orthogonal beams, and the second beam decomposes into fifth and sixth orthogonal beams. The third and fifth beams carry a first spectral band at a first polarization and the fourth and sixth beams carry a second spectral band at an orthogonal polarization. A second polarization-dependent routing element spatially separates these four beams into four horizontally polarized and vertically polarized components.

Abstract: Detailed mapping of the magnetosphere is made possible by deploying hundreds of attitude-impervious microsatellites, in the form of small corner reflectors with piezoelectric mirror surfaces, from a single mother satellite at spacings of as little as 1 km in equatorial and elliptical orbits. The microsatellites carry magnetosensors whose output is transmitted to a ground station by modulating the reflection of a laser beam transmitted to the microsatellite by the ground station. Various refinements of the laser data link are also disclosed.

Abstract: A DPSK communication system employs an optical signal which comprises plural, coherent, optical frequencies, each optical frequency positioned within a range of frequencies (i.e., a "frequency slot"). The optical signal comprises plural frequency slots, with the wavefront in each time segment of each frequency slot being phase modulated in accordance with data signals. Plural frequency slots are transmitted "in parallel", in each of a plurality of succeeding time segments. A demodulator includes first and second optical paths, the first component of the optical signal directed onto the first optical path and a second component directed onto the second optical path. A modulator is positioned in at least one of the optical paths and is responsive, during a time segment, to a first applied control signal, to alter the phase, and thus the frequency, of the first component by approximately one frequency slot.