Abstract: An optical end terminal in which protection switching is implemented by using (i) the optical data receiver thereof for detecting a path failure and (ii) the optical data transmitter thereof for signaling the detected path failure to the protection-switching circuit. In an example embodiment, the optical data receiver is configured to detect a path failure based on the presence of certain data-recovery errors. The optical data transmitter is operatively connected to the optical data receiver and configured to generate an in-band dither tone of a predetermined frequency in response to such failure detection. The protection-switching circuit is configured to (i) detect dither tones in the optical signals passing therethrough and (ii) connect the optical data receiver to the protection path instead of the working path in response to detecting the dither tone of the predetermined frequency.

Abstract: Aspects of the disclosure are directed to auto-sweeping impedance-matching circuitry that matches an impedance of an RF antenna. As may be implemented in accordance with one or more embodiments, a transmitter that is configured and arranged to transmit signals to remote devices via the RF antenna, is used to communicate a plurality of test signals to the impedance-matching circuitry, with each test signal having a designated frequency and/or test signal pattern that is different than the designated frequency and/or test signal pattern of the other test signals. A characteristic of each of the test signals as passed through the impedance-matching circuitry is detected. For each of the test signals generated for the auto-sweep, the detected characteristic is compared to an expected characteristic for the test signal, and an output indicative of compliance of the impedance-matching circuitry with a design specification is generated and transmitted in response to the comparison.

Abstract: In an optical communication abnormality-recovery system and method, when an abnormality occurs in transmission and reception of one wavelength of an optical line terminal of a PON system, an optical network unit that is performing communication at a certain wavelength switches the wavelength for performing the communication to another backup wavelength that is instructed in advance. The optical line terminal also performs switching so that the communication is performed using the same backup wavelength as in the optical network unit.

Abstract: A receive apparatus in a strong magnetic alternating field is disposed in a magnetic resonance tomography (MRT) system. The MRT system includes at least one receive apparatus for a magnetic resonance high frequency (MR-HF) signal. The receive apparatus includes a receive coil element for receiving the MR-HF signal, an optical modulator, in which an electrical control input is coupled to the receive coil element, and an optical output for outputting an output signal of the modulator. The optical modulator forms an optical demodulation device for the MR-HF signal. The optical modulator is coupled to a laser light source via an optical input that is configured to generate a laser light. A light intensity of the laser light varies periodically with a predetermined frequency.

Abstract: Systems and methods for distributing signals in an optical network are disclosed. In accordance with one embodiment of the present disclosure a method for distributing signals in an optical network comprises combining input signals into one or more output signals, determining, an availability status of optical lanes for carrying the output signals and distributing the output signals to optical transmitters associated with the optical lanes if the availability status indicates that the optical lanes are available.

Abstract: An optical data link includes first and second pluralities of transmission devices, at least one of which is configured as an array. A multichannel transmission link has a first end connected to the first plurality of transmission devices and a second end connected to the second plurality of transmission devices so as to form a plurality of parallel transmission channels therebetween. The multichannel transmission link includes a multicore fiber with a plurality of individual cores having a configuration matching the array configuration of the at least one plurality of transmission devices. The multicore fiber has an endface connected directly to the at least one plurality of transmission devices, with the individual cores of the multicore fiber aligned with respective devices in the at least one plurality of transmission devices. Further described are access networks and core networks incorporating a transmission link comprising at least one span of a multicore fiber.

Abstract: An optical system comprising a frequency modulated laser source adapted to produce a frequency modulated optical beam, an optical spectrum reshaper (OSR) adapted to receive the frequency modulated optical beam from the laser source and convert it into an amplitude modulated optical beam, a focusing lens adapted to receive the amplitude modulated optical beam from the OSR and focus the same, and an optical fiber adapted to receive the amplitude modulated optical beam from the focusing lens and transmit an optical signal; characterized in that the OSR has a central axis, the focusing lens has a central axis, and the optical fiber has a central axis, with the central axis of the optical fiber being laterally offset from at least one of the central axis of the OSR and the central axis of the focusing lens so as to effect spatial filtering and thereby generate the desired optical transmission characteristics for the resulting optical signal in the optical fiber.

Abstract: An optical network system is provided which has a signal protection function and is able to be constructed of communication nodes manufactured at low costs. An optical signal transceiver has at least one optical signal transmitting device and at least one optical signal receiving device to transmit and receive an optical signal between nodes facing each other. A switching device, when no failure has occurred in the optical signal transmitting communication line and optical signal receiving communication line, transmits an optical signal from the optical signal transmitting device to an optical signal transmitting communication line and an optical signal having been received from the optical signal receiving communication line to an optical signal receiving device.

Abstract: An optical transmission apparatus includes redundant line cards each having a plurality of ports, a hardware unit and a CPU. The hardware unit obtains failure information on redundant lines for each port. The CPU determines switching control of the redundant lines based on the failure information. Then, the hardware unit switches the redundant lines based on the switching control determined by the CPU, so as to transmit an SDH/SONET optical signal in a ring network. The CPU of one of the line cards is set as a master CPU on the corresponding line card to control switching of the redundant lines. Further, the CPU of the other line card is set as a slave CPU.

Abstract: A transmission apparatus that receives an optical signal by selecting any one of a plurality of provided optical signal transmission paths through protection control is configured to include a plurality of optical signal outputting sections that output the optical signals transmitted through said optical signal transmission paths respectively as optical signals having wavelengths that are different from each other, a wavelength selective optical switch capable of selectively outputting light of a wavelength corresponding to any one of the optical signals coming from the optical signal outputting sections on the basis of the frequency of a controlling frequency signal, and an optical switch controlling section that supplies said controlling frequency signal to the wavelength selective optical switch so as to output the optical signal coming from the optical signal transmission path side that is selected by said protection control among the optical signals coming from the optical signal outputting sections.

Abstract: A core network shared by a large number of edge nodes comprises core nodes interconnected by core channels. Selected core channels are provided with buffers to enable temporal alignment of signals arriving at any core node from several other core nodes. A buffer may be provided at either end of a core channel. Otherwise, all other ports of the core node may be bufferless. Providing such buffers enables the construction of high-capacity wide-coverage network comprising a large number of core nodes shared by numerous edge nodes. Methods of temporal coordination among the network nodes are disclosed.

Abstract: A configuration for detecting optical signals of at least one optical channel of a planar optical circuit. At least one deflection device is provided, which couples the optical signals of at least one optical channel at least partly out of the plane of the circuit, and one detection unit is provided, which detects the signals that are coupled out outside the plane of the circuit. Therefore, a simple metrological monitoring of the signals of the optical channels of a planar optical circuit occurs with only slight signal losses and without undesirable crosstalk.

Abstract: An optical network has an optical splitter connected to (1) a working optical subscriber unit (OSU) of a working circuit via a working optical fiber, (2) a protection OSU of a protection circuit via a protection optical fiber, and (3) one or more optical network terminals (ONTs). The present invention enables fast protection switching from the working OSU to the protection OSU. In one embodiment, the arrival times of corresponding upstream ranging reply PLOAM cells are measured at both the working and protection OSUs during ranging operations of the working OSU. In another embodiment, a cell delineation procedure is initiated at the protection OSU during normal, non-ranging operations of the working OSU to enable the protection OSU to correctly delineate upstream cells and the arrival times of corresponding upstream cells are then measured at both the working and protection OSUs.

Abstract: In an optical switching apparatus having redundantly-arranged optical switches, a route switching operation mode, an autonomic redundant switching operation mode and a compulsory redundant switching operation mode are discriminated from one another so that these operation modes are prevented from being executed at the same time, and also proper mask processing is performed at every switching operation mode. Therefore, emission of an undesired alarm and thus occurrence of malfunction when each switching operation is carried out can be prevented.

Abstract: A wiring pattern of a circuit board comprises two reference voltage lines holding a signal line therebetween, whereas the reference voltage lines on both ends are electrically connected to a conductive bracket. The bracket covers and electrically shields lead pins connecting a light-receiving device unit or light-emitting device unit to the circuit board.