Abstract: A communications terminal includes a first aperture configured to receive laser signals from ground laser sources, pick-off mirrors configured to receive laser signals from mobile laser sources, an optical assembly configured to receive the laser communications signals from ground laser sources and mobile laser sources, wherein the optical assembly is configured to focus laser signals onto a common focal plane, and laser receivers located at the focal plane configured to receive laser signals from at least one laser source at a time.

Abstract: The disclosure is directed toward an optical transmission system comprising a primary path disposed between a first end and a second end. The primary path is configured to transmit optical signals between the first end and the second end. A secondary path is disposed between the first end and the second end. The secondary path is configured to transmit optical signals between the first end and the second end, e.g., in the event of a break in the primary path. A first variable ratio coupler is coupled to the primary path and the secondary path between the first end and the second end. The first variable ratio coupler is configured to adjust a coupling ratio between the primary path and the secondary path.

Abstract: Disclosed is a broadcast/communication unified passive optical network system.

Abstract: A polarization mode dispersion (PMD) controller device for controlling the state of polarization of an optical light wave comprising a dispersion compensation unit (2; 25; 40) and an adaptation control unit (6; 28; 44), wherein the dispersion compensation unit (2; 25; 40) comprises a multitude of compensation stages processing the optical light wave, and wherein the adaptation control unit (6; 28; 44) controls the dispersion compensation unit (2; 25; 40) is characterized in that at least one feed-forward signal tap (4; 26a-26c, 73a-73c) is provided tapping the optical light wave inserted into one of the compensation stages, that the feed-forward signal(s) is(are) fed into a distortion analyzer unit (5; 27; 66) and that the distortion analyzer unit (5; 27; 66) provides the adaptation control unit (6; 28; 44) with information about the incoming optical light wave. It accelerates the adaptation speed and lowers the costs of a high-speed PMD controller device.

Abstract: A communication optical system having a compact structure and capable of preventing crosstalk is disclosed. The communication optical system includes a light source, a light-receiving element and a beam-splitting member. The beam-splitting member performs one of transmission and reflection towards an incident/emergent port, and performs one of reflection and transmission towards the light-receiving element of a second light beam from the incident/emergent port. The light source and the light-receiving element are arranged on the same side with respect to the beam-splitting member.

Abstract: An optical add/drop multiplexer (OADM) adapted to route optical signals having at least two different bit rates. The OADM has at least two sets of DWDM channels, e.g., with channels in a first set having a first bandwidth value suitable for the transmission of 10-Gb/s signals and channels in a second set having a second bandwidth value suitable for the transmission of 40-Gb/s signals. The first and second sets occupy two different spectral bands and the first set has two subsets of interleaved channels. In one embodiment, the OADM has first and second optical branches adapted to process optical signals corresponding to first and second groups of channels, respectively. The first group includes a first subset from the first set while the second group includes the second set and a second subset from the first set. Advantageously, OADMs of the invention may be used to create independent processing paths for different groups of channels. As a result, a communication system having those OADMs can be upgraded, e.g.

Abstract: An optical communication method and apparatus are provided, the apparatus including polarization controllers, and drive circuitry for driving the polarization controllers at a plurality of frequencies such that the penalties from PMD, PDL and PDG are mitigated.

Abstract: In this application, the invention is a novel heuristic mechanism of working path and backup path reservation for highly utilizable WDM mesh networks, which we call dynamic-network adapted cost selection (DAC-selection) mechanism. One of its characteristics is simple traffic distribution mechanism, and the performance of DAC-selection mechanism is superior to that of Random selection (R-selection) and Advanced Combined Min-cost selection (ACM-selection) mechanism. DAC-selection mechanism provides simple cost function by assigning proper weights to each component of the cost function and the total cost is obtained by just summing up the individual cost. Therefore, it is possible to select a best pair of working path and backup path which consumes least wavelength for reservation.

Abstract: The present invention overcomes problems associated with switch isolation, noise and crosstalk suppression, insertion loss, spurious reflections, wavelength tolerance, and compactness that are present in varying degrees in other add/drop systems. The present invention includes devices or components that include, but are not limited to high efficiency switchable gratings.

Abstract: A 90 degree Alternate-Phase (AP) on-off keying (OOK) transmission format for high bit rate, long-haul optical transmission systems employing a chirped or a chirp-free pulse stream generated by a pulse generator (e.g., Mach Zehnder modulator) driven by mixing two electrical signals—one for intensity modulation and another for pulse modulation. These electrical signals may be two properly skewed sinusoidal electrical signals at half the desired data rate thereby generating a pulse stream in which the maximum optical phase modulation occurs at the intensity peak of each pulse and is 90 degrees out of phase with its nearest neighbors.

Abstract: Minimum shift keying (MSK) is used as the coding scheme in a high bit rate optical transmission system, and the signal format is either RZ (return-to-zero) or NRZ (non-return-to-zero). The system can combine multiple individual channels with different wavelengths in a WDM or dense wavelength division multiplexed (DWDM) arrangement. Dispersion management can be provided using several techniques, such as quasi-linear transmissions or conventional RZ transmissions. At the transmitter, an optical MSK transmitter is used to modulate the phase of a stream of high bit rate (e.g., 40 Gbit/s) optical signals. Many such data streams can be combined in a wavelength division multiplexer and transmitted to a remote receiver, where the signal is wavelength division demultiplexed. The encoded data in each wavelength channel is then recovered by an MSK receiver, which may consist of a delay demodulator and a balanced detector.

Abstract: A signal communication apparatus of a clock reproduction system in which clock signals are extracted from each of parallel data signals for redigitizing each of the data signals. The apparatus includes a reference clock signal generating circuit which is comprised of a clock extraction circuit for extracting a clock signal from each of a plurality of bits of received data signals, and a clock signal selection circuit for selecting one of the extracted clock signals. Alternatively, the reference clock signal generating circuit may be comprised of a data signal selection circuit for selecting one of a plurality of received data signals, and a clock extraction circuit for extracting a clock signal from the selected bit. Based on the resultant reference clock signal, clock signals are obtained that are phase-adjusted for redigitizing each bit of the received data signals.

Abstract: A system according to embodiments of the invention may include a first communication path that converts an optically-modulated source signal to a radio signal based on a detected degradation in a quality of a received optical signal, and a second communication path that converts a radio-modulated source signal to an optical signal based on a detected degradation in a quality of a received radio signal. The system has the ability to automatically adapt to diverse weather conditions to improve the reliability of a communication link without user intervention while supporting multiple modulation schemes.

Abstract: Dispersion compensation values are set so as to be transmittable to any path groups in a WDM optical communication system having OADM nodes, which includes transmitting-end and receiving-end terminal nodes; a WDM optical communication transmission line including a plurality of spans each having an optical fiber, the plurality of spans joining the transmitting-end and receiving-end terminal nodes; and a plurality of add drop multiplexing (OADM) nodes disposed on the optical communication transmission line; wherein when taking as the reference a residual dispersion target value of between the transmitting-end terminal and receiving-end terminal nodes, a residual dispersion target value for a node segment between one of the terminal nodes and one of the add drop multiplexing (OADM) nodes and a residual dispersion target value for a node-to-node segment between two of the add drop multiplexing (OADM) nodes are set so as to be proportional to ratios of the span counts in the node segment and in the node-to-node se

Abstract: An apparatus and method for processing a supervisory signal for optical network applications. The apparatus includes a subcarrier transmission system configured to receive a first supervisory signal and output a second supervisory signal, and an electrical-to-optical conversion system configured to receive the second supervisory signal and a first data signal and output a first optical signal. Additionally, the apparatus includes an optical-to-electrical conversion system configured to receive the first optical signal and output a first electrical signal and a second data signal, and a subcarrier reception system configured to receive the first electrical signal and output a third supervisory signal. The second supervisory signal is associated with a first subcarrier frequency. The first data signal is associated with a first data bandwidth, and the first data bandwidth includes a first data frequency. A ratio of the first subcarrier frequency to the first data frequency ranges from 0.8 to 1.

Abstract: A single, normally inactive, protection ring, provides protection against a working channel failure in a fiber optic ring network. The protection channel is established and put into operation by a series of steps that are triggered by the detection of signal degradation or loss of light from one transponder by the other transponder. Each node reacts to a failure of another node in substantially the same way. Incoming traffic from external sources is rerouted from a working input-output interface to a protection interface, to establish a path for the protection signal. Signals are sent between nodes enabling the two nodes to resume communication. Only the portion of the protection ring between nodes is placed into service.

Abstract: An architecture and method for performing coarse-grain reservation of lightpaths within wavelength-division-multiplexed (WDM) based photonic burst switched (PBS) networks with variable time slot provisioning. The method employs a generalized multi-protocol label switched (GMPLS)-based PBS label that includes information identifying each lightpath segment in a selected lightpath route. A resource reservation request is passed between nodes during a forward traversal of the route, wherein each node is queried to determine whether it has transmission resources (i.e., a route lightpath segment) available during a future timeframe. Soft reservations are made for each lightpath segment that is available using information contained in a corresponding label. If all lightpath segments for a selected route are available, the soft reservations turn into hard reservations. The stored reservations enable quick routing of control burst that are employed for routing data during scheduled use of the lightpaths.

Abstract: A bi-directional (BiDi) electrical to optical converter (transceiver) module is described that contains means for communicating in a full duplex fashion over one fiber. Furthermore, an automatic fail-over capability is included which allows redundancy to be build in to the transceiver. In one configuration, a BiDi transceiver module contains two lasers at different wavelengths and a means for establishing which wavelength to communicate with. An example of an application for the described invention is a storage area network application which requires redundant links and are currently bound by the number of fibers connecting to the front panels of switches.

Abstract: Embodiments of the present invention provide a system and method for routing optical data. In one embodiment of the present invention, data can routed in a non-blocking fashion from a plurality of the ingress edge units to a plurality of egress edge units by selectively connecting the ingress edge units to the egress edge units at a photonic core. Switching at the photonic core can be driven by a clock signal and does not require an electrical to optical conversion to occur at the core. This can allow switching on the nanosecond level, substantially faster than many prior art systems.

Abstract: A router comprising an interface module (IM), having an optical path and an electrical path and a speed sensor coupled between an input of the router and an input of the IM. The speed sensor is adapted to receive a packet and detect a speed of the IM connection and in response to the speed of the IM connection being above a threshold value, the speed sensor provides the packet to the optical path of the IM and in response to the relative speed being below the threshold value, the speed sensor provides the packet to the electrical path of the IM.