Abstract: The disclosed methods and apparatuses provide a unique and cost efficient approach to using traffic channels of an optical mesh network, and sometimes optical supervisory channels, for carrying timing information (e.g., BITS timing signals), thus eliminating the need to use external BITS sources at remote add/drop nodes of a network. Planning the distribution of timing in such an optical mesh network includes identifying in the network a source node associated with an external timing source, identifying optical light paths between nodes in the network, and, for nodes other than the source node, selecting optical light paths originating either directly or indirectly from the source node to use to derive timing information.

Abstract: An optical transceiver, optical network and methods for using the same are disclosed. The optical transceiver and/or optical network and related methods may be useful for independently monitoring the optical transceiver and/or optical network. The optical transceiver generally includes an optical receiver configured to receive optical information; circuitry configured to calculate signal strength values of the received optical information from a plurality of remote optical transmitters; logic configured to process the signal strength values for each of the plurality of remote optical transmitters; and one or more memories configured to store the signal strength values. Optionally, the optical transceiver may notify a system or host when the transceiver, network or component thereof is operating outside a predetermined threshold.

Abstract: An optical modulator includes: a modulator including an optical waveguide provided in a semiconductor substrate having an electro-optical effect and an electrode to apply an electric field depending on a bias voltage and a modulation signal to the optical waveguide; a driver circuit to generate a modulation signal in accordance with an input signal; a superimposer to superimpose a reference signal on the bias voltage, the reference signal having lower frequency than the modulation signal; and a controller to control a bias voltage in a direction orthogonal to a modulation direction of the modulator based on the frequency component of the reference signal extracted from a modulated optical signal generated by the modulator.

Abstract: An optical receiver including a photo detector for converting a light signal into an electrical current signal and a preamplifier circuit for receiving the electrical current signal and outputting a corresponding voltage signal. In one example, the preamplifier circuit includes a first transistor having: (i) a high impedance node connected to an input node connected to receive the electrical current signal from the photo detector, and (ii) a control terminal connected to receive active negative feedback proportional to the electrical current signal received at the input node.

Abstract: Novel tools and techniques that can be used to detect network impairment, including but not limited to impairment of optical fiber networks. In an aspect, such tools and techniques can be deployed at relatively low cost, allowing pervasive deployment throughout a network. In another aspect, such tools and techniques can take advantage of a “dying gasp,” in which a network element detects a sudden drop in received optical (or electrical) power, resolution, etc. at short time scales and sends a notification across the network before the connection is completely compromised. In yet another aspect, some tools can include a supervisory function to analyze aspects of the dying gasp with the goal to determine network segments associated with an impairment and an estimate of the location of an impairment within the network.

Abstract: A transmitter in a visible light communication system is provided, in which a plurality of light sources emit light in different colors, a data converter converts data to predetermined chromaticity coordinates, a data transmitter emits light having a chromaticity corresponding to the chromaticity coordinates by controlling light intensity of each of the light sources, and a pre-light emitter emits light having chromaticities corresponding to all chromaticity coordinates by controlling the light intensity of each of the light sources, before the light intensity control of the data transmitter.

Abstract: A passenger services system of an aircraft includes a cabin services system of a passenger service unit in the aircraft. The passenger service unit is associated with a passenger seat of the aircraft. The passenger services system further includes an infrared transmitting unit associated with the passenger seat. The infrared transmitting unit is configured to send signals to control operation of the cabin services system. The passenger services system includes a control unit including an infrared receiver. The control unit is associated with the passenger service unit. The infrared receiver is configured to receive the signals from the infrared transmitting unit. The control unit is configured to control the operation of the cabin services system in response to receiving the signals.

Abstract: An optical channel data unit (ODU) switch includes a set of two or more client cards, a set of two or more line cards, and a set of two or more switch cards. Each switch card is connected to all client cards, all line cards, and all other switch cards, and each client card, line card and switch card includes control logic for managing an operation of the ODU switch in a distributed manner.

Abstract: A joint-optimization method addresses the generalized routing and wavelength assignment problem with variable number of combined 1+1 dedicated and shared connections. The inventive method enables a solution in time that is polynomial of the input size. Thus, the time complexity of the joint-optimization method is significantly less than that of existing methods.

Abstract: In some embodiments, an apparatus includes a coherent optical receiver that can receive during a first time period a set of in-phase signals and a set of quadrature signals having a skew from the set of in-phase signals. The coherent receiver can blindly determine a delay between the set of in-phase signals and the set of quadrature signals based on the set of in-phase signals and the set of quadrature signals. The delay includes an intersymbol portion and an intrasymbol portion. The coherent optical receiver can apply the delay at a second time after the first time period such that a skew after the second time is less than the skew at the first time period.

Abstract: Described herein is an optical channel monitor (100), including a plurality of input ports in the form of optical fibers (102) disposed in a vertical “port displacement” dimension. Each fiber (102) inputs a respective optical beam (103) having a plurality of individual wavelength channels. A lens (104) collimates each beam and converges the beams in the port displacement dimension to a focal plane (105). The collimated and converged beams are incident onto a rotatable micro-electromechanical system (MEMS) mirror (106), which selectively directs each optical beam onto a wavelength dispersion element in the form of a grism (108) at a predetermined angle (denoted by ?) in a horizontal “dispersion” plane. The grism (108) spatially separates, in the dispersion plane, the wavelength channels contained within each optical beam (103) by diffraction. The angle at which each channel is diffracted is controlled by the angle ?.

Abstract: A system for implementing a radio over fiber (RoF) transmission in a passive optical network (PON), said passive optical network comprising a trunk line, a remote node, and a plurality of leaf nodes connected to said remote node, wherein one of said plurality of leaf nodes comprises a baseband processing unit for performing a baseband processing on a signal received via said trunk line to perform the transformation to radio over fiber by generating a radio over fiber signal and to forward the resulting radio over fiber signal to said remote node, wherein said remote node is adapted to forward the radio over fiber signal received from said leaf node to the other leaf nodes of said passive optical network.

Abstract: A method for providing access to a passive optical network for services to homes or businesses from two or more telecommunications service providers and a billing means is described. A first service provider connects to a point of presence at one side of passive optical network. The provider transmits the appropriate services through this network to an authorization receiver. The authorization receiver is used to receive a periodic authorization code from the network provider to enable the appropriate services from the service provider to be transmitted to a subscriber at a home or business. The authorization receiver enables an optical fiber path to be established for the services to flow to and from the home or business.

Abstract: An optical transmission device includes: a switching configured to be capable of switching a transmission path to which light is input from a first transmission path to a second transmission path; a first calculation unit configured to calculate, based on a difference between a first light level of the first transmission path and a second light level of the second transmission path, a first control amount for the second light level; and a control unit configured to perform a first control in which the second light level is decreased or increased based on the first control amount upon switching of the transmission path.

Abstract: A distributed antenna system includes a master unit configured to receive at least one set of multiple input multiple output (MIMO) channel signals from at least one signal source. The master unit is configured to frequency convert at least one of the MIMO channel signals to a different frequency from an original frequency, and combine the MIMO channel signals for transmission. An optical link couples the master unit with a remote for transceiving the MIMO channel signals. The remote unit is configured to receive the MIMO channel signals to be transmitted over antennas and includes an extension port configured to transceive at least one of the MIMO channel signals. An extension unit is coupled to the remote unit and is configured to frequency convert at least one of the first and second MIMO channel signals from the different frequency back to an original frequency for transmission over an antenna.

Abstract: A segmented optical node exploits a configuration module having arrayed all elements to go from a 1×4 to a 4×4 configuration, save optional redundant switches. A jumper board in the 1×, 2× path configures the node for 1×4 in one orientation and for 2×4 when flipped around 180 degrees. The 4×4 configuration is achieved by rotating the configuration module 90 degrees. In this orientation power to the module is also off, since the 4× configuration is passive.

Abstract: In a PON system in which plural kinds of modulation schemes coexist, when uplink burst signals from respective ONUs are received, the receiving efficiency degrades as the number of the times of switching of the modulation scheme increases. In an optical access (PON) system supporting plural kinds of modulation schemes, an OLT allocates bandwidths for uplink signals, i.e., transmission timings each including a transmission start time and a transmission duration, to ONUs, respectively, such that the bandwidths allocated to plural ONUs for the same modulation scheme are as successive as possible. Based on the transmission timings allocated to the respective ONUs, the OLT switches the modulation scheme of a modulation-scheme variable burst-mode optical transmitter/receiver by control of a modulation scheme controller.

Abstract: A photonic waveform generator and a method of generating an electrical waveform based on a photonic signal are disclosed. The generator includes an input port for receiving an optical signal, a pulse shaper coupled to the input port and configured to Fourier transform the optical signal and apply a pre-distort waveform onto optical spectrum of the optical signal, a dispersive pulse stretcher coupled to the pulse shaper, an optical-to-electrical converter coupled to the dispersive pulse stretcher, and an output port coupled to the optical-to-electrical converter, the pre-distortion removes distortion of the electrical signal that exists in the absence of the pre-distortion caused by violation of far field limitation between the optical signal and the electrical signal.

Abstract: An optical transmission system includes optical transmission apparatuses configured to transmit wavelength-division multiplexed light signals via lightpaths, each of a pair of optical transmission apparatuses includes a conditioning unit configured to adjust the optical intensities of channels included in the wavelength-division multiplexed light signal, and one or more first processors configured to control, based on a conditioning level notified, the conditioning unit; and a managing apparatus configured to manage the pair of the optical transmission apparatuses, the managing apparatus including one or more second processors configured to compute a conditioning level on a basis of system information for respective the pair of optical transmission apparatuses in the optical transmission system.

Abstract: A converged passive optical network (CPON) and a data transmission method are disclosed. The CPON is a combination of a time division multiple access-passive optical network (TDMA-PON) and an orthogonal frequency division multiple access-passive optical network (OFDMA-PON) and is able to dynamically controlling a bandwidth for upstream signal transmission through allocation of multiple subcarriers to each single optical network unit (ONU).