Abstract: Devices and techniques for integrated optical data communication. A method of encoding symbols in an optical signal may include encoding a first symbol by injecting charge carriers, at a first rate, into a semiconductor device, such as a PIN diode. The method may also include encoding a second symbol by injecting charge carriers, at a second rate, into the semiconductor device. The first rate may exceed the second rate. A modulator driver circuit may include a resistive circuit coupled between supply terminal and drive terminals. The modulator driver circuit may also include a control circuit coupled between a data terminal and the resistive circuit. The control circuit may modulate a resistance of the resistive circuit by selectively coupling one or more of a plurality of portions of the resistive circuit to the drive terminal based on data to be optically encoded.

Abstract: Optical fiber-based wireless systems and related components and methods are disclosed. The systems support radio frequency (RF) communications with clients over optical fiber, including Radio-over-Fiber (RoF) communications. The systems may be provided as part of an indoor distributed antenna system (IDAS) to provide wireless communication services to clients inside a building or other facility. The systems incorporate various functions, such as optical network terminal (ONT), splitter, and local powering, in antenna coverage areas.

Abstract: There is provided a method to discriminate NLE-induced signal deformation from ASE-noise on polarization multiplexed signals, in order to measure the OSNR under NLE conditions and/or characterize the NLE-induced signal deformation. In accordance with one aspect, the method is based on the acquisition of optical spectrum traces when the (data-carrying) optical communication signal is partially or completely extinguished (ASE-noise only), as well as with a live optical communication signal. Comparing traces acquired with different conditions and/or at different dates allows discrimination of the signal contribution, the ASE-noise contribution and the NLE-induced deformations on the SUT.

Abstract: Embodiments of the present invention provide a link switching method, device, and system. The method comprises: an optical network unit (ONU) transmits a monitoring packet through a first Maintenance association End Point on a first link connected to the ONU and an aggregation side switch device, so as to monitor the first link; the ONU performs switching from a first sub-link of the first link to a first sub-link of a second link if it is detected that a link fault occurs on the first link; the ONU sends a notification message to a second optical line terminal (OLT), so that the second OLT enables a transmission port; and the ONU sends an automatic protection switching message to the aggregation side switch device through a second Maintenance association End Point on the second link.

Abstract: A system that incorporates teachings of the subject disclosure may include, for example, a central controller that performs operations including monitoring multiple network nodes, at least some of the network nodes being in communication with others through respective point-to-point links. Each point-to-point link includes a respective free space optical channel. The central controller detects optical received signal strength of a free space optical channel falling below a certain level and provides control signals to reconfigure the multiple network nodes. Signals are re-routed along one of the respective point-to-point links through other network nodes responsive to detecting the optical received signal strength falling below the certain level Other embodiments are disclosed.

Abstract: Methods and apparatus for interference cancelation in a radio frequency communications device are described. In various embodiments a signal to be transmitted in converted into an optical signal and processed using an optical filter assembly including one or more optical filters to generate an optical interference cancelation signal. The optical interference cancelation signal is converted into an analog radio frequency interference cancelation signal using an optical to electrical converter prior to the analog radio frequency interference cancelation signal being combined with a received signal to cancel interference, e.g., self interference. The optical filter assembly can include a large number of taps, e.g., 30, 50, 100 or more. Each tap may be implemented as a separate optical filter or series of optical filters. Delays and/or gain of the optical filters can be controlled dynamically based on channel estimates which may change due to changes in the environment and/or communications device position.

Abstract: An optical data circuit includes threshold adjustment circuits to perform threshold adjustment compensation of asymmetrical optical noise. The optical data circuit includes an optical-to-electrical conversion circuit configured to produce first and second differential electrical data signals, at respective first and second electrical nodes, in response to an optical data signal. First and second digital-to-analog converter (DAC) circuits are each respectively coupled to the first and second electrical nodes and configured to respectively generate first and second adjustment signals. The first and second DAC circuits are configured to adjust the first and second differential electrical data signals such that a zero-crossing point of positive data is pulled up in response to the first adjustment signal and a zero-crossing point of negative data is pulled down in response to the second adjustment signal.

Abstract: An optical transmitter including a signal processor, a driver, a current detector, an amplitude detector, and a controller is disclosed. The signal processor outputs a modulation signal that has first amplitude. The driver amplifies the modulation signal for generating a driving signal that has second amplitude. The current detector detects a supply current that the driver consumes for the amplification. The amplitude detector detects the second amplitude of the driving signal. The controller keeps the driver based at least in part on the supply current detected by the current detector for maintaining the supply current of the driver in a first target value. The controller varies the first amplitude of the modulation signal based at least in part on the second amplitude of the driving signal detected by the amplitude detector for maintaining the second amplitude of the driving signal in a second target value.

Abstract: A networked speaker system communicates using Li-Fi. The LEDs implementing the Li-Fi may also have modes in which they are used to map the walls of a room in which the speakers are located, detect the locations of speakers in the room, and detect and classify listeners in the room. Based on this, waveform analysis may be applied to input audio to establish equalization and delays that are optimal for the room geometry, speaker locations, and listener locations.

Abstract: Systems for communication in a rotary joint. In one example, a communication system includes a stator, a rotor, a plurality of optical receivers circumferentially disposed at a first radius of one of the stator and the rotor, a plurality of optical transmitters circumferentially disposed at a second radius of the other of the stator and the rotor, each optical transmitter of the plurality configured to transmit a data signal to a corresponding optical receiver of the plurality of optical receivers, and a plurality of optical elements, individual optical elements having one of a first size and a second size, wherein individual optical elements are interposed between each optical transmitter of the plurality of optical transmitters and each optical receiver of the plurality of optical receivers and arranged so as to alternate between the first size and the second size along one of the first radius and the second radius.

Abstract: Methods and systems are disclosed for storing, in a non-transitory memory device, multi-layer network information comprising at least one of link availability, bandwidth availability, priority levels for paths in a multi-layer network, path status in the multi-layer network, and status for network elements in the multi-layer network; receiving, via at least one input component, a message from a network element in the network comprising information indicative of a failure of a working path in the network; determining, automatically, based at least in part on the multi-layer network information, an alternate path for transmission of the data traffic through the network; and transmitting, via at least one output component, at least one signal comprising configuration instructions to at least one optical line module, the configuration instructions directing the optical line module to switch and select the data traffic using the alternate path.

Abstract: An optical communication module includes a module board housed in a casing, a VCSEL and a driving IC mounted on a mounting surface of the module board, a lens holder mounted on the mounting surface of the module board, a lens block held by the lens holder, a plurality of thermal vias passing through the module board, and a first fixing screw and a second fixing screw passing through the module board to be screwed into the casing so as to press a back surface of the module board against a bottom surface of the casing, and the first fixing screw and the second fixing screw are each arranged in a region between the plug connector and the lens holder and on either outer side of the lens holder.

Abstract: The locking of optical carriers to a grid can be achieved by employing an optical filter that exhibits athermal behavior in a frequency range to lock at least the frequency of a first channel to a target frequency. The locked frequency may be used to tune and lock the location of the free spectral range of a bandpass filter having transmission peaks at intervals, e.g., an FSR, corresponding to the target grid. The bandpass filter is used generate feedback signals that are used to lock the remaining frequencies to the grid. The athermal filter may be integrated on a silicon photonic integrated circuit.

Abstract: A reconfigurable free-space optical inter-rack network includes a plurality of server racks, each including at least one switch mounted on a top thereof, where each top-mounted switch includes a plurality of free-space-optic link connector, each with a free-space optical connection to a free-space-optic link connector on another top-mounted switch, a single ceiling mirror above the plurality of server racks that substantially covers the plurality of server racks, wherein the single ceiling mirror redirects optical connections between pairs of free-space-optic link connectors to provide a clear lines-of-sight between each pair of connected free-space-optic link connectors, and a controller that preconfigures a free-space optical network connecting the plurality of server racks by establishing connections between pairs of free-space-optic link connectors, and that reconfigures connections between pairs of free-space-optic link connectors in response to network traffic demands and events.

Abstract: Embodiments relate to providing simultaneous digital and analog services in optical fiber-based distributed radio frequency (RF) antenna systems (DASs), and related components and methods. A multiplex switch unit associated with a head-end unit of a DAS can be configured to receive a plurality of analog and digital downlink signals from one or more sources, such as a service matrix unit, and to assign each downlink signal to be transmitted to one or more remote units of the DAS. In one example, when two or more downlink signals are assigned to be transmitted to the same remote unit, a wave division multiplexer/demultiplexer associated with the multiplex switch unit can be configured to wave division multiplex the component downlink signals into a combined downlink signal for remote side transmission and to demultiplex received combined uplink signals into their component uplink signals for head-end side transmission.

Abstract: A fiber optic-based communications network includes: a power insertion device, connected to multiple fiber links from a data source, configured to provide power insertion to a hybrid fiber/power cable connected to at least one fiber link of the multiple fiber links; the hybrid fiber/power cable, connecting the power insertion device to a connection interface device, configured to transmit data and power from the power insertion device to the connection interface device; and the connection interface device, configured to provide an interface for connection to an end device via a power over Ethernet (PoE)-compatible connection and to provide optical to electrical media conversion for data transmitted from the power insertion device to an end device via the hybrid fiber/power cable and the PoE-compatible connection.

Abstract: A system that performs heterodyne optical imaging across multiple platforms gathers an optical signal from an optical sensor at each of the multiple platforms. At the same time, an optical frequency comb local oscillator (LO) at each of the platforms generates a reference comb signal comprising a set of optical frequency comb lines at different frequencies, wherein each optical frequency comb LO is locked to a local atomic clock at each of the platforms. Next, a mixer, at each of the platforms, is used to mix the optical signal gathered from the optical sensor with the reference comb signal generated by the optical frequency comb LO to generate a mixed signal. The system then communicates the mixed signals generated at each of the platforms to a central location. Finally, the system correlates the mixed signals received from each of the platforms and generates a reconstructed optical image.

Abstract: A visible light signal transmitting method includes: determining a luminance change pattern to transmit the visible light signal; switching a common switch according to the luminance change pattern, the common switch being for turning ON a plurality of light sources in common; and turning ON a first pixel switch, to cause the first light source to be ON for a period in which the common switch is ON and the first pixel switch is ON, to transmit the visible light signal, the first light source being one of the plurality of light sources. In the turning ON of a first pixel switch, when the image is displayed on the display, the first pixel switch is switched to increase a lighting period that corresponds to the first light source, to compensate a period in which the first light source is OFF for transmission of the visible light signal.

Abstract: An optical transceiver includes a main board, a fiber joint, a circuit board, a transfer board, metal traces, photoelectric elements, a lens set, a connection base, and an amplifier. The fiber joint is coupled to the lens set and connection base for positioning plural optical fibers. The connection base is coupled to the main board, and the circuit board is electrically connected to the main board. The transfer board is disposed between the fiber joint and circuit board. Each of the metal traces is arranged on both of two neighboring surfaces of the transfer board. The photoelectric elements are respectively coupled to metal traces on the surface of the transfer board facing the fiber joint, and axially aim to the optical fibers, respectively. The amplifier electrically connects the circuit board and the photoelectric elements via the metal traces.

Abstract: A transmitter optical module that implements with two or more laser diodes (LDs) therein is disclosed. The LDs are mounted on a common sub-mount independent of driving circuits and driven by the driving circuits in the shunt-driving mode. The cathode of the LDs are independently, namely, isolated from the ground of the neighbor LDs, connected to the ground within the driving circuits but floated from the chassis ground.