Abstract: An underwater communications network may include spaced apart nodes on a bottom of a body of water. The underwater communications network may also include fiber optic cabling connecting the spaced apart nodes. Each node may include a frame, a node short-range navigation device carried by the frame, and an unmanned underwater vehicle (UUV) carried by the frame after delivering a fiber optic cable along a navigation path from an adjacent node. The UUV may be configured to cooperate with the node short-range navigation device during an end portion of the navigation path adjacent the frame.

Abstract: Embodiments of this application disclose an optical switch. The optical switch includes at least one first port, at least one second port, a first wavelength division multiplexing WDM apparatus, an optical splitter, an optical monitoring apparatus, and an optical switching apparatus. The first port is configured to transmit an input first optical signal to the first WDM apparatus, where the first optical signal is a multi-wavelength signal. The first WDM apparatus is configured to demultiplex the first optical signal. The optical splitter is configured to split a demultiplexed first optical signal to obtain a first sub-signal and a second sub-signal. The optical switching apparatus is configured to perform optical switching on the first sub-signal. The second port is configured to output a first sub-signal obtained after optical switching. The optical monitoring apparatus is configured to perform optical performance monitoring on the second sub-signal.

Abstract: Systems and methods are provided for improving signal propagation using lasers. A laser device is used to clear the air between a first fixed station, such as a base station, and a second fixed station, such as a fixed wireless access device. In the wake of the laser, particles in the air interface are cleared along a path that can then be used to communicate one or more sets of wireless signals. In the wake of the laser, the wireless signals experience less absorption, reflection, and refraction, reducing path loss, and increasing the overall effectiveness of the wireless system—particularly at or near the cell edge or when a meteorological condition exists between the fixed stations.

Abstract: A method, system, and apparatus for multiplexing comprising feeding a signal into a sampler, splitting a first signal into an even branch at a first set of times, splitting a second signal into an odd branch at a second set of times, feeding a switch bleed current into the first branch at the second set of time and feeding the switch bleed current into the second branch at the first set of time.

Abstract: An electronic device may include wireless circuitry clocked using an electro-optical phase-locked loop (OPLL) having primary and secondary lasers. A frequency-locked loop (FLL) path and a phase-locked loop (PLL) path may couple an output of the secondary laser to its input. A photodiode may generate a photodiode signal based on the laser output. A digital-to-time converter (DTC) may generate a reference signal. The FLL path may coarsely tune the secondary laser based on the photodiode signal until the secondary laser is frequency locked. Then, the PLL path may finely tune the secondary laser based on the reference signal and the photodiode signal until the phase of the secondary laser is locked to the primary laser. The photodiode signal may be subsampled on the PLL path. This may allow the OPLL to generate optical local oscillator signals with minimal jitter and phase noise.

Abstract: An apparatus for subsea environment sensing. In one aspect, the apparatus may include a repeater assembly, disposed in an optical repeater; and an environmental sensor assembly, disposed proximate to the repeater assembly, the environmental sensor assembly being coupled to receive power from the repeater assembly over an optical link.

Abstract: A spectrally multiplexed quantum repeater (SMuQR) based on spatially arrayed nodes of frequency-multiplexed multi-qubit registers uses the natural inhomogeneous distribution of optical transition frequencies in solid state defect centers. This distribution enables spectrally selective, individual addressing of large numbers of defect centers within an optical diffraction limited spot along a long cavity or waveguide. The spectral selection relies on frequency shifting an incident optical field at a rate as fast as once per defect center lifetime. The defect centers are resonant at visible frequencies and emit visible single photons which are down-converted to a wavelength compatible with long-distance transmission via conventional optical fiber. The down-converted photons are all at the same telecommunications wavelength, with the different spectral bins mapped to different temporal bins to preserve the multiplexing in the time domain, for distribution to other nodes in the quantum network.

Abstract: In order to readily carry out communication between terminal stations, a submarine optical communication system includes a first terminal station including a first monitoring means for monitoring the signal quality of dummy light a first dummy light source that outputs dummy light to the second terminal station, and a first light transmitting means for transmitting an optical signal to the second terminal station, the optical signal including a first signal quality of the dummy light; and the second terminal station including a second dummy light source that outputs dummy light to the first monitoring means, a second monitoring means for monitoring the signal quality of the dummy light, and a light receiving means for receiving the optical signal.

Abstract: A communication system may an optical signal generator and a signal path. The generator may generate one or more optical local oscillator (LO) signals and an optical frequency comb. Optical paths and an optical demultiplexer may distribute the optical LO signal(s) and the frequency comb to photodiodes in one or more access points. The photodiodes may be coupled to antenna radiating elements. The optical paths may illuminate each photodiode using a signal pair that includes one of the optical LO signals and one of the carriers from the frequency comb. The photodiodes may convey wireless signals using the antenna radiating elements at frequencies given by the differences in frequency between the signals in the signal pairs. The radiating elements may concurrently convey the wireless signals with different external devices at different frequencies, with different devices at the same frequency, and/or with the same device at the same frequency.

Abstract: An optical communication system includes an optical line terminal and a plurality of optical network units connected by optical transfer paths. The optical line terminal includes a light transmitting/receiving unit and a control unit. The light transmitting/receiving unit transmits/receives an optical signal to/from the plurality of optical network units via the optical transfer paths. The control unit performs control to change a launch power of an optical signal transmitted from the light transmitting/receiving unit, such that, when, regarding at least one optical network unit, a monitoring value has changed to a value indicating deterioration, a receive power of an optical signal in each of the plurality of optical network units is lower than or equal to an upper limit value and a receive power of an optical signal in the optical network unit in which the monitoring value has changed is higher than or equal to a lower limit value.

Abstract: Systems and methods are described for transmitting information optically. For instance, a system may include an optical source configured to generate a beam of light. The system may include at least one modulator configured to encode data on the beam of light to produce an encoded beam of light/encoded plurality of pulses. The system may include a spectrally-equalizing amplifier configured to receive the encoded beam of light/encoded plurality of pulses from the at least one modulator and both amplify and filter the encoded beam of light/encoded plurality of pulses to produce a filtered beam of light/filtered plurality of pulses, thereby spectrally equalizing a gain applied to the encoded beam of light. In some cases, the system may slice the beam of slight, to ensure a detector has impulsive detection. In some cases, the system may include a temperature controller to shift a distribution curve of wavelengths of the optical source.

Abstract: There is provided a method including receiving an incoming ID at a first wearable heads-up display (WHUD), which incoming ID is associated with a communicant device. The method also includes sending match data from the first WHUD to a match engine. The match data includes a first WHUD ID and the incoming ID. Moreover, the method includes receiving a match indicator at the first WHUD from the match engine. The match indicator is to indicate a match event between the first WHUD and the communicant device based on the match data. Furthermore, the method includes effecting communication between the first WHUD and the communicant device comprising at least one of sending a message from the first WHUD to the communicant device and receiving at the first WHUD a corresponding message from the communicant device. The first WHUD, and a method of operating the match engine are also described.

Abstract: An Optical Wireless Communication (OWC) receiver configured to receive an incoming optical beam modulated with data and output an output signal including the modulated data. A lens receives the incoming optical beam. Photodiodes positioned at a distance from the lens and proximal to the focal plane of the lens receive a fraction of the incoming optical beam and generate a photocurrent in correspondence with photons received. The photodiodes are provided in a two-dimensional array including rows and columns wherein outputs of the columns are combined and their photocurrents are summed. An amplifier connected to the combined output of the columns converts the summed photocurrents into an output signal. Interconnections of the photodiodes form at least two parallel branches wherein each branch includes a cascade of at least two photodiodes forming a combined photodetector surface.

Abstract: Devices, systems, and methods for providing wireless personal area networks (PANs) and local area networks (LANs) using visible and near-visible optical spectrum. Various constructions and material selections are provided herein. According to one embodiment, a free space optical (FSO) communication apparatus includes a digital data port, an array of light-emitting diodes (LEDs) each configured to have a transient response time of less than 500 picoseconds (ps), and current drive circuitry coupled between the digital data port and the array of LEDs.

Abstract: A visual light communication system is disclosed.

Abstract: The invention relates to an arrangement for controlling electrical gadgets, which comprises at least one master device and a slave switch device; or at least one master device and a slave socket device; or at least two master devices, as long as at least one of them is a switch-type device; or any of the master and switch devices and an external control. The arrangement for controlling electrical gadgets provides safety to the user and a substantial energy saving while generating comfort for the user.

Abstract: A communication system has a plurality of LEO satellites in a specified orbital plane and a plurality of trunk satellites in a medium earth orbit. Each LEO satellite acquires satellite-specific data and includes inter-satellite links with adjacent LEO satellites. Each trunk satellite includes inter-satellite links adjacent trunk satellites. One of the trunk satellites operates as a relay trunk satellite in position to maintain optical communication with a specified ground station on the Earth. Each LEO satellite has a limited field of regard to establish optical communication with any trunk satellite. A relay LEO satellite is configured to establish optical communication with a corresponding trunk satellite. The plurality of LEO satellites relay aggregated data to the relay LEO satellite. The relay LEO satellite relays the aggregated data to the corresponding trunk satellite. The relay trunk satellite relays the received aggregated data to the corresponding ground station.

Abstract: An optical receiver includes an optical amplifier that amplifies a received optical signal containing multiple wavelengths, a monitor circuit that monitors light intensities of the demultiplexed optical signal, a processor, and a memory having information representing a relationship between a total incident light intensity of the optical signal incident onto the optical amplifier and gains of the optical amplifier for the respective wavelengths.

Abstract: A method of identifying a fault in an optical link comprises continually storing samples of a signal that represents a power of an optical signal received over the optical link. When a fault is detected on said optical link, at least one stored series of samples of the signal is retrieved. The method then comprises performing a classification on the retrieved series of samples, in order to classify the series of samples as resulting from one of a plurality of predefined faults.

Abstract: An access network includes a first local network node configured to serve one or more first client devices according to a first network protocol, a second local network node configured to serve one or more second client devices according to a second network protocol different than the first network protocol, and a hub in operable communication with the first and second local network nodes over respective transport media. The hub contains a centralized network node configured to generate a first digitized radio frequency (RF) stream to the first local network node and a second digitized RF stream to the second local network node. The first digitized RF stream corresponds to the first network protocol and the second digitized RF stream corresponds to the second network protocol.