Abstract: Optical receivers including at least one local oscillator providing local oscillator light at a local oscillator center frequency offset from a received optical signal by a frequency difference. A combiner for combining the optical signal with the local oscillator light and to output at least one combined optical signal. An opto-electrical converter down-converts the combined optical signal into corresponding RF electrical signal at the frequency of the frequency difference. A filter may be provided to at least substantially remove one of the upper and lower electrical signal sidebands to output one of a VSB and SSB RF signal before rectification. A local oscillator frequency controller may adjustably control the local oscillator frequency to provide the difference frequency that produces a specified group delay in the RF electrical signal that may be specified via optical receiver performance parameters and/or user input and offset using a group delay filter.

Abstract: A multi-path multi-mode light signal aggregation, transmission, separation apparatus and method are provided. The apparatus includes a shell, an array lens module configured to turn multi-path multi-mode light signals having different frequencies and emitted by an emitting terminal and further totally reflect the light signals to a receiving terminal, an aggregation lens module configured to aggregate the turned light signals into a single-path multi-mode light signal and further disperse the single-path multi-mode light signal into the multi-path multi-mode light signals with different frequencies, and a collimation lens module configured to collimate the aggregated single-path multi-mode light signal to an optical fiber for transmission and to collimate the received single-path multi-mode light signal to the aggregation lens module. The lens modules are arranged on a substrate in the shell. The number of optical fibers and the upgrading cost can be reduced, and the communication rate is increased.

Abstract: An optical transmission apparatus includes the optical transceiver configured to generate a test light for each wavelength assignable to the wavelength multiplex light to transmit the test light to the optical transmission line via the wavelength multiplexer and demultiplexer, detect a reflected light for the test light from the optical transmission line, calculate an arrival distance of the test light for the each wavelength from the reflected light for the each wavelength, and set a wavelength having a longest arrival distance among the arrival distances for the respective wavelengths, as a wavelength to be assigned to the signal light in the optical transceiver.

Abstract: An optical communication system is configured to transmit and receive at least four multiplexed, differently-polarized, optically-transmitted signals. Each signal is associated with a predefined state of polarization. An optical transmitter is configured to transmit multiplexed, differently polarized, optically transmitted signals. An optical receiver is configured to receive the optically transmitted signals. The system includes a multi-polarization analyzer circuit configured to obtain an analyzed signal for each of the polarized signals in Stokes space. The analyzer circuit is configured to determine if the multiplexed signal has been transformed by extreme polarization-dependent loss (PDL), the receiver correcting for the extreme polarization-dependent loss.

Abstract: A system and method for improving for amplifying an electronic signal by using high efficiency amplifiers to amplify one analog or digital signal at a time. The system further improves performance by providing parallel communication pathways throughout the entire transport and distribution chain. By creating parallel processing paths, both optically and electrically, the interaction of multiple signals are limited thereby avoiding unwanted intermodulation and noise.

Abstract: Various apparatuses, circuits, systems, and methods for optical communication are disclosed. In some implementations, an apparatus includes multiple lasers that input an electronic signal. Each laser encodes and outputs a respective optical data signal based on the electronic signal. Each laser has a different configuration of one or more first optical parameters. A first selection circuit selects the respective optical data signal from one of the lasers. Multiple optical components configure second optical parameters of an input optical data signal. A second selection circuit inputs the selected optical data signal from the first selection circuit and provides the selected optical data signal to one of the optical components. A third selection circuit selects the optical data signal output from the one optical component.

Abstract: An optical transmitter, an optical receiver, and an optical transmission method are disclosed. The optical transmitter includes an optical signal generator, N spreaders, N pairs of data modulators, and a combiner, where the optical signal generator generates N optical carriers; an ith spreader spreads an ith optical carrier, to obtain a spread optical signal having two subcarriers; splits the spread optical signal into a first optical signal and a second optical signal; and delays the second optical signal to obtain a third optical signal; an ith pair of data modulators modulate the first optical signal and the third optical signal to obtain a pair of modulated optical signals, transmit the pair of modulated optical signals to the combiner, where the pair of modulated optical signals reaching the combiner differ by 1/(4 fsi) in time domain; and the combiner combines, into one optical signal, N pairs of modulated optical signals.

Abstract: A laser communication network implemented with multi-chroic filters that are able to partition signals from a band of wavelengths into different sub-bands that enable more than one relay terminal to interconnect users (i.e., sources and sinks of traffic) is provided. A band of wavelengths may be partitioned to enable users to communicate with relay satellites, and relay satellites to communicate with one another, using a predefined set of transmission and reception wavelengths regardless of which particular relay is in the communication session. In other words, embodiments support both relay satellites and user satellites by constructing distinct passbands for relay-borne terminals and the same passbands for users.

Abstract: An illustrative SerDes receiver includes: a front-end filter, a precomputation unit, a selection element, and a controller. The front end filter converts a receive signal into a linearly-equalized signal. The precomputation unit accepts the linearly-equalized signal with or without a subtracted feedback signal, and employs a set of comparators with threshold values that depend on a first post-cursor ISI value F1, the set of comparators operating to generate a set of tentative symbol decisions. The selection element derives a selected symbol decision from each set of tentative symbol decisions, thereby deriving a sequence of symbol decisions from the receive signal. The controller constrains F1 if the receive signal uses a PAM4 signal constellation, setting F1 to equal zero if the receive signal is conveyed via a low-loss channel and to equal one if the receive signal is conveyed via a high-loss channel.

Abstract: Methods and systems relating to administration of authentication information for electronic access control are disclosed. Authentication information is conveyed to an electronic locking device configured to restrict access to an entry point. In various embodiments, a smart device comprises a display screen for presenting a machine-readable optical code comprising encoded authentication information. An image sensor of the electronic locking device can decode the machine-readable optical code to obtain the authentication information. The electronic locking device is configured to permit access to the entry point in response to the image sensor detecting a machine-readable optical code corresponding to an access credential. A server device can provide authentication information to the smart device based on an access criterion. Conveying authentication information to the locking device may include rendering a webpage comprising the machine-readable optical code corresponding to the access credential.

Abstract: A method of obtaining a measure of asymmetry between optical fibers of a forward and reverse paths is provided in order to synchronize clocks of optical nodes connected by asymmetrical optical fiber paths. The method includes receiving, at first and second arrival times, from a first optical network device, a first optical signal transmitted on a first optical fiber and a second optical signal transmitted on a second optical fiber, calculating a first time difference between the second arrival time and the first arrival time. The method includes determining a measure of asymmetry between the first optical fiber and the second optical fiber based on the first time difference and a second time difference between a first time of transmission by the first optical network device of the first optical signal and a second time of transmission by the first optical network device of the second optical signal.

Abstract: A method for transmitting data from an electronic device to an electronic watch, including the following steps: emitting a sequence of light signals with a light source of the electronic device, each signal having a light-intensity level belonging to a set of at least four light-intensity levels, said sequence corresponding to a code of the data to be transmitted; detecting successive light-intensity levels with a phototransistor of the watch, so as to reconstitute the sequence; and decoding the sequence in order to reconstitute the data, the set of at least four intensity levels being divided into a first portion and a second portion, one light signal in two of the sequence having a light-intensity level belonging to the first portion, the other signals having a light-intensity level belonging to the second portion.

Abstract: Systems and methods are provided for controlling one or more optical amplifiers of a C+L band photonic line system of a telecommunications network in which C-band signals and L-band signals may be transmitted. In one implementation, a control device may include a processing device and a memory device configured to store a traffic managing module for controlling C-band and the L-band traffic in the photonic line system. The traffic managing module, when executed, may be configured to cause the processing device to calculate a gain correction profile based on a difference between a saved baseline transmission profile and a measured transmission profile of a surviving band of a photonic line system when another band of the photonic line system is missing or impacted. The traffic managing module is configured to apply the gain correction profile to a respective optical amplifier of the photonic line system to compensate for the difference.

Abstract: Provided are a method and system for implementing an SDO function, and a SDON system.

Abstract: A cover for an electronic circuit package, including: a body having an opening extending therethrough; a first element located in the opening and having a surface continuing planar or rounded shapes of a surface of the cover; and a second element of connection of the first element to the body.

Abstract: Techniques for determining an alternative communication mode for vehicle-to-vehicle communication at a host vehicle can include monitoring the primary mode of RF communication to ensure it is effectively communicating and, if not, intelligently selecting a backup communication mode comprising one or more other sensors and/or systems of the vehicle. The selection of the backup communication mode may take into account various factors that can affect the various modes of communication from which the backup communication mode is selected.

Abstract: An optical interconnect computing module having free space optical interconnects that form communication links with other systems with like optical interconnects and with computer blades contained within the computing module. The computing module adapts to changes in the position and orientation and other factors of the optical interconnects. The optical interconnects utilize solid-state electronic and optoelectronic components and optical components. The ability to adapt is controlled by an algorithm implemented in software, firmware and logic circuits. Computing modules within an equipment rack and between equipment racks as well as blades contained within a computing module may experience changes in position and orientation due to installation misalignment, servicing of equipment, vibrations, floor sagging, thermal expansion and contraction, earthquakes, line-of-sight obstructions, manufacturing imperfections and other sources.

Abstract: An optical signal modulated with a stream of symbols comprising a sequence of training symbols is received at a receiver. First equalizer circuitry calculates and applies first coefficients to digital signals representative of the optical signal, thereby resulting in first compensated signals. Second equalizer circuitry calculates second coefficients based on a correlation between the first compensated signals and digital signals representative of the sequence of training symbols and applies the second coefficients to the first compensated signals, thereby resulting in second compensated signals. Third equalizer circuitry calculates and applies third coefficients to the second compensated signals, thereby resulting in third compensated signals. The first, second, and third coefficients compensate for impairments in the optical signal varying at respective first, second, and third rates, where the third rate is higher than the first rate and lower than the second rate.

Abstract: A station placed on a high-altitude stationary platform includes two main emitter/receiver sets, each configured to establish a main communication link with a remote terminal station or with another station placed on a high-altitude stationary platform and two backup emitter/receiver sets, each configured to establish a backup communication link with a repeater placed on a relay station on the ground or at sea or with a remote terminal station, the station furthermore comprising a control facility configured to selectively activate a main communication link or a backup communication link as a function of an indicator of the operating state of the main communication link.

Abstract: Embodiments of the present disclosure provide a method and device of signal processing in optical fiber communication systems. The method includes dividing electrical signals for a plurality of receivers in the optical fiber communication system into a plurality of groups, the plurality of groups each being associated with at least one of the plurality of receivers. The method also includes obtaining time-domain multiplexed signals by multiplexing the electrical signals in the plurality of groups in time domain. The method also includes multiplexing the time-domain multiplexed signals in the plurality of groups in frequency domain such that the time-domain multiplexed signals occupy respective sub-bands of a transmission bandwidth for the optical fiber communication system. The method also includes converting the frequency-domain multiplexed signals into analog optical signals for transmission.