Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for clock synchronizing an optical system and multiple leaf systems. In some implementations, an apparatus includes a receiver comprising: a local oscillator laser providing a local oscillator signal, a detector circuit operable to receive a first optical signal and detect first data carried by the first optical signal based on the local oscillator signal, a reference clock circuit supplying a clock signal, a digital signal processor (DSP) operable to receive the first data and supply a control signal to the reference clock circuit based on the first data, the reference clock circuit being operable to adjust the clock signal based on the control signal; and a transmitter operable to output a second optical signal carrying second data, the second data having an associated rate that is based on the clock signal.

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 active optical cable is disclosed. According to the present disclosure, there is provided an active optical cable, having no complicated structure by obviating the need for a separate monitoring photodetector as was used for a typical optical transceiver, increasing light output-current linearity to improve optical coupling efficiency, generating a library of transmission/reception-related electro-optical characteristics of both optical modules so as to enable light outputted from a light source included in an optical transmitter to maintain high linearity over a wide range of temperatures, thereby reducing power consumption, and being applicable to a multi-level PAM technique involving at least four (4) levels.

Abstract: Disclosed herein is wavelength-division multiplexing (WDM) and demultiplexing with signal entry and exit in a common routing surface to increase channel density. In particular, disclosed is a WDM assembly including one or more common ports and one or more channel sets, with each channel set including one or more channel ports. The WDM assembly includes a first routing surface with a first WDM passband and a second routing surface offset from the first routing surface. The second routing surface is configured to reflect at least one signal passed through the first routing surface back through the first routing surface at a laterally different location. The offset controls a pitch between reflected signals, while maintaining a sufficiently large surface area to ensure proper signal performance and/or structural integrity. Controlling pitch by offset provides higher density routing with smaller channel pitches and/or more channels in a decreased volume.

Abstract: An optical data transmitter comprising two or more serially connected optical modulators, each driven using a respective DAC. The digital signals applied to the individual DACs are produced using different respective subsets of the set of bitstreams representing the digital waveform or data stream to be transmitted, with the bitstream subsets being selected, e.g., such that (i) each of the individual DACs is able to support the digital resolution and sampling rate needed for properly handling the subset of bitstreams applied thereto and (ii) differences between average driving powers applied to different optical modulators are relatively small. In different embodiments, the two or more serially connected optical modulators can be arranged for generating optical communication signals of different modulation formats, e.g., PSK, ASK, PAM, IM, and QAM. Some embodiments can advantageously be used for generating optical communication signals employing constellations of relatively large sizes, e.g.

Abstract: A receiver, method, terminal device, visible light transmissive structure and system for decoding light signals and light signals received in an area of overlap of light rays emanating from different lighting devices, each transmitting unique ID data. Light rays (45, 46, 47) entering the receiver (39) are optically spread apart in longitudinal direction (x) of an array of photodetectors (21). The thus spread light rays (45a, 46a, 47a) are optically diverged and spread further over the radiant active surface (29) of a particular photodetector (22-28), thereby optimizing the amount of light received at a respective photodetector (22-28).

Abstract: A method for managing a multi-wavelength passive optical network, comprising: an optical module extracting a module management signal from a reception signal input from an optical signal interface, where the module management signal carries a management message related to the optical module. The solution can solve the problem that an optical module of a multi-wavelength passive optical network in the related art cannot support the smooth upgrade of a related device to the multi-wavelength passive optical network.

Abstract: The present disclosure provides a protection group superposition switching method, a control apparatus, and an optical communication device. Multiple protection state machines are implemented by using a field programmable gate array (FPGA). Each protection state machine independently performs an automatic protection switching (APS) protocol operation for at least one protection group that is pre-associated with the protection state machine. At least one protection status table for recording a status of each protection group is updated according to a result of the APS protocol operation, and a cross-connection table for traffic cross-connection between communication units is updated according to the protection status table; the updated cross-connection table is configured into a cross-connection chip, so that the cross-connection chip performs traffic cross-connection according to the updated cross-connection table.

Abstract: An optical transmission device includes a light source that is driven according to a multicarrier modulation signal in which data is allocated to a plurality of subcarriers to transmit an optical multicarrier modulation signal to another optical transmission device, and a control unit that controls a driving condition of the light source, based on the number of bits allocatable to each of the subcarriers of the multicarrier modulation signal, the number of bits being determined according to transmission characteristics of the optical multicarrier modulation signal in the other optical transmission device.

Abstract: An active optical cable (AOC) is disclosed. According to the present disclosure, an AOC, when connected to a network equipment, generates, changes or deletes and then transmits new information necessary for the a network equipment to recognize and operate the AOC itself, and thereby enabling a data center provided with the AOC and the network equipment to perform data communication smoothly without failure.

Abstract: In some embodiments, an apparatus includes an optical transmitter module that can be electrically coupled to an electrical serializer/deserializer and a controller. The optical transmitter module can include an electrical detector that can receive an in-band signal. The electrical detector can send to the controller a first power error signal and a second power error signal based on the in-band signal. The controller can send a correction control signal to the electrical serializer/deserializer based on the first power error signal and the second power error signal such that the electrical serializer/deserializer sends a pre-emphasized signal to the optical transmitter module based on the correction control signal. In such embodiments, the first power error signal, the second power signal and the correction control signal are out-of-band signals.

Abstract: Disclosed is an information transmission method and device, and a computer storage medium. The method is applied to a local end in a flexible Ethernet (FlexE) network structure and includes: when receiving an information block of a FlexE frame, acquiring, by the local end, bit error state information in the received information block according to a preset acquisition policy; storing, by the local end, the bit error state information at a preset position in a FlexE protocol overhead frame; and transmitting, by the local end, the FlexE protocol overhead frame storing the bit error state information to an opposite end.

Abstract: A coherent optical receiver for AM optical signals has a photonic integrated circuit (PIC) as an optical front-end. The PIC includes a polarization beam splitter followed by two optical hybrids each followed by an opto-electric (OE) converter. Each OE converter includes one or more differential detectors and one or more squaring circuits, which outputs may be summed. The PIC may further include integrated polarization controllers, wavelength demultiplexers, and/or tunable dispersion compensators.

Abstract: An intelligence-defind optical tunnel network system includes a first tier network and a second tier network. The first tier network includes multiple pods, any one of which includes multiple Optical Add-Drop Sub-systems (OADS) configured to transmit data between corresponding servers through ToR switches. The second tier network includes multiple Optical Switch Interconnect Sub-systems (OSIS). Any two of the OSISs transmit a corresponding lateral optical signal via a first line correspondingly. Any two adjacent OSISs are coupled to the OADSs in the same pod of the first tier via multiple optical paths respectively.

Abstract: Communication of light signals and optical cables can be managed to mitigate error associated with using optical cables to communicate light signals. A communication management component (CMC) can embed respective timing synchronization pulses in respective lights signals having respective wavelengths. The light signals can be typical light signals or can be squeezed and twisted to generate a desired twisted light signal. The light signals can be transmitted via the optical cable to a receiver. A CMC, at the receiver end, can determine error associated with the transmission of the light signals via the optical cable and respective characteristics of the respective light signals, including respective arrival times of the respective timing synchronization pulses and respective light intensity or power levels of the respective light signals. From the respective characteristics, CMC can determine a compensation action to perform mitigate the error with regard to subsequent transmissions of light signals.

Abstract: Disclosed herein are methods, devices, and systems for providing timing and bandwidth management of ultra-wideband, wireless data channels (including radio frequency and wireless optical data channels). According to one embodiment, a hub apparatus is disclosed for providing out-of-band bandwidth management for a free-space-optical (FSO) data channel associated with a first device. The hub apparatus includes a processor, a memory coupled with the processor, an FSO transmitter coupled with the processor, and an FSO receiver coupled with the processor. The FSO transmitter may be configured to transmit a control signal comprising timing information and bandwidth management information.

Abstract: An optical communication access point comprises: an optical communication channel for allowing wireless light communication with a remote device, and a memory for storing content, wherein the content in the memory is accessible by the remote device via the wireless light communication link.

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: Disclosed herein is a method for transmitting digital data in a super channel, in which a set of carriers are packed in a predetermined bandwidth. The set of carriers comprises higher and lower edge carriers having the highest and lowest wavelengths, respectively, among said set of earners, wherein data is transmitted via the higher and lower edge carriers using a corresponding modulation format, each modulation format using a constellation diagram comprising a number of symbols, wherein a binary address is associated with each symbol.

Abstract: A method and apparatus of fiber nonlinear noise monitoring and an optical receiver is provided. The method includes: acquiring a training set including at least two received signal samples obtained after a transmitting signal passes different simulation transmission scenarios, calculating amplitude noise feature values after a digital signal processing, calculating statistics values of fiber nonlinear noises, marking the amplitude noise feature values; taking the amplitude noise feature values as input of a noise monitoring model, taking marks to which the amplitude noise feature values correspond as target output, and training the noise monitoring model according to samples in the training set, so as to obtain a trained noise monitoring model, and inputting a plurality of amplitude noise feature values of received signals to be monitored into the trained noise monitoring model, so as to obtain statistics values of fiber nonlinear noises to which the received signals to be monitored correspond.