Abstract: [Problem] To determine a time difference between clocks which, for example, are placed far apart from each other with high accuracy at low cost. [Solution] In a time comparison system 20, an intermediate station 21 disperses a single optical signal 21c in the spatial region using the optical complex amplitude modulation to simultaneously transmit the optical signal 21c to a plurality of comparative stations 22 and 23 apart from each other. The intermediate station 21 transmits the optical signal 21c while changing the transmission angle using phase modulation, performs intensity scanning for the reflected light c1 of the optical signal 21c, and detects the peak intensity to determine the directions of the comparative stations 22 and 23.

Abstract: An asynchronous adaptation process includes receiving a first plurality of frames of a first interface group at a first rate, determining idle/stuffing data to be added in each of the first plurality of frames based on a second rate associated with a second plurality of frames of a second interface group, adding information about the idle/stuffing data in each frame of the first plurality of frames in a preceding frame, and transmitting the second plurality of frames of the second interface group with the idle/stuffing data included therein, wherein the second plurality of frames includes the first plurality of frames with the idle/stuffing data.

Abstract: An object is to provide an optical communication system capable of controlling the output ratio by port and by wavelength for incident light of different wavelengths, a method of determining the split ratio of an uneven-split optical splitter for controlling the output ratio by port and by wavelength, and a transmission range determination method for the optical communication system. The split ratio determination method for an uneven-split optical splitter according to the present invention uses the melt-draw distance to adjust the split ratio of each fiber-optic splitter included in the uneven-split optical splitter such that the light output from the farthest ONUs among each of the ports connected under the ports B to M of the uneven-split optical splitter arrives with the minimum reception sensitivity at OLT receivers in a PON system.

Abstract: Artificial neural network systems involve the receipt by a computing device of input data that defines a pattern to be recognized (such as faces, handwriting, and voices). The computing device may then decompose the input data into a first subband and a second subband, wherein the first and second subbands include different characterizing features of the pattern in the input data. The first and second subbands may then be fed into first and second neural networks being trained to recognize the pattern. Reductions in power expenditure, memory usage, and time taken, for example, allow resource-limited computing devices to perform functions they otherwise could not.

Abstract: Systems, methods, and non-transitory computer readable media are configured to determine an optical length of an event in a cable. A physical length of the event in the cable can be determined based on a correlation between optical lengths and physical lengths in the cable. A geographic location of the event can be provided based on the physical length of the event.

Abstract: Techniques for identifying sources of degradations within a PON include detecting that an optical profile of a segment of the PON is outside of a designated operating range, and comparing the drift over time of the segment's optical profile with respective drifts over time of optical profiles of other PON segments, each of which shares an OLT or a last mile termination unit with the segment as a common endpoint. Each segment's optical profile corresponds to characteristics of optical signals delivered over the segment (e.g., attenuation, changes in frequencies, changes in power outputs, etc.). The differences between the segments' drift(s) over time are utilized to determine the source of a degradation within the PON, and may be utilized to identify a particular component of the segment (e.g., the OLT, the last mile termination unit, or an optical fiber included in the segment) as being the source of the degradation.

Abstract: Embodiments of the present invention disclose an optical signal transmission system and an optical signal transmission method. A specific solution is as follows: a first coherent transceiver is configured to: convert N channels of downlink data into N modulating signals, convert the N modulating signals into a first wavelength division multiplexing signal, and send the first wavelength division multiplexing signal to an optical transport unit; the optical transport unit is configured to: receive the first wavelength division multiplexing signal, convert the first wavelength division multiplexing signal into N second optical signals, and correspondingly send the N second optical signals to N second coherent transceivers; and one of the N second coherent transceivers is configured to: receive the N second optical signals, and process the N second optical signals to obtain information in downlink data carried in the N second optical signals.

Abstract: An optical communication device may include a driver component, arranged to achieve a driving voltage, and a modulator component, including a laser or arranged to receive light from a laser. The modulator component may be arranged to achieve a modulated light signal modulated based on the driving voltage. The device may include a transmission line arranged to transfer the driving voltage between the driver component and the modulator component. The transmission line may not impedance matched to the driver component, the transmission line may have an impedance which is at least 20% lower than an output impedance of the driver component, and the transmission line may be impedance matched with respect to signal reflections to the modulator component.

Abstract: A passive optical network system includes an optical line terminator (OLT) configured to detect signal strength and a phase of a burst-mode uplink signal from each of optical network units (ONUs) to control the ONUs so as to equalize signal strengths of signals received from the ONUs and configured to control the ONUs so as to adjust a phase of each of the signals received from the ONUs, and the ONUs are each configured to control signal strength and phase of an burst-mode uplink signal and transmit a resultant burst-mode uplink signal under control of the OLT.

Abstract: A system for electromagnetic communication with a vortex beam concurrently conveys multiple topological charges of orbital angular momentum. The system includes a source, at least one vortex-sensing diffraction grating, and an array of photodetectors. The source generates the vortex beam concurrently conveying a respective number of selected topological charges during each of the time intervals. The selected topological charges for each time interval are selected from a set of available topological charges. The selected topological charges for each time interval encode a symbol of data. The vortex-sensing diffraction grating combines a vortex phase pattern and a linear phase pattern. The vortex sensing diffraction grating produces a diffraction pattern from diffracting the vortex beam received from the source. The array of photodetectors detects portions of the diffraction pattern and from the detected portions recovers the selected topological charges encoding the symbol of each time interval.

Abstract: Embodiments of systems and methods for a multi-source true random number generator (TRNG) are disclosed. A set of values is generated from each of the sources of randomness and an extractor is applied each of the set of values to produce a set of random values from each source. At least one extractor for at least one of the sources is a multi-radix extractor. The sets of values generated from each source of randomness can be composited to generate a random bitstring as the output of the TRNG.

Abstract: An electro-optic system, the electro-optic system that may include an input port that is configured to receive a bandpass signal that conveys information; wherein the bandpass signal is a radio frequency (RF) signal; an optical carrier source that is configured to generate an optical carrier signal having an optical carrier frequency; at least one electrical bias circuit that is configured to generate at least one electrical bias signal; an electro-optic modulation circuit that is linear at the optical field; a manipulator that is configured to (a) receive the at least one electrical bias signal and the bandpass signal, (b) generate, based on the at least one electrical bias signal and the bandpass signal, at least one modulating signal; wherein the electro-optic modulation circuit is configured to modulate the optical carrier by the at least one modulating signal to provide an output optical signal that comprises at least one optical pilot tone and at least one optical sideband that conveys the information.

Abstract: It is possible to allow a user to easily distinguish between an event at a place to be resolved and an event at a place having no problem on a path of a PON communication network to be measured. A light intensity distribution of return light is processed in a time-series order to detect an event at each position on a network. A parameter N1 relating to the total number of splitters present on a path of the network is specified, the number N2 of detections of the total number of splitters detected as an event is recognized, and in a case where “N1>N2”, a last detected event is associated with one optical splitter and is further displayed as an “uncertain splitter” in distinction from a normal splitter.

Abstract: An optical communication system includes an optical transmitter and one or more processors. The optical transmitter is configured to output an optical signal, and includes an average-power-limited optical amplifier, such as an erbium-doped fiber amplifier (EDFA). The one or more processors are configured to receive optical signal data related to a received power for a communication link from a remote communication system and determine that the optical signal data is likely to fall below a minimum received power within a time interval. In response to the determination, the one or more processors are configured to determine a duty cycle of the optical transmitter based on a minimum on-cycle length and a predicted EDFA output power and operate the optical transmitter using the determined duty cycle to transmit an on-cycle power that is no less than the minimum required receiver power for error-free operation of the communication link.

Abstract: A system for improvement of waveform transmission and event detection includes a first transducer configured to receive acoustic waveforms, and a first transducer processor and transmitter configured to invert the phase of the received waveforms of the first transducer and transmit the inverted waveforms via light to a second transducer. The second transducer is configured to receive light waveforms from the first transducer processor and transmitter, receive acoustic waveforms from the second transducer, convert the first transducer light waveforms and the second transducer acoustic waveforms into electrical waveforms, and transmit a combined electrical waveform onwards.

Abstract: A THz waveguide is described, comprising four conductive wires separated by an air gap, the THz waveguide allowing low-loss and dispersion-free propagation of a THz signal. The system for terahertz polarization-division multiplexing comprises at least two THz sources, a THz waveguide and a THz receiver, wherein said THz waveguide comprises four conductive wires separated by an air gap; THz pulses from the THz sources being coupled into the THz waveguide; the THz waveguide transmitting the THz pulses independently, the THz waveguide operating as a broadband polarization-division multiplexer. The method for terahertz polarization-division multiplexing, comprising multiplexing THz pulses from terahertz sources in free-space, coupling resulting multiplexed THz pulses into a THz waveguide comprising four conductive wires separated by an air gap; and demultiplexing the multiplexed THz pulses after propagation in the waveguide.

Abstract: Operations may include obtaining lists of inter-Network-Element connections (inter-NE connections) between connection points of different network elements included in a network and obtaining lists of internal connections of the network elements included in the list of inter-NE connections. The operations may also include generating, based on the lists of inter-NE connections and the lists of internal connections, a global list of connection points that correspond to the inter-NE connections and the internal connections. Moreover, the operations may include generating, based on the global list of connection points, a plurality of upstream connection chains and a plurality of downstream connection chains with respect to the internal connections. In addition, the operations may include generating a list of end-to-end circuits by combining the respective upstream connection chains and the respective downstream connection chains of each respective internal connection.

Abstract: This application provides an optical processing module and an optical processing apparatus. The optical processing apparatus includes at least two optical processing modules. The optical processing module includes a processing unit, and further includes at least one first interface, at least one second interface, and at least one third interface. Each of at least one first interface is configured to connect to and communicate with an upper-layer device, each of the at least one second interface is configured to connect to and communicate with a user-side device, each of the at least one third interface is configured to connect to and communicate with a third interface of another optical processing module, and the processing unit is configured to process, according to a first control instruction, data received from the at least one first interface and the at least one third interface.

Abstract: Disclosed is a method of registering a new optical network unit (ONU) to be performed by an optical line terminal (OLT). The method includes transmitting a ranging notification message to a centralized unit (CU)/distributed unit (DU) to register the new ONU, receiving scheduling information for registering the new ONU from the CU/DU in response to the ranging notification message, transmitting a serial number request message to a service region in which ONUs are present based on the received scheduling information, and when the serial number response message is received from the new ONU in response to the serial number request message, registering the new ONU that transmits a serial number request message. The transmitting of the serial number request message is performed through a multi-quiet zone of a short period.

Abstract: Embodiments of this application disclose a board, an optical module, a MAC chip, a DSP, and an information processing method. The board in the embodiments of this application includes a media access control (MAC) chip, a digital signal processor (DSP), and an equalizer. The MAC chip is configured to send first information to the DSP at an optical network unit (ONU) online stage, where the first information includes a first ONU identifier. The DSP is configured to receive the first information, and determine a first reference equalization parameter, where the first reference equalization parameter is related to the first ONU identifier. The DSP is further configured to set an equalization parameter of the equalizer to the first reference equalization parameter.