Abstract: A distributed sensing apparatus based on Optical Time Domain Reflectometry, OTDR, including an optical source; an optical splitter in optical communication with the optical source, the optical splitter having first and second outputs; a sensing fibre in optical communication with the first output of the optical splitter; a combining unit arranged to combine a reference signal derived from the second output of the optical splitter with a backscattered signal derived from the sensing fibre, wherein the combining unit comprises one or more 3×3 fused fibre couplers; and a signal processing unit configured for processing information derived from the combining unit so as to provide distributed sensing data. The combining unit includes a polarization diversity arrangement including one or more polarization sensitive elements.

Abstract: An adaptive optical apparatus includes a first deformable mirror that includes a reflecting surface reflecting light propagated through an atmosphere, and a drive unit having a plurality of drive elements and changing an uneven shape of the reflecting surface, a second deformable mirror that includes a reflecting surface reflecting the light from the first deformable mirror and a drive unit having a plurality of drive elements and changing an uneven shape of the reflecting surface, a detector that detects light intensity of the light from the first deformable mirror and the second deformable mirror, and a controller that controls the drive unit of each of the first deformable mirror and the second deformable mirror. The controller is configured to execute a first update operation of controlling the drive unit of one deformable mirror based on a detected value by the detector.

Abstract: A coherent optical transmitter is in operable communication with an optical fiber an includes a plurality of analog-to-digital converters (ADCs) configured to (i) receive a plurality of radio frequency analog input signals, respectively, and (ii) convert the received plurality of RF analog input signals into a plurality of respective digital data streams. The transmitter further includes a source laser configured to output at least two orthogonal polarization component signals, and at least two polarization modulators configured to modulate (i) an in-phase portion output from a first ADC, (ii) an in-quadrature portion output from a second ADC, and (iii) one polarization component signal of the at least two orthogonal polarization component signals. The transmitter further includes a polarization beam combiner configured to (i) multiplex the respective outputs of the at least two polarization modulators, and (ii) transmit the multiplexed output from the polarization beam combiner to the optical fiber.

Abstract: A method and corresponding apparatus for reducing a backlight crosstalk impact of an optical assembly. The method comprises: sequentially presetting two drive currents of a laser corresponding to a target wavelength channel as a first and second drive currents, respectively collecting backlight crosstalk data of the target wavelength channel to other wavelength channels, and generating a first and second crosstalk data matrix; carrying out fitting on the first and second crosstalk data matrix to acquire a crosstalk data calibration matrix; and calculating target backlight data of the target wavelength channel according to the crosstalk data calibration matrix, to calculate front light transmitting power of the target wavelength channel according to the target backlight data, thereby monitoring the optical assembly according to the front light transmitting power. The crosstalk impact can be reduced without an additional optical element, thereby improving accuracy of backlight detection and saving costs.

Abstract: An object to provide a submarine optical transmission apparatus capable of efficiently housing optical components and electric components. A submarine optical transmission apparatus includes a case, an electric component housing unit, and an optical component housing unit. The electric component housing unit and the optical component housing unit can house either or both of an optical component and an electric component and are stacked in a Z-direction. The case can house the electric component housing unit and the optical component housing unit that are stacked, and a longitudinal direction thereof is an X-direction.

Abstract: An optical line terminal (OLT) detects content distribution conditions in terminals, and performs control for performing switching to distribution to each terminal using an individual virtual local area network (VLAN) or distribution to a plurality of terminals by broadcasting using a broadcasting VLAN, in accordance with the detected content distribution conditions. The OLT detects that the number of viewers of a predetermined channel exceeds a predetermined threshold value or is less than the predetermined threshold value, as the content distribution conditions. Further, the OLT performs switching to distribution using a broadcasting VLAN in a case where it is detected that the number of viewers of the predetermined channel exceeds the predetermined threshold value, and performs switching to distribution using an individual VLAN in a case where it is detected that the number of viewers of the predetermined channel is less than the predetermined threshold value.

Abstract: A method for digital resampling in a digital communications receiver is described. The method comprises selecting whole samples of a received input signal in the time domain and implementing sub-sample digital interpolation in the frequency domain. This amounts to performing the time shift of the interpolation process in the frequency domain. The method may be performed in conjunction with the operation of a polarisation recovery filter. A digital communications receiver is also provided the receiver being arranged to perform frequency domain sub-sample interpolation on an input data signal.

Abstract: An apparatus comprising a control circuit providing a variable control signal, and a transmitter. The transmitter operable to provide a modulated optical signal including a plurality of optical subcarriers. One of the plurality of optical subcarriers carries a sequence of modulation symbols. The sequence of modulation symbols includes modulation symbols that are output with a variable transmission frequency in accordance with a transmission probability distribution that is variable based on the control signal.

Abstract: An OSNR spectrum estimation apparatus includes an OSNR estimation unit configured to cause an optical node to estimate an OSNR of a predetermined transmission line using a probe light of a predetermined wavelength in a predetermined number of wavelength channels, the predetermined number being less than the number of all wavelength channels; and an OSNR spectrum calculation unit configured to calculate an OSNR spectrum of all the wavelength channels from OSNRs of the predetermined number of wavelength channels measured by the optical node.

Abstract: A system, method, and apparatus enabling synchronous and asynchronous data sources to be demapped from an oFrame container using a generic mapping system.

Abstract: An optical power supply system includes a power sourcing equipment, a powered device, an information obtaining part and a power supply controller. The power sourcing equipment outputs feed light. The powered device converts the feed light into electric power. The electric power is supplied to a communicator. The information obtaining part obtains communication operation information on an operation status of communication that is performed by the communicator. Based on the obtained communication operation information, the power supply controller controls output of the feed light. The communicator is a wireless communicator that performs wireless communication.

Abstract: An optical line terminal is provided with: an absorption unit that acquires first information of a type and a format that are dependent on a communication scheme and that converts the acquired first information into second information of a type and a format that are common to mutually different communication schemes; and a bandwidth allocation unit that determines bandwidth allocation of an upstream signal allocated to an optical network unit on the basis of the second information.

Abstract: This system and method of for providing a tunable orbital angular momentum system for providing higher order Bessel beams comprising: an acousto-optical deflector configured to receive an input beam, deflect a first portion of the input beam a first deflection angle relative to an axis of propagation and along an optical axis and deflect a second portion of the input beam a second deflection angle relative to the optical axis; a line generator disposed along the optical angle for receiving the first portion and the second portion of the input beam and provide an elliptical Gaussian mean; a log-polar optics assembly disposed along the optical angle for receiving the elliptical Gaussian beam and wrapping the elliptical Gaussian beam with an asymmetric ring; and, a Fourier lens configured to receive the wrapped elliptical Gaussian beam.

Abstract: A downstream bandwidth transmission method for a passive optical network includes: performing a downstream bandwidth allocation (101); sending a result of the downstream bandwidth allocation (102); and sending traffic data based on the result of the downstream bandwidth allocation, where the result of the downstream bandwidth allocation carries optical network unit (ONU) indication information (103).

Abstract: An intelligent subsystem coupled with a system-on-chip (comprising a microprocessor/graphic processor), a radio transceiver, a voice processing module/voice processing algorithm, a foldable display, a near-field communication device, a biometric sensor and an intelligent learning algorithm is disclosed. The intelligent subsystem can respond to a user's interests and/or preferences. Furthermore, the intelligent subsystem is sensor-aware or context-aware.

Abstract: The present disclosure relates to information transmission methods, optical line terminations (OLTs), optical network units (ONUs), and communications systems. One example method on an OLT side includes allocating, by the OLT, an identifier to a first ONU through a first channel, performing, through the first channel, ranging on the first ONU to obtain ranging information about the first channel, and after determining, by the OLT and the ONU through negotiation, to use two channels to perform information transmission, performing, by the OLT, data transmission of a first service with the first ONU through a second channel.

Abstract: According to example embodiments, the OLT includes at least one processor and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the OLT to perform grouping data units for the ONUs in groups, wherein a group includes data units for a subset of the ONUs, encoding the groups of data units into respective sets of at least one codeword, interleaving the at least one codeword of the respective sets thereby obtaining a stream of codewords, and sequentially transmitting the stream of codewords to the ONUs.

Abstract: A receiver module (100) is disclosed for receiving an optical input signal and generating an electrical output signal from the optical input signal. The receiver module comprises an input (110) for receiving an optical input signal and a polarising beam splitter (120) for splitting one of the optical input signal and a local recovery optical signal. The receiver module also comprises a multiport optical coupler (130) for coupling the outputs of the polarisation beam splitter and the other of the optical input signal and local recovery optical signal and outputting a plurality of outputs. The receiver module further comprises a first photodetector unit (140) for individually photodetecting the outputs of the multiport optical coupler and an optical modulation unit (150) for using each of the photodetected outputs to modulate a respective local conversion optical signal, where each local conversion optical signal has a different frequency from the other local conversion optical signals.

Abstract: This application discloses a service signal transmission method and apparatus, and belongs to the field of communications technologies. The method includes: obtaining, by a first network device, N first service signals, where coding types of the N first service signals are the same, and at least two of the N first service signals have different transmission rates, where N?2; inserting padding signals into the N first service signals, to obtain N second service signals, where transmission rates of the N second service signals are integer multiples of a reference rate; and multiplexing the N second service signals into one third service signal, and sending the third service signal to a second network device. In this application, the padding signals are inserted into the N first service signals, to obtain the N second service signals whose transmission rates have an obvious integer-ratio characteristic.

Abstract: An OLT comprises a processor configured to: obtain optical powers associated with ONUs, and generate an instruction instructing a transmit order of transmissions based on the optical powers; a transmitter coupled to the processor and configured to transmit the instruction to the ONUs; and a receiver coupled to the processor and configured to receive the transmissions from the ONUs based on the instruction. An apparatus comprises a receiver configured to receive an instruction instructing a transmit order of transmissions based on optical powers associated with ONUs; a processor coupled to the receiver and configured to process the instruction; and a transmitter coupled to the processor and configured to transmit a transmission based on the instruction.