Abstract: An optical network unit may include a light sensitive unit suitable for receiving NRZ and/or PAM signals effectively. The optical network unit may include a laser transmission unit for providing NRZ and/or PAM signals effectively.

Abstract: The present specification provides a method and a device, the method, performed by a device, for transmitting a first pulse train in a quantum communication system being characterized by: receiving a random access (RA) preamble from another device; transmitting an RA response (RAR) to the other device as a response to the RA preamble; performing a radio resource control (RRC) connection process with the other device; receiving data from the other device; and decoding the data on the basis of key information, wherein a first pulse train is generated in a laser diode of the device, and the key information is determined on the basis that the first pulse train passes through both a first path and a second path and is then transmitted from the device to the other device via a quantum channel.

Abstract: A method of implementing a stretched single optical communication span includes receiving one or more optical signals from an optical fiber span having high loss; adding a pilot signal to the one or more optical signals, subsequent to the receiving; and amplifying the one or more optical signals and the pilot signal with a pre-amplifier that is an Erbium Doped Fiber Amplifier (EDFA). Advantageously, the stretched single span operates below a Hazard 1M environment. A node in a stretched single optical communication span includes an optical multiplexer connected to an optical fiber span having high and a pilot signal, and configured to output a combination of one or more optical signals from the optical fiber span and the pilot signal; and a pre-amplifier that is an EDFA configured to receive the output of the optical multiplexer and provide amplification of the one or more optical signals and the pilot signal.

Abstract: A method is performed by a gateway node that is at a boundary of the first network domain and the second network domain. The method includes receiving an end-to-end delay measurement request sent by the first node to measure end-to-end delay between the first node and the second node. The end-to-end delay measurement request is configured to initiate a first delay measurement process configured for use in the first network domain. The gateway node sends to the second node a delay measurement request configured to initiate a second delay measurement process configured for use in the second network domain. The gateway node determines a delay measurement in the second network domain between the gateway node and the second node using the second delay measurement process. The gateway node sends to the first node an end-to-end delay measurement response that enables the first node to compute the end-to-end delay.

Abstract: A packaged quantum memory device is described. The packaged quantum memory device comprises both quantum memories and quantum memory control devices within an outer package, such that the unit may be shipped, installed, and operated without opening the outer package to tune and/or operate the quantum memories. Optical and electrical control signals may be received from, or provided to, the internal components of the packaged quantum memory device via electrical and/or optical ports located on an outer package layer, and routed to the quantum memories via respective quantum memory control devices. Various electrical, optical, mechanical, and/or spin-related properties of the quantum memories may be tuned using the quantum memory control devices, as well as the local temperature and gas environments around the quantum memories. The packaged quantum memory device may be installed within a cryogenic cooling device, as a unit, and operated via the electrical and optical ports.

Abstract: The present disclosure relates to a fiber network operation apparatus for providing a method of determining a physical path in consideration of network performance and resource efficiency in a space division multiplexing-based fiber network and allocating optical resources according thereto, and an operation method thereof.

Abstract: A burst-mode optical receiver for an optical line terminal (OLT) of a passive optical network (PON) comprises a variable optical attenuator (VOA), a photodiode (PD) which may be a pin-PD or an APD, a transimpedance amplifier (TIA), and a feedback/control circuit for adjusting a bias voltage of the VOA in response to a burst-mode optical input signal level, to provide an attenuated optical output signal to the PD having a narrower dynamic range. Providing signal level adjustment in the optical domain mitigates the requirement for a burst-mode TIA with a large dynamic range and provides for fast switching. The burst-mode optical receiver may comprise a waveguide configuration, wherein a first electro-absorption modulator (EAM) is operable as the VOA and a second EAM is operable as the photodiode. A monolithically integrated electro-photonic circuit comprising the VOA, PD, TIA and feedback/control circuit may be provided using InP-based semiconductor materials.

Abstract: Techniques for detecting an anomaly in a PON include generating an optical profile for the PON based on characteristics of network light level signals, collected over a first time period, delivered over the PON, and generating an optical profile for a customer based on characteristics of customer light level signals, collected over the first time period, delivered over the PON to or from an ONT for the customer. The techniques also include obtaining customer light level signals collected over a second time period, and detecting an anomaly in the PON for the customer in response to determining that the customer light level signals collected over the second time period deviate from the optical profile for the customer or the optical profile for the PON by more than a threshold amount.

Abstract: An object of the present invention is to provide a communication system and a communication method that can suppress an increase in the total fiber distance even if the number of secondary devices increases and that can make complex processing for band allocation for uplink optical signals unnecessary. The configuration of the communication system according to the present invention is a mixture of a ring type and a branch type, in which an optical fiber cable (primary path) from a communication station to each user's home is arranged in a ring (loop) shape, and the primary path is branched and laid to the user's home. Furthermore, unidirectional communication is enabled by a ring-type primary path, and the transmittable amount can be made uniform by further combining time division multiplexing.

Abstract: An optical receiver chip based on OTN transmission technology to solve the high power consumption and serous signal attenuation problems for data transmission below 100 m in the data center includes a receiver, a digital control unit, and a power module. The receiver includes a 28G transimpedance amplifier and a limiting amplifier, converts a weak optical signal into an electrical signal, process a two-stage amplification, and output the signal in a limited state. The signal is then processed by a photodiode into a DC current RSSI, and judged by the internal received signal strength indicator module or the internal optical modulation amplitude loss of signal module of the limiting amplifier. If the signal does not meet the protocol requirements, the output buffer with de-emphasis and the linear equalizer are turned off, and the judgment result is transmitted to the host computer outside the chip simultaneously.

Abstract: An optical phased array (OPA) photonic integrated chip includes a plurality of array elements, a plurality of phase shifters, a plurality of combiners, and an edge coupler configured to couple to a single mode waveguide. The plurality of phase shifters includes a layer of phase shifters that has a phase shifter connected to each array element in the plurality of array elements. The plurality of combiners is configured to connect the plurality of phase shifters to the edge coupler. The plurality of combiners includes a first combiner that has a first output that is connected to a second combiner or the edge coupler, and a second output of the first combiner is connected to a photodetector. An in-phase light portion at the first combiner is output through the first output, and an out-of-phase light portion at the first combiner is output through the second output.

Abstract: The present invention has an object to provide an uplink band allocation apparatus and an uplink band allocation method that are capable of setting an uplink band of a PON in accordance with an application. The uplink band allocation apparatus and method according to the present invention collect not only the amount of the data accumulated in an ONU but also the information of the application (application information) used on a terminal apparatus. Then, the uplink band allocation apparatus and method according to the present invention reflect, on a DBA conducted by the OLT, information of a band and a delay (band delay information) that have been calculated by an application information acquisition server from the application information and that are demanded by the application.

Abstract: A method and system for maintaining an optimized point ahead angle (?a) between an uplink beam (U0) from a first terminal (10) to a second terminal (20), and a downlink beam (D0) from the second terminal (20) to the first terminal (10). While transmitting data via a transmission channel (Tx) from the first terminal (10) to the second terminal (20), a directional variation (??) is applied to an initial point ahead angle (?0) for emitting the uplink beam (U1,U2) along different point ahead angles (?1,?2). A respective intensity (I1,I2) is determined of a part of the uplink beam (U1,U2), received by the second terminal (20), emitted by the first terminal (10) along a respective point ahead angle (?1, ?2). The initial point ahead angle (?0) is adjusted towards an optimized point ahead angle (?a) based on the respective intensity (I1,I2) as function of the different point ahead angles (?1,?2).

Abstract: An apparatus for transmitting real-time video using wavelength division multiplexing. The apparatus may include an input, a transceiver, and processing circuitry. The input may receive at least native video data. The transceiver may transmit transport blocks via an optical transport link defining a plurality of optical channels using wavelength division multiplexing. The processing circuitry may be operatively coupled to the input and transceiver. The processing circuitry may be configured to receive a video frame of native video data from the encoder input and generate a transport block including a video segment of the video frame. The processing circuitry may further be configured to transmit the transport block including the video segment on an optical channel assigned to the apparatus using the transceiver.

Abstract: Infrastructure comprising a wide area network (WAN) is adapted as a transport network portion of a 5G network in which the WAN is sliced at the optical layer on a discrete wavelength basis to provide dedicated network capacity to customers such as service providers, application providers, and network operators. Optical layer slicing extends the slicing construct for a radio access network (RAN) portion of the 5G network through to the WAN to provide end-to-end 5G network slicing from user equipment (UE) accessing an air interface of the network to application servers that are instantiated in data centers in a network cloud portion of the 5G network.

Abstract: An apparatus for facilitating light based communications includes a transceiver, a processing device, and a user interface device. The transceiver includes light emitters and a light receiver. The light emitters emit light. The light receiver is configured for detecting an incoming light signal. The processing device is operatively coupled with the transceiver. The processing device is configured for generating an incoming coded message based on the detecting, decoding the incoming coded message into an incoming message, provisioning the incoming message based on the decoding, obtaining an outgoing message, encoding the outgoing message based on the obtaining of the outgoing message, generating an encoded outgoing message based on the encoding, and generating a command for the transceiver based on the encoding of the encoded outgoing message. Further, at least one of the light emitters is configured for emitting an outgoing light signal based on the command.

Abstract: A PPM-modulated signal is based on a format comprising (i) N data slots per symbol period, (ii) guard slots separating the data slots, and (iii) the symbols are encoded by the position of pulses within the data slots. Timing synchronization of the receiver to an incoming PPM-modulated signal is achieved as follows. The incoming PPM-modulated signal is processed to generate slot detection signals, which are indicative of a presence of a pulse in a corresponding one of the N data slots. A timing correction signal is generated based on a difference between (a) accumulated slot detection signals for receiver data slot 1, and (b) accumulated slot detection signals for receiver data slot N. Timing of the receiver is adjusted based on the timing correction signal.

Abstract: Provided is a communication device that can deliver an improvement in the communication capacity of communication infrastructure with the quality of communication taken into consideration. A communication device includes an acquiring unit configured to acquire quality information of a communication line extending from a first communication device to a second communication device and including an optical communication line, an estimating unit configured to estimate the quality of communication of the second communication device and determine the required quality of communication of the second communication device based on the quality information, and a controlling unit configured to perform control on communication channels in the optical communication line so that the quality of communication satisfies the required quality of communication.

Abstract: Provided is an underwater wireless optical communication system. The system includes an emitting end and a receiving end; where the emitting end includes a beam emitting module and an optical phased array, where the beam emitting module is configured to emit a communication beam obtained by modulating communication information, and the optical phased array is configured to adjust an emission direction of the communication beam; and the receiving end includes a tracking module and an information demodulation module, where the tracking module is configured to receive a target communication beam emitted after adjustment by the optical phased array and align the target communication beam, and the information demodulation module is configured to demodulate the received target communication beam to obtain the communication information.

Abstract: A system (e.g., an optical amplifier) comprising gain fibers (e.g., Bismuth-doped optical fiber) for amplifying optical signals. The optical signals have an operating center wavelength (?0) that is centered between approximately 1260 nanometers (˜1260 nm) and ˜1360 nm (which is in the O-Band). The gain fibers are optically coupled to pump sources, with the number of pump sources being less than or equal to the number of gain fibers. The pump sources are (optionally) shared among the gain fibers, thereby providing more efficient use of resources.