Abstract: An optical add-drop device includes optical circuits. Each of the optical circuits includes first to third sub optical circuits. Each sub optical circuit includes an input coupler, output coupler, and a phase shifter. In each of the optical circuit, two ports of the output coupler in the first sub optical circuit are respectively coupled to the input coupler in the second sub optical circuit and the input coupler in the third sub optical circuit. The output coupler in the second sub optical circuit in each of the optical circuits is coupled to a drop port or the input coupler in the first sub optical circuit in the adjacent optical circuit. The input coupler in the third sub optical circuit in each of the optical circuits is coupled to an add port or the output coupler in the third sub optical circuit in the adjacent optical circuit.

Abstract: Signal sending method and apparatus. The signal sending method includes: sending, by a first apparatus, an optical signal to a second apparatus in a slot before a first wavelength slot; sending, by the first apparatus, a first optical signal to the second apparatus in the first wavelength slot; and sending, by the first apparatus, an optical signal to a second apparatus in the slot after the first wavelength slot. A wavelength of the first optical signal is a first wavelength. The first optical signal sent by the first apparatus in one first wavelength slot is used to carry first wavelength data on one symbol. Wavelengths of the optical signals sent by the first apparatus in the slots before and after the first wavelength slot are wavelengths other than the first wavelength.

Abstract: Apparatus for isolating transmit and receive optical beams having a common wavelength to ensure genderless interoperability in an optical communication system comprises a transmit path that propagates a transmit optical beam at a particular base wavelength and a receive path that propagates a receive optical beam at the same particular base wavelength wherein at least a portion of the receive path is separate from the transmit path. The apparatus further comprises an annular mirror having a receive beam region and a center aperture and the transmit path includes a steering mirror and the receive path also includes the steering mirror. The steering mirror has a single surface that reflects an entirety of the transmit optical beam transmitted along the transmit path and the single surface of the steering mirror reflects an entirety of the receive optical beam received along the receive path. A method of isolating transmit and receive optical beams in an optical communication system is also disclosed.

Abstract: Techniques and circuitry for wavelength monitor and control are disclosed herein. The disclosed wavelength monitor and control circuitry and techniques are designed to realize a multi-channel DWDM optical link by using a photonic receiver that dynamically adjusts resonant wavelengths of the microring drop filter (MDF), as needed. The wavelength monitor and control circuitry can monitor and control the resonant wavelengths of multiple MDFs for a DWDM silicon photonics receiver with minimum power and area overhead. In an embodiment, circuitry for an optical receiver comprises an MDF having resonant wavelength for multiple DWDM channels, and circuitry to control and monitor the resonant wavelength of the MDF in real-time and in manner that compensates for deviation between actual resonant wavelength of the MDF and the incident optical wavelength of the MDF.

Abstract: The present invention provides an optical transmission device, a transmission system, and a control method for a transmission system which make it possible to adjust the wavelength band of dummy light according to the wavelength band of an added main signal. This optical transmission device comprises: an output branching unit which multiplexes and outputs an added main signal and dummy light; a wavelength adjustment unit which adjusts the wavelength band of the dummy light; a signal detection unit to which an optical signal outputted by the output branching unit is inputted, and which detects the wavelength band of the added main signal and outputs a detection result; and a control unit which controls the wavelength adjustment unit according to the detection result from the signal detection unit.

Abstract: A network element configured to operate in an Optical Transport Network (OTN) network includes one or more modules including a first regenerator port and a second regenerator port, wherein the one or more modules are configured to provide a Low Order (LO) regenerator function; and circuitry configured to detect the one or more modules are part of the LO regenerator function, and, responsive to detection of a fault on the first regenerator port, cause forward traffic conditioning at a High Order (HO) path to the second regenerator port. The forward traffic conditioning can include an Alarm Indication Signal (AIS) on the HO path.

Abstract: Signal sending method and apparatus. The signal sending method includes: sending, by a first apparatus, an optical signal to a second apparatus in a slot before a first wavelength slot; sending, by the first apparatus, a first optical signal to the second apparatus in the first wavelength slot; and sending, by the first apparatus, an optical signal to a second apparatus in the slot after the first wavelength slot. A wavelength of the first optical signal is a first wavelength. The first optical signal sent by the first apparatus in one first wavelength slot is used to carry first wavelength data on one symbol. Wavelengths of the optical signals sent by the first apparatus in the slots before and after the first wavelength slot are wavelengths other than the first wavelength.

Abstract: Provided is an optical transmission/reception device (1) for transmitting or receiving an optical signal via a communication path (2) in which a phase change of the optical signal is suppressed. The optical transmission/reception device (1) includes: a transmission device (10) including a framer generation unit (11), a symbol mapping unit (12), and an optical modulation unit (13); and a reception device (20) including an optical reception front end unit (21), an A/D conversion unit (22), a polarization separation unit (23), and a phase estimating unit (24) for estimating a phase of at least one of a plurality of polarizations from a plurality of polarization signals separated by the polarization separation unit (23) and estimating a phase of a remaining polarization on the basis of the estimated phase.

Abstract: An object is to provide an optical modulation/demodulation method, an optical communication system, an optical transmitting device, and an optical receiving device capable of inhibiting an increase in the cost and a decrease in the band at the time of multiplexing services. The optical transmitting device according to the present invention sums a plurality of binary signals that have bit rates having such relation that the bit rate of any higher speed side is twice or more integer multiples of a bit rate of any lower speed side, having smaller amplitude as the corresponding bit rate becomes higher and having matched rise and fall timings, and generates a multi-level signal, and modulates light from one light source. In other words, generating a multi-level signal as a modulation signal enables a plurality of services to be multiplexed by one transmitter.

Abstract: This application provides a data transmission method in an optical network and an optical network device. The method includes: obtaining, by a first device, first synchronization information from a first service data stream, and determining a to-be-transmitted service data stream; generating second synchronization information based on the first synchronization information; mapping the second synchronization information and the to-be-transmitted service data stream to an optical carrier container; and sending the optical carrier container. A second device receives the optical carrier container; obtains a second service data stream and third synchronization information from the optical carrier container through demapping; generates fourth synchronization information based on the third synchronization information; and inserts the fourth synchronization information into the second service data stream, to obtain a third service data stream. In this way, time synchronization precision is improved.

Abstract: The invention relates to a system for managing (1) a communication network (W) of a vehicle, said management system (1) comprising a plurality of computers (10, 20) connected to said network (W), and a two-way wired link (L) connecting said plurality of computers (10, 20), said network (W) having a standby state and an awake state, said plurality of computers (10, 20) comprising a master computer (10) and at least one slave computer (20), said master computer (10) and said at least one slave computer (20) being configured to emit and receive a message relative to a requested state of the network (W) via said two-way wired link (L), the state of at least one of the plurality of computers (10, 20) being controlled from said message relative to the requested state, so as to monitor the state of the network (W), said communication network (W) being a fiber-optic Ethernet network.

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 transceiver can be calibrated using an internal receiver side eye scan generator, and calibration values (e.g., modulator values) can be stored in memory for recalibration of the optical transceiver. The eye scan generator can receive data from the transmitter portion via an integrated and reconfigurable loopback path. At a later time, different calibration values can be accessed in memory and used to recalibrate the optical transceiver or update the calibrated values using the receive-side eye scan generator operating in loopback mode.

Abstract: The optical relay is a C+L-band relay which is inserted between a first transmission path fiber and a second transmission path fiber, and comprises: a first optical fiber amplification unit which is inserted in a first line and amplifies one of a C-band signal or an L-band signal; a second optical fiber amplification unit which is inserted in a second line and amplifies one of the C-band signal or the L-band signal; and an inserting means which inserts some or all of the wavelengths of light output from the first optical fiber amplification unit into the second optical fiber amplification unit, or which inserts some or all of the wavelengths of light output from the second optical fiber amplification unit into the first optical fiber amplification unit.

Abstract: An optical transmission apparatus, includes, a light source configured to output a plurality of light beams having different wavelengths to an optical fiber, a receiver configured to receive, from the optical fiber, a reflected light beam corresponding to each of the wavelengths of the plurality of light beams, and a signal processing circuit configured to estimate a polarization fluctuation portion based on a polarization state of the received reflected light beam corresponding to each of the plurality of wavelengths.

Abstract: A high-bandwidth underwater electrical connector is provided that includes first and second connectors each having free space optical transceivers. The electrical connector further includes self-passivating transition metal contacts that form a non-conductive outer layer when immersed in a fluid. The first and second free space optical transceivers transmit and receive data at high data speeds.

Abstract: Improved systems and methods are provided to implement coherent communication. The system includes an interposer to route the components of an integrated photonic circuit. The interposer provides an interface to couple the components of the integrated photonic circuit including an optical source, modulator, coherent transmitter, coherent receiver, and interconnects therebetween. The optical source can be a grating-coupled surface-emitting laser (GCSEL). The GCSEL splits an optical signal into two symmetrical optical signals that are directed by a waveguide to a coherent transmitter and/or a coherent receiver of the integrated photonic circuit. Coherent communication is maintained and the need for a second laser in the coherent receiver is avoided through the structure of the GCSEL granting dual functional to the optical source.

Abstract: A method and an apparatus for locating a fault cause are provided. The method includes: obtaining parameter values of a plurality of running parameters and a parameter value of a fault parameter in preset duration before a wavelength division multiplexing board device is faulty; determining a correlation between each of the plurality of running parameters and the fault parameter; and determining at least one target parameter from the plurality of running parameters based on a value of the correlation, where a correlation between each of the at least one target parameter and the fault parameter is greater than a correlation between the fault parameter and a running parameter other than the at least one target parameter in the plurality of running parameters. Accuracy of locating a fault cause can be improved in the embodiments of the present disclosure.

Abstract: A method for compensating the distortions introduced by impairments of MZMz implementing an optical transmitter, according to which the level of total amplitude and phase distortions caused by the optical transmitter is measured and all impairments in the constellation domain are compensated by pre-distorting the input signal to be transmitted by symmetrically adding imbalance to the voltage applied to the MZM arms. The imbalance is determined by introducing a phase rotation in either I or in the Q path of the optical transmitter, which compensates the total amplitude distortion, and also introducing a phase rotation to both I and Q paths of the optical transmitter, which compensate the total phase distortion and the phase shift caused by compensating the amplitude distortion, until reaching a desired operating point, which corresponds to the level of pre-distortion.

Abstract: A binary encoder includes an input configured to receive a binary signal, an encoding processor configured to compute a plurality of different variations of the binary signal, combine each of the different variations with a different redundancy sequence to create a plurality of optional output binary sequences, and select one of the optional output binary sequences according to a binary digit prevalence, and an output configured to output the selected binary sequence. A decoder configured to identify a redundancy sequence of a received binary signal to select a transformation function according to the redundancy sequence and to convert the binary signal according to the transformation function.