Abstract: Disclosed is a method for monitoring the wavelength of a tunable laser device of user by local OLT. The method is applied to a wavelength division multiplexing passive optical network framework. The framework comprises an ONU, a first athermal array waveguide grating, a transmission optical fiber, a second athermal array waveguide grating and the OLT, which are sequentially connected. ONU comprises tunable wavelength optical transmitters. The method comprises: starting handshaking is carried out between the OLT and the ONU; and the OLT carries out wavelength drifting monitoring during operation of the ONU. Wavelength adjustment can be carried out on the multi-channel tunable laser device in an external auxiliary monitoring environment, thus channel wavelengths of the multi-channel tunable laser device can be accurately controlled, and the requirement for calibration accuracy of channels of the tunable laser device at the ONU is greatly reduced.

Abstract: An information transmission system includes a transmission apparatus and a reception apparatus and uses visible lights as transmission media. The transmission apparatus includes a generating unit and a first replace unit. The generating unit generates a multi-value symbol stream. The first replace unit replaces the multi-value symbol stream generated by the generating unit to a discontinuous symbol stream. The discontinuous symbol stream is a symbol stream without a sequence of identical symbol values. The number of identical symbol values in the sequence is equal to or greater than a predetermined number. The reception apparatus includes an acquiring unit and a second replace unit. The acquiring unit acquires the discontinuous symbol stream. The second replace unit replaces the discontinuous symbol stream acquired by the acquiring unit to the multi-value symbol stream according to a predetermined rule.

Abstract: A distributed antenna system, comprising: master unit configured to: receive MIMO channel signals at MIMO frequency from signal source, MIMO channel signals including first and second MIMO channel signals; generate LO signal; frequency convert first and/or second MIMO channel signal from MIMO frequency to different frequency close to first legacy service frequency band using the LO signal; combine first MIMO channel signal, second MIMO channel signal, and LO signal for transmission; optical link operably coupled with master unit; unit communicatively coupled with master unit via optical link for transceiving first second MIMO channel signal, unit including band processing circuitry configured to process first and second MIMO channel signal; conversion circuitry configured to receive converted MIMO channel signal and to frequency convert converted MIMO channel signal from frequency close to first legacy service frequency band back to MIMO frequency for transmission over antenna.

Abstract: A method, an optical node, and an optical network include a power controller configured to bring channels in-service in parallel over multiple cascaded optical nodes quickly, efficiently, and in a non-service affecting manner. The method, node, and network utilize multiple states of a control loop that maintains a stable response in downstream optical nodes as channels are added in parallel. Further, the power controller is configured to operate independently alleviating dependencies on other power controllers and removing the need for coordination between power controllers. The method, node, and network provide efficient turn up of dense wave division multiplexing (DWDM) services which is critical to optical layer functionality including optical layer restoration.

Abstract: There are provided an optical transceiver, an optical network unit, and an optical transceiver control method that control the operating state of the optical transceiver and reduce the number of terminals of the optical transceiver. An optical transceiver includes: a transmitting and receiving unit that transmits and receives optical signals and that has three or more states for transmission or reception of the optical signals, the states transitioning in sequence; a terminal for receiving a voltage or current as operation instruction information indicating in which one of the states operation is to be performed; and a determining unit for determining one of the states indicated by the operation instruction information, based on a magnitude of the voltage or current received by the terminal. The transmitting and receiving unit operates in the one of the states determined by the determining unit.

Abstract: Methods and systems for optimizing the transmission of superchannels with different modulation formats may include pre-calculating different guardband (GB) values between superchannels and sets of power values for subcarriers to implement subcarrier power pre-emphasis (SPP). When a request for an optical path is received at a network management system, the spectral allocation of each superchannel, including a GB, is determined according to pre-specified rules based on co-propagation of the superchannels with different modulation formats.

Abstract: [Problem] To provide an optical packet buffer control device, without making device construction large in scale, that is capable of dynamically responding to traffic and suppressing power consumption.

Abstract: A network capable of being used in a datacenter is described. The network can comprise a set of optical fiber rings, wherein each optical fiber ring carries data traffic on multiple wavelengths, and wherein each optical fiber ring is partitioned into multiple sectors. In some embodiments, each sector in the multiple sectors can comprise: (1) only one add-wavelength-selective-switch (add-WSS) communicatively coupled to only one optical fiber ring in the set of optical fiber rings, wherein the only one add-WSS is used for sending all data traffic that originates from the sector and is destined to other sectors; (2) an add-electro-optical-switch (add-EOS) communicatively coupled to the add-WSS; (3) a set of drop-wavelength-selective-switches (drop-WSSs) communicatively coupled to the set of optical fiber rings, wherein the set of drop-WSSs are used for receiving data traffic from other sectors; and (4) a drop-electro-optical-switch (drop-EOS) communicatively coupled to a drop-WSS in the set of drop-WSSs.

Abstract: A method and apparatus for performing path protection for rate-adaptive optics is provided. As part of the method, an aggregate input bit stream is received. The aggregate input bit stream is then transmitted using a rate-adaptive optical transceiver when transmitting on a first optical path. When the first optical path has a fault, the aggregate input bit stream is then transmitted on a second optical path using the rate-adaptive optical transceiver and a fixed-rate optical transceiver.

Abstract: A wavelength-selective device includes: a storage in which a wavelength management table is stored; and a processor configured to execute a procedure, the procedure including: searching for one or more paths used as a new path having a first ending time in a network, based on the wavelength management table; selecting a wavelength having a second ending time closest to the first ending time, from one or more wavelengths used on paths found by the searching; and configuring a path using the selected wavelength as the new path.

Abstract: An OLT (1) is formed by N optical transceivers (11), one PON control circuit (12), and one selection and distribution circuit (13). An optical transceiver selection control signal (SC) is transferred from the PON control circuit (12) to the selection and distribution circuit (13). The optical transceiver selection control signal (SC) indicates the timing of a discovery window, the timing of a grant, and a logical link identification number of a registered ONU assigned to the grant (a logical link identification number for a logical link with the registered ONU). The selection and distribution circuit (13) selects one optical transceiver (11-s (s is an integer falling within a range of 0 to N?1)) from the optical transceivers (11-0 to 11-N?1) based on the optical transceiver selection control signal (SC) from the PON control circuit (12).

Abstract: Disclosed is a method for detecting an OTDR curve tail end event to locate an optical fiber break point in an online mode, comprising following steps: 1, an OTDR emits detection light to an optical fiber operation link, and receives reflection light to form reflection sampling point data containing tail end event; 2, head end reflection point in sampling point is found out; 3, traversal is carried out to find search region end point; 4, segmented line fitting is carried out in region of [search region end point, head end reflection point] in reversed direction, start point of section of line meeting predetermined condition is used as a search region start point; 5, if absolute value of difference between largest sampling value in search region and sampling value of search region start point is larger than second preset threshold value, tail end event is judged as reflection tail end event.

Abstract: A drive circuit includes a bias current supply circuit for supplying a bias current to a light-emitting element and a modulated current supply circuit for supplying a modulated current to the light-emitting element, and has a first path through which the bias current flows, a second path including a path for supplying the modulated current to the light-emitting element from the modulated current supply circuit, through which a current returns to the bias current supply circuit through the modulated current supply circuit from the bias current supply circuit without going through the light-emitting element when the bias current flows, and a third path which is joined to the second path in the modulated current supply circuit and has an adjusting resistance before a junction, through which a current flows through the adjusting resistance to the bias current supply circuit when the bias current flows.

Abstract: Methods and systems are provided for wavelength shift elimination during spectral inversion in optical networks. The method includes receiving an input optical signal, and generating a combined optical signal by combining, by Bragg scattering, the input optical signal having an input wavelength with a first pump signal having a first wavelength. The method further includes converting the combined optical signal into an output optical signal, by phase-conjugation, using a second pump signal having a second wavelength. The output optical signal has the same wavelength as the input optical signal.

Abstract: A first photodetector is interconnected with a control unit equipped with a communication interface and powered by a power supply module. An output of a first optical filter is connected to an input of a first photodetector via a second optical filter, while a second output of the second optical filter is connected to an input of a second photodetector. An output of the second photodetector is connected to a control unit. A split branch of a third directional coupler is connected to the input of a third photodetector, the output of which is connected to the control unit. A split branch of a fourth directional coupler is connected to the input of a fourth photodetector, the output of which is connected to the control unit.

Abstract: An apparatus and method for computer network security based on Free-Space Optical Interconnections (FSOI) for board-to-board information transmission. The addition of a controllable, interlocked shutter system creates air-gapped isolation of the boards, allowing for increased obfuscation, and enhanced security.

Abstract: One embodiment provides an apparatus for coupling between a trunk passive optical network (PON) and a leaf PON. The apparatus includes a trunk-side optical transceiver coupled to the trunk PON, a leaf-side optical transceiver coupled to the leaf PON, and an integrated circuit chip that includes an optical network unit (ONU) media access control (MAC) module, an optical line terminal (OLT) MAC module, and an on-chip memory.

Abstract: An optical modulator includes an optical splitter splitting input optical signals into a first optical signal and a second optical signal and transmitting the first optical signal and the second optical signal to a first optical waveguide and a second optical waveguide, respectively, an optical combiner generating an output optical signal by combining the first and second optical signals transmitted from the first and second optical waveguides respectively, and including three output ports including a main output port, a first auxiliary output port, and a second auxiliary output port, three output optical waveguides connected to the three output ports, respectively, and transmitting the output optical signal, and an optical detector connected to at least one of the three output optical waveguides.

Abstract: Adaptive communications focal plane arrays that may be implemented in, e.g., a specially-configured camera that can be utilized to receive and/or process information in the form of optical beams are presented. A specialized focal plane array (FPA) having a plurality of optical detectors is utilized, where one or more optical detectors are suppressed such that data is not allowed to be output from the one or more suppressed optical detectors, and only a significantly smaller number or subset of optical detectors receiving optical beams are allowed to output data. In this way, the rate at which data is to be output by an adaptive communications FPA (ACFPA) can be significantly reduced.

Abstract: A light receiving device that receives a light signal includes: a plurality of avalanche photodiodes, in each of which receiving sensitivity is set in accordance with a bias signal that is provided; a plurality of level conversion units provided in association with the avalanche photodiodes, each of the level conversion units being configured to convert a level of a reference voltage for obtaining the bias signal so as to generate the bias signal and being configured to provide the bias signal to corresponding one of the avalanche photodiodes; and a control unit that generates a first control signal corresponding to a temperature of the light receiving device, and controls a level conversion amount of each of the level conversion units by using the first control signal.