Abstract: A redundant network system includes a compute node having a network interface card includes a node port. The redundant network system includes a primary switch having a primary switch component and a primary switch port coupled to the primary switch component. The redundant network system includes a secondary switch having a secondary switch component and a secondary switch port coupled to the secondary switch component. The redundant network system includes a cable assembly having a node connector coupled to the node port, a primary connector coupled to the primary switch port, and a secondary connector coupled to the secondary switch port. The cable assembly includes a signal splitting circuit between the node connector and the primary and secondary connectors. The cable assembly includes a first cable between the signal splitting circuit and the primary connector and a second cable between the signal splitting circuit and the secondary connector.

Abstract: Configurations for an optical system with phase shifting elements are disclosed. The optical system may include a first waveguide that provides light to a second waveguide, which may be a slab waveguide. A phase shifting element may be disposed on the slab waveguide and may be heated to induce a temperature change in the slab waveguide. By increasing the temperature of the propagation region of the slab waveguide, the index of refraction of the propagation region of the slab waveguide may shift, thus causing the index of refraction of light propagating through the propagation region to shift, thus shifting the phase of the light. This may result in an optical component capable of phase shifting light for reducing coherent noise while being energy efficient and maintaining a small form factor.

Abstract: Modules for optical time-domain reflectometry (OTDR) are connected via at least one fiber link of a fiber optic communication network. The modules can perform OTDR operations on the at least one fiber link. In addition, the modules can establish an inter-node communication channel between each other on the at least one fiber link. The channel allows the OTDR modules to synchronize their OTDR operations and to exchange information, such as OTDR traces, between each other.

Abstract: An optical network device includes a receiver that receives a polarization multiplexed optical signal and a processor. The processor separates an electric field information signal indicating the polarization multiplexed optical signal into first and second polarization components orthogonal to each other, generates third and fourth polarization components by controlling the first and second polarization components, calculates an evaluation value corresponding to a power of the third or fourth polarization component for each of a plurality of positions on a transmission line, calculates a variation in the evaluation value for a control amount for each of the plurality of positions, and decides whether a first position is a position to be detected based on a result of comparing a variation in an evaluation value for the first position with a variation in an evaluation value for a second position adjacent to the first position.

Abstract: A basic insulating plug and an electric system. The basic insulating plug includes an insulating housing, a first conductor, a first RFID tag and insulating filler. The first conductor includes a first end arranged in the insulating housing. The first RFID tag is located at an end surface of the first end or on a lateral side of the first conductor. The first RFID includes a temperature sensor configured to measure a temperature of the first conductor, an integrated circuit coupled to the temperature sensor and configured to receive a signal indicative of the temperature from the temperature sensor, and an antenna coupled to the IC and configured to transmit temperature data based on the signal and receive electric power for powering the RFID tag. The insulating filler is adapted to fix the first RFID to the first conductor by filling a void between the first conductor and an internal surface of the insulating housing.

Abstract: An interconnect transceiver for transmitting and receiving optical signals, comprising an electronics module with a transceiver engine, and a photonics module with a laser source, a modulator, a photodetector to monitor the laser, one to receive an external optical signal, and a controller to operate the laser source and the laser source modulator, an electronic switch having two states is proposed. The first state is to allow monitoring of the modulated laser source by the transceiver engine, so as to acquire a reference set of operating parameters, and the second state is where a signal from the modulated laser source is directed to the controller, such as to allow real-time control of the source of the transmitting laser and modulator by the controller.

Abstract: A system for optically aligning a photonics die to a fiber array, the fiber array comprising a first and a second fiber channels, the system comprising: the photonics die having: a first and a second optical channels; a first and a second wavelength division multiplexing (WDM) couplers each comprising a bar port, a cross port, and a common port, the first and the second WDM couplers being optically connected to the first and the second optical channels, respectively, via the bar ports and the common ports; and a waveguide crossing optically connecting the cross ports of the first and the second WDM couplers; the system being adapted to couple an optical signal received from the first fiber channel into the cross port of the first WDM coupler and into the waveguide crossing, the optical signal being propagated from the waveguide crossing into the cross port of the second WDM coupler.

Abstract: A customer premises device including an optical modem including at least one upstream laser is power controlled to provide one or more reduced power levels of service in response to a detected AC input power failure, and/or in response to control commands, e.g., from an optical line terminal (OLT). The commands control the customer premises device to switch to a reduced power consumption mode of operation. During the reduced power mode one or a few lasers are powered, e.g., on an intermittent but predictable basis. During normal operation mode each of the upstream lasers are powered. One or more receiver circuits are also powered off during reduced power mode operation in some embodiments. A schedule is used in some embodiments to control when one or more upstream lasers and/or receivers are powered. In some embodiments the schedule is determined based on information provided by the OLT.

Abstract: Aspects relate to a photonic processing system, an integrated circuit, and a method of operating an integrated circuit to control components to modulate optical signals. A photonic processing system, comprising: a photonic integrated circuit comprising: a first electrically-controllable photonic component electrically coupling an input pin to a first output pin; and a second electrically-controllable photonic component electrically coupling the input pin to a second output pin.

Abstract: A terminal node, an optical network and/or a method are described in which a first processor of a first optical protection switching module having a first optical switch, and a second processor of a second optical protection switching module having a second optical switch coordinate switching of the first optical switch and the second optical switch upon detection of a first failure by the first processor, or the detection of a second failure by the second processor. The first processor monitors optical signals received by a first line port to determine a first failure in a first working path at a first layer (e.g., physical layer) within an optical communication model. The second processor monitors the optical signals received by another line port to determine a second failure in the first working path at a second layer (e.g., optical layer) within the optical communication model.

Abstract: Systems, methods, and non-transitory computer readable media are configured to determine data for subcarriers of a cable modem signal. Values which characterize the cable modem signal can be generated. A plot can then be generated. The plot can depict one or more of the values which characterize the cable modem signal.

Abstract: The present invention relates to technical field of communications and provides a method and a device for site selection for a monitoring station. The method comprises acquiring a site list comprising multiple relay stations and a connection relationship of optical cables among the relay stations; sequentially setting each relay station to be a starting site, and traversing the relay stations in the site list according to a preset coverage range from the starting site, and determining a set of uncovered relay stations corresponding to each starting site; according to a preset intersection base, traversing the set of relay stations that cannot be covered corresponding to each starting site to get an intersection, and determining one or more relay stations corresponding to a set of whose intersection result is empty as a target monitoring station. The method improves efficiency and accuracy of site selections and has wide applicability.

Abstract: In some embodiments, a system includes a super-channel multiplexer (SCM) and an optical cross connect (OXC) switch. The SCM is configured to multiplex a set of optical signals into a super-channel optical signal with a wavelength band. The OXC switch is configured to be operatively coupled to the SCM and a reconfigurable optical add-drop multiplexer (ROADM) degree. The OXC switch is configured to be located between the SCM and the ROADM degree and the OXC switch, the SCM, and the ROADM degree are configured to be included in a colorless, directionless, and contentionless (CDC) optical network. The OXC switch is configured to switch, based on the wavelength band, the super-channel optical signal to an output port from a set of output ports of the OXC switch. The OXC switch is configured to transmit the super-channel optical signal from the output port to the ROADM degree.

Abstract: Disclosed embodiments include a small form-factor pluggable (SFP) optical transceiver having optical time domain reflectometer functionality. A monitor processor is included in the transceiver to report link status and failure information to a cloud-based monitoring application. When a fiber optic link is established, the monitor processor remains idle to reduce power consumption by the transceiver. Upon failure of the link, the monitor processor sends a failure report to the monitoring application which can use the data to alert operators to presence and location of optical fiber breaks in the network.

Abstract: A wavelength-setting auxiliary device according to an embodiment of the inventive concept includes an optical wavelength analyzer configured to transmit a test signal having a first wavelength to an optical line terminal, and to execute a central wavelength detection algorithm based on a result of detecting power of a return signal for the test signal to set optical wavelength information of a tunable optical module, and a connector connected to the tunable optical module for interfacing data transmitted between the optical wavelength analyzer and the tunable optical module.

Abstract: In a configuration wherein N individual fibers interconnect two devices, each fiber can be configured, through configuration of the packet processing devices at each end of the fiber, to carry traffic in a single direction. From the perspective of the first device, an arbitrary subset T of the N fibers can be used for transmitting signals to the second device. The packet processing devices terminating a subset R of the remaining N-T fibers can be configured so that the first device may receive signals from the second device.

Abstract: According to examples, a wavelength identification and analysis sensor may include a wavelength transmitter, operably connectable to an input or output of a wavelength selective device of a wavelength division multiplex (WDM) network, to transmit test signals on a plurality of wavelengths into the input or output of the wavelength selective device of the WDM network. A wavelength analyzer is to detect returned signals from the input or output of the wavelength selective device of the WDM network, with each returned signal being associated with one of the transmitted test signals. Further, the wavelength analyzer is to analyze the returned signals and identify, based on the analysis of the returned signals, a wavelength associated with the input or output of the wavelength selective device of the WDM network.

Abstract: A polarimeter system integrated into an optical line system includes a transmitter coupled to a transmit filter communicatively coupled to an output port in an optical line device, wherein the transmitter is configured to generate a polarization probe signal, and wherein a wavelength of the polarization probe signal is configured to operate in-service with traffic-bearing channels on the output port; and a polarimeter receiver coupled to a receive filter communicatively coupled to an input port in the optical line device, wherein the polarimeter receiver is configured to vary arrangement of input light from the filter and to measure various outputs of the varied arrangement to derive measurement of State of Polarization (SOP) of the input light.

Abstract: A method of stimulating a MicroElectroMechanical Systems (MEMS) structure (e.g. a cantilever), and an optical sensor for use in such a method, using optical radiation pressure instead of electrostatic pressure, or the like. An optical pulse creates optical radiation pressure which stimulates movement of the MEMS structure and then movement of the MEMS structure may be measures. An interrogating light may be input after the optical pulse to measure movement of the MEMS structure. Advantageously, the same light source can be utilized to stimulate movement of the MEMS structure and to measure movement of the MEMS structure.

Abstract: The present invention provide an optical distribution method that includes determining, a first optical distribution frame and a second optical distribution frame, and generating first port indication information and second port indication information according to fiber patch cord setting information; and sending the first port indication information to the first optical distribution frame, sending the second port indication information to the second optical distribution frame, receiving a first port identity and a fiber patch cord identity corresponding to the first port identity which are sent by the first optical distribution frame, and receiving a second port identity and a fiber patch cord identity corresponding to the second port identity which are sent by the second optical distribution frame.

Abstract: Dynamic restoration involves routing and bandwidth assignment of an unplanned restoration path in a wavelength switched optical network (20), having regeneration nodes (60), nodes each having a ROADM (62) having drop paths and add paths. An electrical switch (68) provides configurable regeneration capacity by coupling selected drop paths to selected add paths. Some of the configurable regeneration capacity is kept for unplanned restoration paths. A PCE determines (120) routing and bandwidth assignments for an unplanned restoration path for the traffic flow to avoid a fault, and sends (130) configuration messages to the nodes to set up the unplanned restoration path dynamically and to configure the electrical switch to provide regeneration on the path. Keeping some reconfigurable regeneration capacity enables much longer unplanned paths to be found to avoid faults, and enables wavelength conversion if needed. Thus the reliability of finding at least one path avoiding the fault can be increased.

Abstract: Provided are a silica-on-silicon-based hybrid integrated optoelectronic chip and a manufacturing method therefor. The hybrid integrated optoelectronic chip comprises a silicon substrate (1), wherein the surface of the silicon substrate (1) is provided with a platform (8), lug bosses (6,7) and a groove (10); a silica waveguide element (2) is arranged in the groove (10), the lug bosses (6,7) are protruded from the surface of the platform (8), and the surface of the platform (8) is provided with a discontinuous metal electrode layer (3); and the surface of the metal electrode layer (3) is provided with solder bumps (4), and an active optoelectronic chip (5) is arranged above the solder bumps (4) and the lug bosses (6, 7).

Abstract: Embodiments of the present invention provide a wireless communication method, base station and system. The base station includes several LED lights and/or several VLC/IR receivers. The several LED lights are configured to send downlink signals in an OFDMA standard to a user terminal, and the several VLC/IR receivers are configured to receive uplink signals that are of an SC-FDMA standard and sent by the user terminal. The base station further includes a baseband signal processing unit configured to equate the several LED lights and/or the several VLC/IR receivers with radio remote units of an LTE mode to perform processing and resource management. The embodiments of the present invention are capable of reusing baseband signal processing and resource management manners in an existing LTE system, thereby simplifying resource management and baseband signal processing operations performed by the base station, and saving the base station resources.

Abstract: In an optical transmission system including at least one ring network configured by plural nodes, each node of the ring network is provided with the optical switch having connection configuration that the output in at least two directions of a signal input to the node is allowed and the output of the optical switch functions as input to another node included in the plural nodes.

Abstract: The dynamic range of an optical link in a network is determined by simultaneously transmitting signals from two network elements at first and second frequencies, which create a combined signal at a third frequency. The transmission power levels of selected network elements is successively increased until the measured power from the third frequency no longer changes in a predictable manner, at which point the upper limit of the dynamic range of the optical link is determined.

Abstract: An apparatus and method for fault indication and localization in a Passive Optical Network (PON) comprising a multistage power splitter (100, 200, 300) with at least one 1:N splitter (120, 221, 222, 321, 322) followed by N items of 2:M splitters (131, 132, 231-233, 331-336), wherein N and M are integers greater than 1. The apparatus also comprises an Optical Time Domain Reflectometry (OTDR) device (110, 210, 310) capable of inserting an OTDR signal into the power splitter (100, 200, 300), and adapted to insert the OTDR signal between the first stage of the at least one 1:N splitter (120, 221, 222, 321, 322) and the second N items of 2:M splitters (131, 132, 231-233, 331-336).

Abstract: The disclosure provides a method and a system for detecting a fiber fault in a Passive Optical Network (PON). The system comprises an optical path detection device, a Wavelength Division Multiplexing (WDM) coupler, a wavelength selection coupler, a branch fiber selector and a wavelength selection router. The detection system is attached to an original PON system, without influencing the operation of the original system while performing the detection. With the disclosure, the problem of being unable to determine whether there is a fault in a branch fiber due to the loss of an optical path detection reflection signal is solved, the branch fiber with a fault can be quickly located and fixed, thus the operational and maintenance costs of an operator are reduced.

Abstract: The present invention relates to the field of network communications and discloses a method for calculating a nonlinear transmission impairment, including: determining that no pump channel exists in an optical fiber link, obtaining a factor of intra-band nonlinear noise that does not pass through an optical filter, and obtaining integral power in signal light bandwidth of a span; correcting the factor of intra-band nonlinear noise that does not pass through an optical filter, to obtain a factor of intra-band nonlinear noise of the span that passes through an optical filter; calculating nonlinear noise of the span; and obtaining total nonlinear noise of the optical fiber link according to the nonlinear noise of the span, and obtaining a nonlinear transmission impairment of the optical fiber link. Embodiments of the present invention further provide an apparatus for calculating a nonlinear transmission impairment of an optical fiber link.

Abstract: The invention discloses a system, a method and an apparatus for optical network protection. The system includes: an output control apparatus for obtaining protection mode information configured by a system and controlling an input signal to be output from a set line corresponding to said protection mode information; and a detection control apparatus for detecting powers of signals transmitted on an active line and on a standby line, if it is determined that the active line is abnormal and the standby line is normal according to detection results, then controlling the input signal to be output from a protection line corresponding to the protection mode information; if it is determined that the active line is normal, or that the active line and the standby line are abnormal according to the detection result, then controlling the input signal to be output from a set line corresponding to the protection mode information.

Abstract: An optical transmission system for optically transmitting information between apparatuses via an optical transmission path. The system includes: a sending unit that emits, to the optical transmission path, excitation light for detecting an inter-apparatus connection via the path; a responding unit that receives the excitation light from the path and emits detection light to the path using light energy of the excitation light; a response receiving unit that receives the detection light from the path and outputs a detection light current; a detecting unit that detects presence/absence of the inter-apparatus connection based on the detection light current; a light signal transmitting unit that emits, to the path, a light signal for optically transmitting the information based on the detection result by the detecting unit; and a light signal receiving unit that receives the light signal from the path.

Abstract: A bidirectional monitor module includes a 2×2 optical coupler configured to output input light that is input from a first port to a second port and drop the input light input from the first port to a third port and also output input light that is input from the second port to the first port and drop the input light input from the second port to a fourth port; an optical output unit configured to output one of light that is dropped and output from the third port and light that is dropped and output from the fourth port; and a monitor unit configured to monitor optical power of the light output from the optical output unit.

Abstract: A method, an apparatus and a system for detecting a connection status of an optical fiber jumper are provided in the embodiments of the present invention. The method for detecting a connection status of an optical fiber jumper includes: judging a connection status of a second port and a first port according to whether an optical signal sent by the first port to the second port through a first optical fiber is received, wherein the first optical fiber is connected to two ends of an optical fiber jumper, and the two ends of the optical fiber jumper are connected to the first port and the second port respectively; and obtaining a port identification corresponding to the first port according to the optical signal if the optical signal is received.

Abstract: Novel tools and techniques that can be used to detect network impairment, including but not limited to impairment of optical fiber networks. In an aspect, such tools and techniques can be deployed at relatively low cost, allowing pervasive deployment throughout a network. In another aspect, such tools and techniques can take advantage of a “dying gasp,” in which a network element detects a sudden drop in received optical (or electrical) power, resolution, etc. at short time scales and sends a notification across the network before the connection is completely compromised. In yet another aspect, some tools can include a supervisory function to analyze aspects of the dying gasp with the goal to determine network segments associated with an impairment and an estimate of the location of an impairment within the network.

Abstract: Node equipment 1, having optical attenuator unit 21 for optically attenuating wavelength division multiplexing signals received and optical multiplexer/demultiplexer unit 5 for performing optical multiplexing/demultiplexing of the wavelength division multiplexing signals received from the optical attenuator unit 21 via an optical cord 11, includes: output level detecting unit 24 for detecting the optical power level of the wavelength division multiplexing signals at a pre-stage of the optical cord 11; input level detecting unit 52 for detecting the optical power level of the wavelength division multiplexing signals at a post-stage of the optical cord 11; deciding unit 25 for deciding abnormality of the optical power level loss through the optical cord 11 from the optical power levels detected by the output level detecting unit 24 and input level detecting unit 52; and control unit 26 for controlling the optical attenuation of the optical attenuator unit 21 according to the abnormality decision result by the d

Abstract: In a first aspect, the method and apparatus of the present disclosure can be used to periodically and/or intermittently place one or more ONUs attached to a PON in a power savings mode so that an OTDR test can be performed. While in the power savings mode, the ONUs temporarily suspend their transmitter function and power down their upstream lasers. In a second aspect, the method and apparatus of the present disclosure can be used to coordinate the performance of OTDR during one or more periodic or intermittent discovery slots used to detect and register ONUs recently connected to the PON. Because new ONUs are infrequently connected to the PON and ONUs already registered are not permitted to transmit during the discovery windows, OTDR can be performed during these windows without impacting, to a great degree, the normal operation of the PON.

Abstract: A system and method is disclosed that allows for the monitoring, analyzing and reporting on performance, availability and quality of optical network paths. The correlation of PM parameter metrics to client connections, coupled with threshold-based alarm generation provides a proactive and predictive management, reporting and analyzing of the health and effectiveness of individual path connections to alert Operational Support (OS) staff and/or customers to signal degradation and impending Network Element (NE) failures. The system and method performs in real-time processing intervals required for alarm surveillance in a telecommunications network.

Abstract: An apparatus and method for deriving fiber characteristics between two nodes in an optical communication network are disclosed. A roundtrip time for a signal to travel between two nodes is measured by sending the signal via the optical supervisory channel from a first node to a second node, which is configured for loopback operation. Fiber characteristics can be calculated based on the measured roundtrip time.

Abstract: A communication light detecting structure includes a communication optical fiber configured to transmit communication light; a leakage optical fiber optically connected to the middle of the communication optical fiber via optical connection portions, the leakage optical fiber being different in core refractive index from the communication optical fiber; and a light detecting unit configured to detect part of the communication light leaking from the optical connection portions as leakage light. A communication light detecting optical connector includes the communication light detecting structure. A communication light detecting optical cable includes the communication light detecting structure. The communication optical fiber and the leakage optical fiber may have the same core diameter. The communication optical fiber and the leakage optical fiber may have the same cladding refractive index.

Abstract: A laser source is configured for all-optical AM-FM up-conversion. In one exemplary embodiment, an amplitude modulated (AM) optical input signal containing a baseband signal at a sub-microwave frequency, is injected into the laser source. The amplitude of the AM optical input signal and the optical carrier frequency are adjusted so as to place the laser source in a period-one dynamical state characterized by a transitioning of the laser source from a free-running optical frequency to at least two optical frequencies having a separation distance equal to a period-one microwave frequency. As a result of the period-one dynamical state, a frequency modulated (FM) optical output signal containing the baseband signal carried at the period-one microwave frequency, is propagated out of the laser source. The period-one microwave frequency is operative as a sub-carrier signal.

Abstract: A fiber fuse detecting apparatus provides early detection of a fiber fuse generation in an optical fiber that propagates laser light, preventing the damage from expanding. It comprises light input means arranged on a laser light incidence side of the optical fiber that inputs at least a portion of reverse direction propagation light propagating in a reverse direction to light incidenting the optical fiber, light receiving means that photo-electrically converts light input by the light input means, electric filter means that extracts from an output signal of the light receiving means a prescribed frequency band component that contains a periodic signal due to fiber fuse, detecting means that detects change of or a prescribed value in output level of the electric filter means, and warning means that emits a warning signal in response to a detection output of the detecting means. The laser light to the optical fiber is stopped or reduced by means of the warning means.

Abstract: A method includes generating a test signal and modulating the test signal. The method may also include transmitting the test signal on an optical path, where the optical path may include a number of add-drop multiplexer devices and amplifiers. The method may also include receiving the test signal at a destination device and converting the received test signal into an electrical signal. The method may further include identifying a portion of the electrical signal that is associated with the modulated test signal.

Abstract: Mechanisms for operating a network element in an optical network are disclosed. A network element has a plurality of ports, each port including a respective receive input for receiving an optical signal from another network element and a respective transmit output for transmitting an optical signal to the other network element. Each port is configured with a respective fault detection mode of a plurality of fault detection modes.

Abstract: A method for allocating faults in a passive optical network (PON) by placing a number of passive unique optical correlators in a number of respective diagnostic points of the PON, each of the passive unique optical correlators being responsive to an optical diagnostic signal by returning a predetermined unique matching signal; by further transmitting the diagnostic optical signal in the PON towards the diagnostic points to receive upstream response signals from the correlators. Upon detecting presence or absence, in the received response signals, of a predetermined unique matching signal expected from a specific optical correlator, judging about a fault in proximity of the respective specific diagnostic point.

Abstract: A biological optical measurement instrument has a gain adjustment unit (40) configured to set the gain value according to the intensity of the passing light in the measurement data detected by the optical measurement unit (12), a gain storage unit (44) configured to store the damage gain value set by the gain adjustment unit (40) when a damaged incident optical fiber (6a) or a damaged detection optical fiber (8a) is used, a gain comparison unit (42) configured to compare the gain value set by the gain adjustment unit (40) and the damage gain value stored in the gain storage unit (44), and a damage determination unit (46) configured to determine whether or not the incident optical fiber (6a) or the detection optical fiber (8a) is damaged on the basis of the comparison result by the gain comparison unit (42). The display unit (36) displays the damage condition.

Abstract: For an apparatus which communicates data of a number of virtual lanes over a number of physical lanes, where the number of virtual lanes is different than the number of physical lanes and where a mapping between the virtual lanes and the physical lanes is not fixed, a method is provided for ascertaining the mapping between the virtual lanes and the physical lanes. The method includes: applying an impairment to a communication capability of one of the physical lanes so as to increase bit errors for data communicated via said one physical lane; determining a test bit error rate for each of the plurality of virtual lanes while the impairment is applied to the communication capability of the one physical lane; and ascertaining from the test bit error rates which of the virtual lanes is/are mapped to the one physical lane whose communication capability was impaired.

Abstract: In general, the present invention provides novel approaches to signal propagation modeling that utilize the following: 1) geographic segmentation is applied by separating a large fiber optic network into individual non-overlapping segments, defined by optical add/drop placements; 2) impairment segmentation is applied, such that optical noise, self-phase, cross-phase, four-wave mixing, and other impairments are all treated separately; 3) each impairment is calculated by the most efficient approach to achieve the minimum required accuracy, the approaches being fully numeric, semi-analytic, or empirical; 4) impairment concatenation rules are applied to compute an overall impairment experienced by a signal that traverses more than one segment; and 5) impairment scaling rules are applied to rapidly estimate changes in configuration that can lead to improved performance (i.e. higher capacity, longer distance, or lower cost).

Abstract: The invention refers to a optical communication network comprising a monitoring node having a port for outputting at least one optical signal that has a first wavelength range over an optical link of the network to a reflector node of the network. In order to allow for efficient monitoring the optical link it is suggested that the reflector node comprises a wavelength selective optical reflector connected to the link, the reflector being configured for generating a monitoring signal by reflecting a part of the optical signal back into the link, the monitoring signal having a second wavelength range that is a proper sub-range of the first wavelength range and the monitoring node comprises a detector coupled with the port for determining whether the link is defective arranged for detecting the monitoring signal generated by the reflector node.

Abstract: A method includes applying pulsed light to a first end of an optical fiber from an optical fault locator during a first distance test. The method includes determining an estimated distance to a fault based on the pulsed light. The method includes sending information indicative of the estimated distance to a remote device. The method also includes applying first visible light from the optical fault locator to the first end of the optical fiber to facilitate identification of the fault at a first site that is remote from the first end of the optical fiber.

Abstract: The invention relates to a system for the certification of a passive optical network and for the detection of problems and faults in the last fibre legs, which is suitable for use in passive optical networks which, between the OLT device housed in a telephone central office and the user device of ONT, includes optical dividers or splitters which, in the downward direction, distribute the optical signal to all of the users within a tree-and-branch architecture, and in the upward direction, combine the optical signals from all of the ONTs. The system is based on the incorporation of a group of devices known as an OLT emulator and a remote testing unit which are joined to the corresponding wall socket of the telephone central office and user, such that the remote testing unit is positioned facing an OLT in operation, allowing the certification of the last leg of the optical network and the detection of problems and faults in a PON network in operation.

Abstract: An apparatus comprising an optical transmitter, a coarse tuner coupled to the optical transmitter and having a first tuning range, a fine tuner coupled to the optical transmitter and having a second tuning range smaller than and within the first tuning range, a wavelength division demultiplexer coupled to the optical transmitter and to a plurality of optical fibers, and a detector coupled to the optical transmitter and the wavelength division demultiplexer.