Abstract: Passive optical couplers having passive optical activity indicators and methods of operating the same are disclosed. An example passive optical coupler for passively coupling first and second optical fibers includes a housing including: a first port configured to receive an end of a first optical fiber, and a second port configured to receive an end of a second optical fiber; and a passive optical activity indicator positioned at least partially within the housing, wherein a first portion of the passive optical activity indicator is exposed through the housing, and wherein the passive optical activity indicator is configured to passively illuminate in response to (i) first light propagating in the first optical fiber when the end of the first optical fiber is received in the first port, and (ii) second light propagating in the second optical fiber when the end of the second optical fiber is received in the second port.

Abstract: An apparatus includes a polarization beam splitter (PBS) and an optical detector. The PBS is configured to receive a polarized optical signal transported via an optical communication path of an optical network. The detector is configured to receive from the PBS a first polarization component of the optical signal, and to produce a first electrical measure of the first polarization component. A processor is configured to determine a dynamic metric of the optical communication path based at least on the first electrical measure. Some embodiments also include a second detector configured to receive from the PBS a second polarization component of the optical signal. The second detector produces a second electrical measure of the second polarization component, and the processor is configured to determine the dynamic metric based on both the first and second electrical measures.

Abstract: A chromatic dispersion measurement method is provided. According to the method, chromatic dispersion sequence processing is performed on acquired frequency domain data to obtain chromatic dispersion sequences of frequency domain data. A correlation operation on the obtained chromatic dispersion sequences is separately performed at a preset interval. A sum of obtained correlation values is calculated to obtain a first value. A chromatic dispersion value is determined according to the first value, a frequency value per unit frequency interval of the frequency domain data and the preset interval. In this way, the chromatic dispersion value can be accurately determined, and the processing efficiency is high.

Abstract: Apparatus and method for acquiring and tracking a data signal are disclosed. Two different CDR circuits are configured to acquire and track data based on two different modulation schemes. While in the acquisition mode, the first CDR circuit may acquire data signal by sampling the signal at a reduced clock rate and handover to the second CDR circuit when a preamble is found. Also in the acquisition mode, the data acquisition and tracking circuit may determine the power level of the preamble signal and dynamically adjust the threshold level for the tracking period upon finding of the preamble.

Abstract: A tracking system includes a tracking arrangement including a processor, memory, and at least a first interface port; and one or more optical modules. Each optical module includes a housing having at least one input port, at least a first output port, and at least a first monitoring port. An optical power splitter arrangement and an optical receiver are disposed within the housing. The splitter arrangement splits optical signals received at the input port onto one or more output lines and one or more monitoring lines. The output lines are routed to the output ports and the monitoring lines are routed to the optical receiver. The optical receiver measures the power of optical signals received from the first monitoring line and provides a measurement signal to the first monitoring port of the housing.

Abstract: A method is provided for monitoring a state of an optical link in a Fiber Channel infrastructure and includes sending an Extended Link Service (ELS) request to read an optical power of the optical link, and diagnosing a degradation of the optical link, based on a response to the ELS request.

Abstract: This invention concerns real-time multi-impairment signal performance monitoring. In particular it concerns an optical device, for instance a monolithic integrated photonics chip, comprising a waveguide having an input region to receive a signal for characterization, and a narrow band CW laser signal. A non-linear waveguide region to mix the two received signals. More than one output region, each equipped with bandpass filters that extract respective discrete frequency bands of the RF spectrum of the mixed signals. And, also comprising (slow) power detectors to output the extracted discrete frequency banded signals.

Abstract: Systems for enhancing the sensitivity of detecting an optical signal using nonlinear optics and method of performing the same. In one embodiment, a single-photon detection system includes an optical amplifier realized in a waveguide, and a photodetector coupled to an output of the optical amplifier. A light detection and ranging system includes the optical amplifier coupled to an optical source and one photodetector. In another embodiment, a photodetection system includes a plurality of optical frequency converters, coupled to an optical source, that sequentially convert a wavelength of photons of the optical source to a final wavelength, and a single-photon photodetector coupled to the optical frequency converters to detect single photons produced by the optical source. In another embodiment, an optical sensor includes an optical pump, and a transducer including an optical ring cavity coupled to the optical pump and configured to utilize optical four-wave mixing to detect an external stimulus.

Abstract: A method of monitoring chromatic dispersion when transmitting an optical signal includes: applying, to an optical signal in which the symbol rate is f, a dip in optical intensity for every n symbols by means of pseudo-RZ modulation where n is an integer equal to or greater than 2, and transmitting the optical signal to which dips have been applied to a transmission path; receiving the optical signal that is transmitted in by the transmission path and detecting the intensity of a frequency component of k*f/n from the received signal where k is an integer equal to or greater than 1; and based on the detected intensity, generating a monitor signal that represents the chromatic dispersion amount.

Abstract: A wavelength dispersion amount estimation method, a wavelength dispersion compensation circuit, and a receiving device which rapidly estimate and set a wavelength dispersion amount to compensate with high accuracy at the receiving device which compensates waveform distortion at an optical fiber transmission path.

Abstract: An apparatus and method for estimating intra-channel nonlinear damage, including: a first determining unit configured to determine a nonlinear phase shift weighting dispersion distribution function of an optical fiber transmission link according to a parameter of the optical fiber transmission link; a segmenting unit configured to segment the nonlinear phase shift weighting dispersion distribution function of the optical fiber transmission link into at least one rectangle; a calculating unit configured to respectively calculate a nonlinear perturbation coefficient of each rectangle in the at least one rectangle, and perform summation on the nonlinear perturbation coefficients of all the rectangles, so as to obtain a nonlinear perturbation coefficient of the optical fiber transmission link; and a second determining unit configured to determine intra-channel nonlinear damage of the optical fiber transmission link according to the nonlinear perturbation coefficient of the optical fiber transmission link.

Abstract: Changes in a signal are detected. The signal is repeatedly sampled in a synchronous manner during a predetermined interval to generate a captured eye diagram. At least one of a positive differential eye diagram or a negative differential eye diagram is generated from the captured eye diagram and a baseline eye diagram. The at least one positive or negative differential eye diagram is analyzed to determine whether a change in signal conditions is present.

Abstract: A chromatic dispersion estimator for estimating a chromatic dispersion in an input signal block comprises a transformer for transforming the input signal block into a transformed signal block in frequency domain, a chromatic dispersion compensator for compensating a certain chromatic dispersion in the transformed signal block to obtain a compensated transformed signal block, an inverse transformer for inversely transforming the compensated transformed signal block into time domain to obtain an output signal, an adaptive filter for filtering the output signal to obtain a filtered signal, and a determiner for determining upon the basis of the filtered signal whether the certain chromatic dispersion corresponds to the chromatic dispersion in the input signal block.

Abstract: A method for determining an optical signal-to-noise ratio penalty as a measure for a quality of an optical signal transmitted via an optical link between a source optical node and a destination optical node in an optical network, the method includes collecting information of the optical link; determining a configuration parameter Pconf of the optical link based on the information of the optical link; adjusting the configuration parameter Pconf to an adjusted configuration parameter P?conf according to linear impairments in the optical link; and determining the optical signal-to-noise ratio penalty based on a non-linear function of the adjusted configuration parameter P?conf, the non-linear function accounting for non-linear impairments in the optical link.

Abstract: The embedded apparatus disclosed herein may measure reflection coefficient values associated with back reflections in a fiber optics transmission system during a variable detection window to detect normal conditions, simulated Brillouin scattering (SBS), or excessive back reflections triggering remedial action. For example, the back reflections may indicate normal conditions if the reflection coefficients measured during an entire detection window remained below a threshold or a maximum reflection coefficient observed therein was below the threshold. Alternatively, the back reflections may trigger remedial action if the reflection coefficients measured in the entire detection window exceeded the threshold or a minimum reflection coefficient observed therein was above the threshold.

Abstract: There is provided a method of determining transmission quality of a path in an optical communication network system obtained by connecting a plurality of networks, the method including: acquiring a value representing transmission performance corresponding to a network condition of each of spans in the path in the optical communication network system; and determining the transmission quality of the path on the basis of the acquired value representing transmission performance corresponding to the network condition of each of spans.

Abstract: In one exemplary embodiment, a method comprises transmitting an optical signal via the optical line, measuring a relative change in spectral intensity of the optical signal near a clock frequency (or half of that frequency) while varying a polarization of the optical signal between a first state of polarization and a second state of polarization, and using the relative change in spectral intensity of the optical signal to determine and correct the DGD of the optical line. Another method comprises splitting an optical signal traveling through the optical line into a first and second portions having a first and second principal states of polarization of the optical line, converting the first and second portions into a first and second electrical signals, delaying the second electrical signal to create a delayed electrical signal that compensates for a DGD of the optical line, and combining the delayed electrical signal with the first electrical signal to produce a fixed output electrical signal.

Abstract: A measurement apparatus includes: a transmitter disposed at a transmission-side node and configured to transmit two pulsed lights with different wavelengths at time intervals to a reception-side node; a transmission controller configured to control the transmitter so as to transmit the two pulsed lights repeatedly while changing the time interval; a receiving unit disposed at the reception-side node and configured to receive the two pulsed lights from the transmitter via one or more relay nodes; a detection unit configured to detect a change in a phase of at least one of the two pulsed lights received by the receiving unit; and a measurement unit configured to measure, based on the time interval and the change in a phase detected by the detection unit, a dispersion value of each transmission line between two nodes of nodes including the transmission-side node, the reception-side node, and the one or more relay nodes.

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: A dispersion measurement apparatus includes: a pulse generator to output optical pulses including an optical pulse with a first wavelength and an optical pulse with a second wavelength to an optical transmission path, the second wavelength being different from the first wavelength; a reception pulse analyzer including an optical receiver that receives the optical pulses output by the pulse generator, and an analyzer that performs a wavelet transform on an electrical pulse output through the reception performed by the optical receiver; and a calculator to detect, based on a result of the wavelet transform, a time difference between the optical pulse with the first wavelength and the optical pulse with the second wavelength, and to determine dispersion in the optical transmission path.

Abstract: A method of monitoring a differential group delay (DGD) of an optical communications signal having a polarisation multiplexed modulation format is described. The method includes the operations of receiving a signal and performing analogue to digital conversion of the signal to generate a digitised signal corresponding to one polarisation of the signal and to generate another digitised signal corresponding to another polarisation of the signal, and applying a polarisation mode dispersion(PMD) compensation to each of the digitised signals. The method further includes the operations of obtaining an indication of the channel transfer function of the optical communications signal, determining a DGD in dependence on the indication of the channel transfer function, determining a delay between the PMD compensated digitised signals, subtracting the delay from the DGD to obtain a corrected DGD, and generating and transmitting a monitoring signal with an indication of the corrected DGD.

Abstract: A transmission-path-type specifying apparatus includes an optical filter that extracts a plurality of different wavelength components from light including wavelength components occurring at the time of communication; an optical switch that simultaneously transmits same pulse signals superposed on light of the extracted wavelength components. The apparatus also includes an ASE modulation controlling unit that obtains a delay-time difference among the transmitted pulse signals when arriving at a destination via a transmission path; a characteristic-value calculating unit that calculates a characteristic value of the transmission path corresponding to a reference time varied depending on the obtained delay-time difference and a type of the transmission path; and a fiber-type determining unit that specifies the type of the transmission path based on the calculated characteristic value.

Abstract: A dispersion measurement apparatus includes: a pulse generator to output optical pulses including an optical pulse with a first wavelength and an optical pulse with a second wavelength to an optical transmission path, the second wavelength being different from the first wavelength; a reception pulse analyzer including an optical receiver that receives the optical pulses output by the pulse generator, and an analyzer that performs a wavelet transform on an electrical pulse output through the reception performed by the optical receiver; and a calculator to detect, based on a result of the wavelet transform, a time difference between the optical pulse with the first wavelength and the optical pulse with the second wavelength, and to determine dispersion in the optical transmission path.

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: A dispersion compensation design system includes a changing unit setting a changed value for the amount of dispersion compensation for a span connecting nodes constituting an optical network; a path classification unit determining whether respective paths in the optical network are capable of transmission with the changed value and classifying one or more of the paths as second category paths based on the determination results; an updating unit updating the amount of dispersion compensation with the changed value if the number of the second category paths in the latest classification result is less than the number of the second category paths in the retained previous classification result; and a repeating unit that, if not all of the paths in the optical network are capable of transmission, prevents use of combinations of amounts of dispersion compensation applied to the spans in the second category paths in the latest classification result.

Abstract: A method of estimating nonlinear transmission impairments of an Optical Channel (OCh) trail in an optical communications network. A per-span nonlinear field variance is calculated for each span of the trail. The per-span nonlinear field variance represents nonlinearly induced noise due to the transmission impairments of that span. The nonlinearly induced noise being imparted to a signal transmitted through the trail and detected by the receiver. A respective covariance between the nonlinear fields contributed by each span pair of the OCh trail is computed. The covariance represents the correlation of the nonlinearly induced noise imparted to the signal within the first span of a span pair with the nonlinearly induced noise imparted to the signal within the second span of the pair. A covariance matrix is populated using the computed per-span variance values and covariance values. A total nonlinear field variance is computed by summing over the covariance matrix elements.

Abstract: Techniques, devices and applications are provided for monitoring a polarization mode dispersion (PMD) effect in an optical signal.

Abstract: A design method includes calculating a calculated compensation amount of a dispersion compensation module arranged on each of a plurality of wavelength paths in such a way that a residual chromatic dispersion value of each of the wavelength paths which transmits an optical signal between an initial node and a final node satisfies a tolerance condition given in accordance with a priority given to each of the wavelength paths; and deciding a decision value to be applied as the compensation amount of the dispersion compensation module based on the calculated compensation amount based on a plurality of candidate values each being prepared in advance as the candidate for the compensation amount of the dispersion compensation module.

Abstract: Methods, systems, and devices are described for a digital demodulator device for processing received optical signals. The device may include a quadrature error filter that receives a digitized version of an optical signal, and removes quadrature errors to generate a filtered series of data samples. The device may also include a frequency offset removal module for performing frequency rotation on the filtered series of data samples. The device may include a chromatic dispersion compensation module which removes chromatic dispersion from horizontal and vertical polarization channels. The device may include a polarization mode dispersion (PMD)/polarization dependent loss (PDL) compensation module which compensates for interference caused by PMD and PDL. The device may also include a phase recovery module configured to track and correct phase.

Abstract: A method and system for measuring chromatic dispersion, experienced by ASK/PSK modulated optical signals, are provided. Dispersion measurement is enabled either by encoding an additional overhead at lower baud rate or by monitoring signal SOP or RF spectrum of signal SOP. The bulk chromatic dispersion of the link is measured by analyzing the dispersion broadening of the overhead constellation or signal temporal diagram, or time-overlapped signal diagram, or overhead spectrum. This information is used to reduce the computation time required for electronic recovery of a highly dispersed signal.

Abstract: Provided is a chromatic dispersion measurement device including a light branching unit that divides a incident measured light signal into a first measured light signal and a second measured light signal and causes a frequency difference between the first measured light signal and the second measured light signal when the signals are output, an optical phase shifter provided in either one of the first branch path and the second branch path having a polarization maintaining characteristic and periodically changing a phase ?i of the measured light signal, an optical combination unit that combines the first measured light signal and the second measured light signal and outputs an interference element of an i-th optical component obtained by interference of the first measured light signal and the second measured light signal when the phase difference is the phase ?i, as a combined measured light signal.

Abstract: The invention relates to a system and method of dispersion measurement in an optical fiber network. The invention provides means for transmitting from a transmitting node, using a single tunable laser transmitter, two consecutive bursts of data at different wavelengths ?1 and ?2 to a receiver node, wherein each burst of data comprises a unique sequence of amplitude modulated data, and wherein the two sequences are injected with a fixed known delay. The delay between the two consecutive bursts of data is maintained by selective switching of the tunable laser, such that clock recovery circuitry at the receiver node remains locked during the delay between the two bursts. The dispersion measurements method of the present invention is based on walk off and bit position detection between two wavelengths suitable for fast optical burst switching network is described. This method does not require an operator, extra equipment, or traffic interruption on the network.

Abstract: Multimode optical fiber systems with adjustable chromatic modal dispersion compensation are disclosed, wherein the system includes a VCSEL light source and primary and secondary optically coupled multimode optical fibers. Because the VCSEL light source has a wavelength spectrum that radially varies, its use with the primary multimode optical fiber creates chromatic modal dispersion that reduces bandwidth. The compensating multimode optical fiber is designed to have a difference in alpha parameter relative to the primary multimode optical fiber of ?0.1?????0.9. This serves to create a modal delay opposite to the chromatic modal dispersion. The compensation is achieved by using a select length of the compensating multimode optical fiber optically coupled to an output end of the primary multimode optical fiber. The compensating multimode optical fiber can be configured to be bend insensitive.

Abstract: Multimode optical fiber systems with adjustable chromatic modal dispersion compensation are disclosed, wherein the system includes a VCSEL light source and primary and secondary optically coupled multimode optical fibers. Because the VCSEL light source has a wavelength spectrum that radially varies, its use with the primary multimode optical fiber creates chromatic modal dispersion that reduces bandwidth. The compensating multimode optical fiber is designed to have a difference in alpha parameter relative to the primary multimode optical fiber of ?0.1?????0.9. This serves to create a modal delay opposite to the chromatic modal dispersion. The compensation is achieved by using a select length of the compensating multimode optical fiber optically coupled to an output end of the primary multimode optical fiber. The compensating multimode optical fiber can be configured to be bend insensitive.

Abstract: A reconfigurable wavelength selective dispersion compensation device RWSDCD for selective compensation of dispersion in optical channels having different wavelengths. The RWSDCD comprises a controllable wavelength selective unit WSU having a plurality of local, wavelength related input/output (I/O) ports. The RWDSD also comprises a dispersion compensation cascade comprising at least one chain of successively connected dispersion compensation units DCUs, wherein one or more of the DCUs in the chain are respectively connectable to one or more of the local I/O ports. The RWSDCD outputs one or more of the incoming optical channels upon selectively compensating chromatic dispersion in them, by controllably passing these channels via one or more DCUs of the dispersion compensation cascade.

Abstract: A wavelength dispersion amount estimation method, a wavelength dispersion compensation circuit, and a receiving device which rapidly estimate and set a wavelength dispersion amount to compensate with high accuracy at the receiving device which compensates waveform distortion at an optical fiber transmission path.

Abstract: A method and system to economically monitor an optical OOK signal that can detect perceptible changes in signal quality and identify the type of optical impairment causing the change. The invention requires a new and novel combination of known techniques to create an eye diagram of the transmitted pulse in a wavelength division multiplexing systems and then removing the noise from the eye diagram. Economy of operation is achieve by using asynchronous sampling techniques for generating the eye diagram. The resulting “cleaner” eye diagram is then analyzed to identify any changes in performance. In the preferred embodiment, the analysis is conducted on histograms generated from eye diagram, the histograms are computed at a number of points across the optical signal pulse period.

Abstract: For example, of a first intensity distribution waveform WF1 indicated by a distance distribution of an intensity of light which returns to one end of a core of a multicore fiber, and a second intensity distribution waveform WF2 indicated by a distance distribution of an intensity of light which returns to the other end of the core, the second intensity distribution waveform WF2 is inverted. Further, for example, an inverted intensity distribution waveform WF3 which is inverted and the first intensity distribution waveform WF1 which is not inverted are added.

Abstract: A wavelength dispersion amount estimation method, a wavelength dispersion compensation circuit, and a receiving device which rapidly estimate and set a wavelength dispersion amount to compensate with high accuracy at the receiving device which compensates waveform distortion at an optical fiber transmission path.

Abstract: An apparatus for monitoring optical signal transmission in a plurality of optical fibers may include a fixture for introducing a bend into the plurality of fibers arranged at respective predetermined locations on the fixture, to cause a portion of light propagating in any of the fibers to scatter out therefrom. The apparatus may include a lens unit positioned to focus the scattered light onto predetermined photo-detectors of an array, in accordance with the fiber from which the scattered light emanates, and generate image data indicating a characteristic of the scattered light detected at respective ones of the photo-detectors identified by location in the array corresponding to the respective ones of the photo-detectors.

Abstract: Methods, systems, and computer program products are provided for measuring modal dispersion in a bi-directional dual-multimode fiber optic network (BDON). A modal dispersion measurement system includes a computer processor that is programmed to receive a first pulse width of a first pulse. The first pulse may be communicated over the BDON that is coupled to the processor. A second pulse width of a second pulse is received, the second pulse width being indicative of the modal dispersion. The second pulse width and the first pulse width are compared by the computer processor to determine a distortion error. A measurement of the modal dispersion is validated in accordance to the distortion error.

Abstract: In an apparatus for supporting designing of an optical network including a plurality of nodes and links which connect the plurality of nodes: a storage stores information indicating distances of the links and information indicating amounts of chromatic dispersion in the links; and a path selection unit selects a path for use in transmission of an optical signal, from among a plurality of paths each extending from a start node to a destination node, by reference to the storage. The path selection unit selects the path for use in transmission on the basis of deviations of amounts of chromatic dispersion accumulated by transmission to respective nodes on each of the plurality of paths, from reference amounts at the respective nodes, and the reference amounts at the respective nodes on each of the plurality of paths are determined according to distances from the start node to the respective nodes.

Abstract: An optical transmission apparatus includes a non-reciprocal device including first to second ports, an optical signal input from the first port being provided to the second port, an optical signal input from the second port being provided to the first port, a dispersion compensator that is coupled to the first port of the non-reciprocal device and that conducts given processing to an optical signal input from the first port of the non-reciprocal device to provide the optical signal subjected to the given processing to the second port of the non-reciprocal device, a first monitor, a second monitor, and a fault determination device that compares a value monitored by the first monitor with a value monitored by the second monitor to determine one of a connection failure, at least at one of the first port, the second port, of the non-reciprocal device and a connection state of the dispersion compensator.

Abstract: A system for estimating cross-phase modulation (XPM) impairments, wherein the method comprises: determining, according to a pump Jones matrix of a pump channel and a probe Jones matrix of a probe channel of each of fiber spans except for the first fiber span in a fiber transmission system, a polarization mode dispersion (PMD)-induced relative polarization status rotation matrix between channels of the each of fiber spans; and determining, according to the rotation matrix of the each of fiber spans, dispersion of a pump signal of the each of fiber spans, differential delay of the pump signal relative to a probe signal of the each of fiber spans and a gain of the each of fiber spans, polarization crosstalk and phase noise of the XPM impairments in the fiber transmission system.

Abstract: A method for monitoring wavelength-division multiplexed (WDM) signal for detecting signal drift of objective signals, including generation of one or more objective signals and a guard signal. The guard signal has a wavelength that is within a range defined by a guard channel. The first and second objective signals and the guard signal are wavelength-division multiplexed to generate a wavelength-division multiplexed signal. The first objective signal, the second objective signal, and the guard signal are assigned to a first multiplexed objective channel, a second multiplexed objective channel, and a multiplexed guard channel, respectively. The wavelength-division multiplexed signal is received by a monitor and then the error rate of the multiplexed guard channel is determined.

Abstract: Described is a method and system for reducing system penalty from polarization mode dispersion. The method includes receiving a plurality of signals at a receiving end of a transmission line, each signal being received on one of a plurality of channels of the transmission line and measuring a signal degradation of at least one of the channels of the transmission line. An amount of adjustment of a polarization controller is determined based on the signal degradation, the amount of adjustment being selected to reduce the polarization mode dispersion. The amount of adjustment is then transmitted to the polarization controller.

Abstract: An apparatus includes a first estimator that estimates a signal quality based on an error correction number of an electrical signal obtained by photoelectrically converting a received optical signal; a second estimator that estimates a signal quality from which the influence of nonlinear effects is removed based on signals upstream and downstream of an identification calculator identifying the electrical signal; and a calculator that calculates the difference between the signal qualities estimated by the first and second estimators to calculate the amount of nonlinear effects.

Abstract: A method of calculating a series of control parameters to be applied to a polarization controller arranged so as to compensate for the modal dispersion of polarization affecting an optical signal passing through an optical link by calculating a plurality of polarization states of which the respective representations on a Poincaré sphere are separated from one another by a distance greater than a minimum distance dependent on an acceptable threshold of bit error ratios and, for each state of polarization thus calculated, associating at least one control parameter to be applied to the polarization controller with the calculated state of polarization.

Abstract: The invention at hand concerns a method and a system for transmitting data in an optical transmission system. A measuring signal is generated having a wavelength which differs from the wavelengths of a data signal that includes the data to be transmitted. The measuring signal is coupled in the optical transmission system, reflected after passing through the transmission path and decoupled again. The coupled measuring signal is compared with the decoupled reflected measuring signal. By taking into account the comparison results, a compensation of the change of the data signal resulting from the dispersion in the fiber is performed in such a way that the data included in the data signal can be used.

Abstract: A system may include a first measurement device configured to be coupled to a first node in an optical path being measured. The first measurement device may be configured to generate a signal at an initiating device; identify an unused channel in an optical path, wherein the optical path includes at least two spans; and transmit the signal on the unused channel. A second test device may be configured to be coupled to a last node in the optical path being measured. The second measurement device may be configured to: receive the signal at a destination device; compensate the signal for chromatic dispersion (CD) and/or polarization mode dispersion (PMD) effects; and determine CD and/or PMD measurements associated with the optical path being measured based on the compensation.