| Class / Patent application number | Description | Number of patent applications / Date published |
|---|
| 398159000 | Reducing distortion or dispersion | 28 |
| 20090190933 | DISPERSION AND NONLINEAR COMPENSATOR FOR OPTICAL DELIVERY FIBER - A system for dispersion compensation in a terahertz system includes an optical fiber configured to transmit an optical pulse, a compensator optically coupled to the optical fiber, the compensator configured to compensate for a dispersion of the optical pulse caused as the optical pulse propagates through the optical fiber, and an optically induced terahertz device optically coupled to the compensator, whereby the optically induced terahertz device is configured to transmit or receive terahertz radiation. | 07-30-2009 |
| 20100266291 | System and Method for Coherent Detection of Optical Signals - An optical communication system ( | 10-21-2010 |
| 20110318019 | COMMUNICATION TRANSMISSION SYSTEM WITH OPTICALLY AIDED DIGITAL SIGNAL PROCESSING DISPERSION COMPENSATION - The present disclosure is directed to managing dispersion compensation in optical transmission line utilizing single mode fiber with no in-line dispersion compensation. A communication system terminal includes one or more dispersion compensation modules configured to compensate for at least a portion of optical dispersion associated with optical data signals supplied from the transmission line. A receiver communicatively coupled to the transmission line includes a digital signal processor configured to compensate for an additional portion of dispersion associated with the optical data signals converted to electrical signals by the receiver. | 12-29-2011 |
| 20100329695 | DISPERSION SLOPE COMPENSATION AND DISPERSION MAP MANAGEMENT SYSTEMS AND METHODS - The present disclosure relates to dispersion slope compensation and dispersion map management systems and methods in an optical network utilizing a reconfigurable optical add-drop multiplexer (ROADM) with a plurality of different values of dispersion compensation modules (DCMs). The DCMs form a dispersion compensation ladder at certain intermediate nodes in the optical network to provide dispersion slope compensation and dispersion map management. The reconfigurable routing structure of the ROADM enables these intermediate nodes to route individual wavelengths to any one of the DCMs as required for the particular path of the wavelength. Advantageously, the present invention removes the requirement for banded compensation at receiver nodes and allows for dispersion map management at intermediate points along a fiber route as opposed to bulk compensation at the receiver. | 12-30-2010 |
| 20100028020 | Multimode Optical Fibers - A multimode optical fiber has an equivalent modal dispersion value (DMD | 02-04-2010 |
| 20100098434 | METHOD FOR DETERMINING VALUE OF CHROMATIC DISPERSION COMPENSATION - A method for determining a value of chromatic dispersion compensation in an optical network including a plurality of nodes connected by at least one transmission line, the plurality of nodes including a plurality of dispersion compensators, the optical network including a plurality of wavelength paths between the optional nodes, the method includes determining a compensation value of the dispersion compensators in the optical network by the computer, the compensation value selecting that an error between the object value of the residual chromatic dispersion in accordance with of the first end node of the first path and the permissible value of the residual chromatic dispersion of the first end node of the first path is least, and the value of the residual chromatic dispersion of the first end is in the permissible value of the residual chromatic dispersion of the second end node of the second path. | 04-22-2010 |
| 20090202255 | ABSTRACT OPTICAL RECEIVER WITH AUTOMATIC DISTORTION CANCELLATION - An optical receiver includes closed-loop composite second order (CSO) distortion correction logic. An optical communication system includes a transmitter comprising open-loop composite second order (CSO) distortion correction logic, and a receiver comprising closed-loop composite second order (CSO) distortion correction logic. | 08-13-2009 |
| 20110206382 | METHOD AND A SYSTEM WITH DISTORTION COMPENSATION - The invention relates to a method and an apparatus for distortion compensation of signals transmitted via a bidirectional link between a client device and a host device, said method comprising the steps of performing a post-distortion-compensation for an upstream signal received by the host device on said bidirectional link by adjusting post-compensation parameters of a post-compensation unit of said host device and transforming the adjusted post-compensation parameters into pre-compensation parameters of a pre-compensation unit of said host device which performs a pre-distortion compensation for a downstream signal transmitted by said host device via said bidirectional link to said client device. | 08-25-2011 |
| 20090080902 | DISPERSION COMPENSATION CONTROLLING APPARATUS AND METHOD FOR SEARCHING FOR AMOUNT OF DISPERSION CONTROL - In order to enhance dispersion control, the apparatus includes a dispersion controller; a quality index generator generating a quality index representing a quality of an optical signal output from the dispersion controller; and a searching unit searching for an amount of dispersion control applying to the dispersion controller which amount optimizes the quality index, wherein the searching unit includes a splitting-half searching unit roughly searching, in a splitting half method, a range in which dispersion is controllable by the dispersion controller for an amount of dispersion control such that the quality index generated by the quality index generator becomes preferable, and a sweep searching unit thoroughly searching, by sweeping, a limited range based on the amount of dispersion searched by the splitting-half searching unit for an amount of dispersion control that optimizes the quality index generated by the quality index generator. | 03-26-2009 |
| 20090097860 | Optical Dispersion Compensation - A method of providing dispersion compensation includes providing a dispersion signal indicative of an amount of dispersion for at least one channel of a multi-channel optical signal. A dispersion compensator is controlled in accordance with the dispersion signal to optically compensate for the dispersion of the optical signal. | 04-16-2009 |
| 20080260394 | Method and apparatus for dispersion mitigation in optical links - An optical communications system includes an optical transmitter that generates a modulated optical signal at an output. The modulated optical signal propagates through an optical link where the dispersion of the optical link is imprinted onto an optical spectrum of the modulated optical signal. A demodulator receives the modulated optical signal and filters at least a portion of the optical spectrum with the imprinted dispersion of the optical link, thereby mitigating effects of dispersion in the modulated optical signal and generating a demodulated optical signal at an output. An optical detector generates an electrical data signal from the demodulated optical signal. | 10-23-2008 |
| 20090245809 | Optical transmission system - An optical transmission system capable of efficiently reducing waveform distortion of an optical signal. A transmitting-side distortion compensation coefficient storage of a transmitting station stores transmitting-side distortion compensation coefficients for compensating for waveform distortion of an optical signal to be transmitted to a receiving station. A transmit signal processor performs distortion compensation on the optical signal on the basis of a suitable transmitting-side distortion compensation coefficient stored in the transmitting-side distortion compensation coefficient storage. A transmitter transmits the distortion-compensated signal to a transmission path. A receiver of the receiving station receives the optical signal from the transmission path. A receiving-side distortion compensation coefficient storage stores receiving-side distortion compensation coefficients for compensating for waveform distortion of the optical signal received by the receiver. A received signal processor performs distortion compensation on the received optical signal on the basis of a suitable receiving-side distortion compensation coefficient. | 10-01-2009 |
| 20100014873 | Adaptive non-linearity compensation in coherent receiver - The invention relates to optical communication, in particular to compensation of non-linear distortions incurred in high bit-rate optical communication systems. A method and system for compensating self-phase modulation at an optical receiver of an optical transmission system using polarization division multiplexing and a modulation scheme with constant amplitude is proposed. The method comprises the step of performing a phase modulation on a received signal, wherein the received signal comprises two signal components associated with two orthogonal polarizations, each component comprising an in-phase sub-component and a quadrature-phase sub-component, thereby spanning a four-dimensional space. The phase modulation is determined by evaluating an error signal which depends on the distance in the four-dimensional space between the received signal after the phase modulation and a four-dimensional sphere defined by target constellation points of the optical transmission system. | 01-21-2010 |
| 20080226302 | CHROMATIC DISPERSION COMPENSATION SYSTEM AND METHOD - Dispersion compensation is provided in an optical transmission system. An optical line couples first and second transceivers, and a plurality of amplifiers coupled to the optical line are spaced throughout the optical line with variable span distances. A plurality of dispersion compensation modules include a coarse granularity fiber, a connector, and a fine granularity fiber. A memory is associated with the dispersion compensators to provide information related to the value of the dispersion compensation. | 09-18-2008 |
| 20080226303 | DISPERSION-MANAGED OPTICAL TRANSMISSION SYSTEM - An optical transmission system that alleviates waveform distortions due to nonlinear effects in fibers. A transmitter sends WDM signals to a receiver over a dispersion-managed optical transmission line with in-line optical repeaters. The transmission line is divided into a plurality of dispersion compensation intervals each composed of a main segment and a compensation segment. Chromatic dispersion is managed such that the dispersion compensation intervals have a non-zero net dispersion at every boundary point between them, or such that the number of zero-dispersion boundary points is reduced. The main segment is a series of repeater sections with negative dispersion, while the compensation segment is a single repeater section with positive dispersion. Non-uniform distribution of net chromatic dispersions over the transmission length is achieved by combining repeater section with different average dispersions, dispersion compensation intervals with different numbers of repeater sections, or repeater sections with different span lengths. | 09-18-2008 |
| 20100316392 | TUNABLE DISPERSION COMPENSATION APPARATUS, OPTICAL RECEPTION MODULE AND METHOD - An apparatus includes: a first dispersion compensator that is arranged on an optical path between an input port and an output port, that has a dispersion compensation band, and that substantially compensates a chromatic dispersion to signal light by using a variable amount of dispersion compensation, a second dispersion compensator that is arranged on the optical path, that has a dispersion compensation band different from the dispersion compensation band of the first dispersion compensator, and that substantially compensates the chromatic dispersion to the signal light by using a variable amount of dispersion compensation and a controller that controls the first dispersion compensator in accordance with the value of chromatic dispersion to be compensated and that controls the amount of dispersion compensation and the dispersion compensation band in the second dispersion compensator in association with the amount of dispersion compensation in the first dispersion compensator. | 12-16-2010 |
| 20110249979 | TUNABLE DISPERSION COMPENSATOR CONFIGURED FOR CONTINUOUS SETPOINT CONTROL - A tunable dispersion compensator (TDC) is tuned from a first dispersion setpoint to a second dispersion setpoint while maintaining continuity of the dispersion. The dispersion tuning follows a pre-determined trajectory in the time domain, so that continuity of the optical dispersion across the channel optical bandwidth is maintained while minimizing all other TDC-induced optical impairments during a tuning period | 10-13-2011 |
| 20090324247 | OPTICAL MODULATOR - The present invention relates to an optical modulator that generates quaternary amplitude modulated light without inter-symbol-interference by splitting input light into three optical paths, generating a continuous wave signal in a first optical path, generating binary phase modulated lights using a single drive MZ type optical phase modulator in second and third optical paths, and interfering them at in-phase and at field amplitude 1:a:b. | 12-31-2009 |
| 20100329694 | ELECTRICAL DOMAIN SUPPRESSION OF LINEAR CROSSTALK IN OPTICAL COMMUNICATION SYSTEMS - The present disclosure provides electrical domain suppression of linear crosstalk in optical communication systems using single-carrier implementations. This electrical domain suppression applies spectral shaping in the electronic radio frequency (RF) domain. Advantageously, spectral shaping in the electronic RF domain transfers system complexity from the bulk optical domain into the highly integrated CMOS (or equivalent) domain. The spectral shaping can include electronic circuitry including an electrical filtering block and a signal linearization block prior to optical modulation. The electrical filtering block suppresses coherent interference terms and can include an RF-domain low pass filter. The signal linearization block linearizes modulator response to compensate spectral regrowth due to nonlinear mixing in the modulator. | 12-30-2010 |
| 20100158537 | PROPAGATION APPARATUS AND DISPERSION VALUE SETTING METHOD - A propagation apparatus includes a plurality of dispersion compensation execution units which accept a signal of a single wavelength from a wavelength-multiplexed signal which is received and execute dispersion compensation on the signal by inputting the accepted signal to a tunable dispersion compensator with an adjusted dispersion value, and a dispersion value calculation unit which acquires each dispersion value adjusted by the plurality of the dispersion compensation execution units, approximates the dispersion value of the wavelength assigned to a newly built line by using the acquired dispersion values whose signal error rates are in a tolerable range, and sets the approximated dispersion value as an initial value in the tunable dispersion compensator of the newly built line. | 06-24-2010 |
| 20100142973 | SEMICONDUCTOR LASER WITH LOW RELATIVE INTENSITY NOISE OF INDIVIDUAL LONGITUDINAL MODES AND OPTICAL TRANSMISSION SYSTEM INCORPORATING THE LASER - A semiconductor laser comprises an electrically isolated active section and at least one noise reducing section and operates on a ground state transition of a quantum dot array having inhomogeneous broadening greater than 10 nm. The laser preferably emits more than 10 optical modes such that a total relative intensity noise of each optical mode is less than 0.2% in the 0.001 GHz to 10 GHz range. The spectral power density is preferably higher than 2 mW/nm. An optical transmission system and a method of operating a quantum dot laser with low relative intensity noise of each optical mode are also disclosed. | 06-10-2010 |
| 20100196017 | DISTORTION COMPENSATING APPARATUS, OPTICAL RECEIVING APPARATUS, AND OPTICAL TRANSMITTING AND RECEIVING SYSTEM - A distortion compensating apparatus which compensates for distortion in a waveform of a received light signal through a digital signal processing includes a plurality of fixed amount compensators which compensate for the distortion in the waveform at respective given compensating amounts. The combination of operating states of the plurality of fixed amount compensators is changed by on/off switching of each of the plurality of fixed amount compensators, and the plurality of fixed amount compensators are cascaded. | 08-05-2010 |
| 20100092181 | LOW CONVERSION RATE DIGITAL DISPERSION COMPENSATION - A method of suppressing effects of aliasing in a system for digitally processing a high speed signal having a symbol rate of 1/T. The high speed signal is sampled at a fractional multiple (N) of the symbol rate, wherein 1| 04-15-2010 | |
| 20100046961 | DISTORTION COMPENSATOR, OPTICAL RECEIVER, DISTORTION COMPENSATOR AND OPTICAL RECEIVER CONTROLLING METHODS, AND OPTICAL TRANSMISSION SYSTEM - A distortion compensator, an optical receiver and a transmission system including an operation selectively compensating for linear waveform distortion exerted on an optical signal via a plurality of distortion compensators and compensating for nonlinear waveform distortion exerted on the optical signal using nonlinear distortion compensators. | 02-25-2010 |
| 20120263479 | OPTICAL NETWORK COMMUNICATION SYSTEM WITH VARIABLE OPTICAL ATTENUATION AND METHOD OF OPERATION THEREOF - A method of operation of an optical network communication system includes: coupling an input fiber; receiving light with a lens from the input fiber, the light having a predetermined amount of mode-field-diameter dispersion; tilting a mirror for reflecting the light after the light is transmitted through the lens; and positioning an output fiber for retransmitting the light from the lens after the light is reflected from the mirror for wavelength-dependent-loss reduction. | 10-18-2012 |
| 20120269519 | Apparatus and Method to Calculate a Noise Figure of an Optical Amplifier for Wavelength Channels in a Partial-Fill Scenario to Account for Channel Loading - An apparatus comprising a processor configured to calculate a noise figure of an optical amplifier for a plurality of selected wavelength channels in a partial-fill scenario that accounts for channel loading. The noise figure is calculated using a plurality of corresponding noise figure correction values at a plurality of wavelengths based on an effective number of channels. | 10-25-2012 |
| 20120281988 | Optical Transmission System - In an optical multilevel transmitter ( | 11-08-2012 |
| 20110311233 | AUTOMATED DISPERSION COMPENSATION OVER A BROAD WAVELENGTH RANGE FOR COHERENT OPTICAL PULSES - The present application is directed to an apparatus and method for the automated compensation of dispersion over a broad wavelength range for coherent optical pulses. In one embodiment, the present application discloses an automatic dispersion compensating optical apparatus configured to change chirp introduced into an optical signal by an optical system in optical communication with the dispersion compensating optical apparatus and includes at least one wavelength-tunable source of coherent optical pulses configured to output at least one optical signal, at least one dispersion compensation device configured to receive the optical signal from the coherent source, and at least one controller in communication with the dispersion compensation device and configured to adjust chirp introduced into the optical signal by the dispersion compensation device as the wavelength of the optical signal is varied. | 12-22-2011 |
