Matches 1 - 50 out of 118 1 2 3 >


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US20140212132 ADAPTIVE EQUALIZER TAP COEFFICIENT CORRECTION METHOD AND OPTICAL RECEIVER  
A method of tap coefficient correction includes: obtaining a synchronization symbol difference between a first polarization and a second polarization orthogonal to the first polarization;...
US20110150498 OPTICAL COMMUNICATIONS WITH POLARIZATION DEPENDENT LOSS COMPENSATION  
The invention related to the system and method for optical communication using light of two polarization states. Polarization distortion loss (PDL) is compensated by implementation of polarization...
US20120063783 SYSTEM AND METHOD FOR REDUCING POLARIZATION DEPENDENT LOSS  
In accordance with the present disclosure a method for reducing polarization dependent loss experienced by an optical signal comprises monitoring a power level of a polarization multiplexed...
US20120263454 Crosstalk-Free High-Dimensional Constellations for Dual-Polarized Nonlinear Fiber-Optic Communications  
A method reduces time-varying polarization crosstalk due to XPolM by transmitting multi-dimensional orthogonal constellations. Three variants of crosstalk-free constellations are provided:...
US20120063781 SYSTEM AND METHOD FOR REDUCING POLARIZATION DEPENDENT LOSS CROSS-TALK EFFECTS  
In accordance with the present disclosure a system for reducing polarization dependent loss (PDL) of an optical signal comprises a delay module coupled to one or more PDL inducing network elements...
US20120189319 ADAPTIVE PMD EQUALIZER AND IMPLEMENTATION  
Polarization mode dispersion (PMD) in a dual-pole optical communications network is compensated for using an adaptive PMD equalizer. The PMD equalizer may include a number of substantially...
US20120002971 POLARIZATION-TRACKING DEVICE HAVING A WAVEGUIDE-GRATING COUPLER  
A polarization-tracking device having a waveguide grating that serves as a polarization splitter and an optical fiber-to-waveguide coupler. The polarization-tracking device also has an optical...
US20140205301 MODULATION UNIT  
A modulation unit for a quantum communication system, wherein said modulation unit comprises an optical component configured to cause a delay between photons with different polarisation modes and...
US20120275797 POLARIZATION SCATTERING COMPENSATION DEVICE AND POLARIZATION SCATTERING COMPENSATION METHOD  
Polarization scattering compensation device and method are disclosed. In the device, a time sequence alignment unit aligns time sequences of signals in the first and second polarization state...
US20140099126 Pair-wise Symbol Correlated High Receiver Sensitivity Modulation Format  
The invention is directed to a novel computer implemented method for finding a modulation format that has better receiver sensitivity than modulation formats that are currently being used, with a...
US20130202314 METHOD FOR TRANSMITTING INFORMATION USING PHOTONS (VARIANTS)  
The invention relates to communications engineering and can be used in the transmission of information remotely on the basis of non-local quantum correlation between quantum particles, some of...
US20110142455 CROSSTALK COEFFICIENT ESTIMATING APPARATUS AND CROSSTALK COEFFICIENT ESTIMATING METHOD  
This invention relates to crosstalk coefficient estimating apparatus and crosstalk coefficient estimating method. The crosstalk coefficient estimating apparatus is used to estimate a crosstalk...
US20130343766 OPTICAL COMMUNICATION SYSTEM AND METHOD  
A method for an optical communication system and an optical communication system comprising a pump source configured to generate a pump signal having rotating polarization, a polarization...
US20070140701 Optical signal polarisation control method and controller device  
A polarisation control method includes the steps of feeding an optical input signal to a first polarisation transformation block for providing a corresponding first optical output signal; feeding...
US20140079408 COEFFICIENT DETERMINING APPARATUS, EQUALIZER, RECEIVER AND TRANSMITTER  
Embodiments of the present invention provide a coefficient determining apparatus, equalizer, receiver and transmitter. The coefficient determining apparatus comprises: a synchronizer configured to...
US20110268456 OPTICAL TRANSMISSION SYSTEM, TRANSMITTER, RECEIVER AND METHOD  
In the optical transmitting system, the optical transmitter transmits a polarization combined signal light obtained by combining a pair of lights having different polarization orientation, and the...
US20100111541 Generation of Quantum-Correlated and/or Polarization Entangled Photon Pairs with Unequal Wavelengths  
The invention provides an apparatus and method for generating quantum-correlated and/or polarization-entangled photon pairs with unequal wavelengths. The photon pairs generated collinearly with...
US20090148170 Skew Compensation Across Polarized Optical Channels  
Embodiments of the present invention provide systems, devices and methods for managing skew within a polarized multi-channel optical transport system. In a DP-QPSK system, skew between polarized...
US20070058982 Surface emitting laser, photodetector and optical communication system using the same  
A surface emitting laser includes a plurality of light-emitting portions for emitting laser light beams in different linearly polarized light directions. The light-emitting portions are formed on...
US20120177372 Apparatus And Method For Generating Interleaved Return-To-Zero (IRZ) Polarization-Division Multiplexed (PDM) Signals  
Return To Zero (RZ) shaping is performed for a first I/Q modulator whose output corresponds to a first polarization component using a first two digital-to-analog convertors (DACs), each of which...
US20100196008 METHODS AND APPARATUS FOR RECOVERING FIRST AND SECOND TRANSMITTED OPTICAL WAVES FROM A POLARIZATION MULTIPLEXED OPTICAL WAVE  
First and second transmitted optical waves having orthogonal polarization states are combined in a polarization multiplexed optical wave. At an optical receiver, an electrical field of the...
US20100329677 Symbol Timing Recovery in Polarization Division Multiplexed Coherent Optical Transmission System  
A method, apparatus and system for providing clock and data recovery in a receiver for receiving a high speed coherent polarization division multiplexed optical signal using a digital signal...
US20100232804 METHODS AND SYSTEMS FOR POLARIZATION MULTIPLEXED MULTILEVEL MODULATION FOR OPTICAL COMMUNICATION  
Multilevel soft-equalizer detectors, such as a maximum a posteriori probability (MAP) detector, suitable for use in polarization multiplexed optical communications using multilevel modulations and...
US20070065156 FIBER-OPTICS MULTIPLEXED INTERFEROMETRIC CURRENT SENSOR  
A fiber-optics multiplexed interferometric current sensor is provided. A broadband light source (BLS) is adapted for providing a light wave, and a depolarizer is coupled to the BLS. A depolarizer...
US20080260393 Transceiver and Method for High-Speed Auto-Compensating Quantum Cryptography  
Provided are an auto-compensating quantum cryptography transceiver and method of transmitting a quantum cryptography key at a high speed. A quantum cryptography transmitter includes a wavelength...
US20120063786 CLOCK RECOVERY WITH CHANNEL COEFFICIENTS  
In a coherent optical receiver of an optical communications network, a method of recovering a clock signal from a high speed optical signal received through an optical link. A set of compensation...
US20140270803 OPTICAL TRANSMISSION USING POLARISATION DIVERSITY  
Method, transmitter, receiver, and system for communicating information carried by a polarization divided optical signal in an optical fiber, comprising: producing and transmitting a polarization...
US20090087191 COLOR SENSORS USING POLARIMETRIC TECHNIQUES  
Embodiments include n apparatus including a color sensor including a transmitter portion and a receiver portion, the transmitter portion including a light source operable to generate and transmit...
US20080085123 Optical switch based on parametric interaction  
A method and apparatus for switching at least one wavelength component of an optical signal beam from a first state to a second state. The phase characterizing the optical signal component is...
US20080124091 Reduction of Signal Degradations in Optical Transmission Links  
Methods, devices and/or systems are provided for reducing signal degradations in optical transmission links. A means for ensuring a flexible manipulation for the improvement of an optical signal,...
US20060013593 Light intensity modulation element, intensity-modulated-light generating device, laser exposure unit and photograph processing apparatus  
Disclosed is a light-intensity modulation element, which comprises a substrate made of a nonlinear optical crystal, and a light waveguide formed in a principal surface of the substrate to extend...
US20140099127 Optical Phase Conjugation Aided Long-Haul Transmission System with Enhanced Signal-to-Noise Ratio and Nonlinear Tolerance  
A long haul transmission system uses a digital signal processor DSP instead of an additional optical phase conjugate copier because the optical phase conjugate copier requires high quality optical...
US20090060524 High frequency signal optical transmission system and high frequency signal optical transmission method  
A filter conducts the round trip by using the return optical signal that has been shifted in frequency, and measures the transmission optical signal and the return signal in phase by the principle...
US20110182572 GENERATION OF A FEEDBACK SIGNAL FOR A POLARIZATION MODE DISPERSION COMPENSATOR IN A COMMUNICATION SYSTEM USING ALTERNATE-POLARIZATION  
The invention relates to a method of generating a feedback signal for adjusting a polarization mode dispersion compensator (PMDC, 21) in a transmission system with alternate-polarization. A first...
US20110293280 Control of an Interferometric Optical Polarization Beam Splitter  
The present invention provides a system, apparatus and method to control an optical polarization beam splitter. A portion of an optical output of the polarization beam splitter is converted into a...
US20070110450 Optical signal regenerator for high bit-rate transmission systems  
A pulsed optical signal regenerator device comprises three optical stages (11,12,13) arranged in cascade between an input (14) to which is applied a signal Si to be regenerated and an output (15)...
US20060159463 Optical waveform measuring apparatus and optical waveform measuring method  
The present invention relates an optical waveform measuring apparatus designed to eliminate the polarization dependency of an intensity correlation signal without a polarization diversity...
US20100196016 Polarization Multiplexing with Different DPSK Modulation Schemes and System Incorporating the Same  
Polarization multiplexing with different differential phase shift keying (DPSK) schemes generally uses DPSK modulated signals modulated using different DPSK modulation schemes and combined with...
US20060045535 Optical transmission system  
To provide an optical transmission system which cancels out noise components and whose construction cost is lower than that of the conventional system, the present invention is an optical...
US20140133865 OPTICAL MODULATION SCHEMES HAVING REDUCED NONLINEAR OPTICAL TRANSMISSION IMPAIRMENTS  
A method of transmitting a data signal using an optical transmitter of an optical communications system. The optical transmitter is configured to modulate an optical carrier in successive...
US20100221018 Polarization mode dispersion suppressing method and polarization mode dispersion suppressing apparatus  
A polarization mode dispersion (PMD) suppressing apparatus wherein a first polarization controller adjusts a polarization of an input signal, thereby generating a first polarization adjusted...
US20120189318 DIGITAL DEMODULATOR ARCHITECTURE  
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...
US20080131138 Optical switch and optical waveform monitoring apparatus  
According to an aspect of an embodiment, an optical switch comprises: a coupler for coupling a signal light and a control pulse;a first nonlinear medium for amplifying the signal light in...
US20080175597 Optical clock signal regeneration device  
An optical clock signal regeneration device, which includes a mode-locking laser element, a signal light provision component and an optical clock signal formation component, is provided. The...
US20070166045 BIREFRINGENT SPECTRAL FILTER WITH WIDE FIELD OF VIEW AND ASSOCIATED COMMUNICATIONS METHOD AND APPARATUS  
A spectral filter is adapted for use in a receiver, for example in a short range submarine laser signal path, wherein the relative orientations of the receiver is such that the signal may appear...
US20060051100 Optical switch and optical waveform monitoring device utilizing optical switch  
The polarization direction of an optical signal is changed by a polarization controller so as to be orthogonal to a main axis of a polarizer. A control pulse generator generates control pulses...
US20100034541 PMDC FEEDBACK SIGNAL FOR ALTERNATE POLARIZATION DPSK SYSTEM  
A feedback signal indicative of the average RF power of an APol-DPSK optical signal is used by a PMD compensator to adjust the amount of compensation applied to the optical signal.
US20140126916 OPTICAL TRANSMISSION SYSTEM, OPTICAL TRANSMITTER, OPTICAL RECEIVER, AND OPTICAL TRANSMISSION METHOD  
An optical transmission system includes an optical transmitter, an optical receiver, and an optical transmission path connecting the optical transmitter and the optical receiver, wherein the...
US20090028555 OPTICAL FILTER  
An apparatus and method are provided for filtering an optical signal by wavelength. An initially polarised signal is passed through a DGD element effective to alter the polarisation state of the...
US20060024064 Method for transmitting data signals and additional signals in an optical network  
The transmission of a data signal (DS) in the form of data packets takes place by means of angular modulation, preferably two or three stage difference phase modulation. The header (HEAD) is...

Matches 1 - 50 out of 118 1 2 3 >