243results about "Polarisation multiplex systems" patented technology

The invention discloses a method of an optical anti-turbulence device for polarization multiplexing spatial optical communication. The mode demultiplexer is connected with the optical fiber; the single-mode optical fiber array is respectively coupled with each spatial intrinsic mode decomposed by the mode demultiplexer; the polarization CBC chip is connected with the other end of the single-mode optical fiber array; the driving control module is connected with the polarization CBC chip; the polarization multiplexing optical communication digital coherent receiver (Rx) is connected with the polarization CBC chip through a single-mode optical fiber; through the arrangement of the polarization CBC chip, the compatibility of a polarization multiplexing technology and a mode multiplexing coherent beam combination technology is realized, the problem of polarization dimension information loss or strong crosstalk caused by the use of a polarization state rotator (PSR) and a polarization maintaining optical fiber in the prior art is solved, modulation information of two orthogonal polarization dimensions is completely reserved, the communication bandwidth is improved, and the communication efficiency is improved. And the communication efficiency is greatly improved.

An electro-optic receiver includes a bus optical waveguide and a plurality of wavelength division multiplexing (WDM) receiver slices positioned along the bus optical waveguide. Each of the plurality of WDM receiver slices includes a WDM element optically coupled to the bus optical waveguide, a photodetector, and a receiver circuit. The photodetector is optically connected to the WDM element by both a first optical connection and a second optical connection. The WDM element conveys a first component of input light through the first optical connection to the photodetector, and a second component of input light through the second optical connection to the photodetector, where first and second components of input light travel in opposite directions through the bus optical waveguide. The receiver circuit generates an electrical data signal from photocurrents received from the photodetector.

Various example embodiments for supporting optical communications in an optical communication system may be configured to support dual-polarization alignment for dual-polarization communications within an optical communication network. Various example embodiments for supporting dual-polarization alignment, within an optical communication network supporting optical communications from a transmitter to a receiver based on dual polarizations including a first polarization and a second polarization, may be configured to support dual-polarization alignment to the dual polarizations at the receiver based on communication of a data segment such that a first portion of the data segment is communicated based on the first polarization and a second portion of the data segment is communicated based on the first polarization and the second polarization.

Systems and methods for increasing throughput of a photonic processor by using photonic degrees of freedom (DOF) are provided. The photonic processor includes a multiplexer configured to multiplex, using at least one photonic DOF, multiple encoded optical signals into a multiplexed optical signal. The photonic processor also includes a detector coupled to an output of an optical path including the multiplexer, the detector being configured to generate a first current based on the multiplexed optical signal or a demultiplexed portion of the multiplexed optical signal. The photonic processor further includes a modulator coupled to and output of the detector, the modulator being configured to generate a second current by modulating the first current.

A dual-polarization (DP) intensity-modulated direct detection (IMDD) receiver includes: an input port configured to receive input light; an optical 2×2 multi-input-multi-output (MIMO) demultiplexer configured to receive light from a first optical transmission path and a second optical transmission path and perform optical 2×2 MIMO polarization demultiplexing; a pair of photodetectors configured to detect outputs at a common carrier frequency; and an electrical 2×2 MIMO demultiplexer configured to receive a signal from the first electrical transmission path and a signal from the second electrical transmission path and perform electrical 2×2 MIMO polarization demultiplexing to output a first demultiplexed signal and a second demultiplexed signal.

The present disclosure describes an optical system and method of operating the optical system. The optical system includes a substrate and first and second photonic integrated circuits. The first photonic integrated circuit is positioned on the substrate. The second photonic integrated circuit is positioned on the first photonic integrated circuit. The second photonic integrated circuit receives a first optical signal that includes a first mode and a second mode. The second photonic integrated circuit includes a polarization splitter rotator, a first demultiplexer, and a second demultiplexer. The polarization splitter rotator separates the first optical signal into a second optical with the first mode and a third optical signal with the first mode. The first and second demultiplexers separate the second and third optical signals into first and second pluralities of optical signals. The first and second pluralities of optical signals couple into the first photonic integrated circuit.

A digital filter (6) performs polarization variation compensation for data of at least two polarizations in which a plurality of known signals are inserted at predetermined positions in each frame by means of a filter in which a tap coefficient is set. Before a frame synchronization unit (4a) generates a frame signal from an output signal of a digital filter, a tap coefficient update circuit (7) updates the tap coefficient such that the difference between the amplitude value of the data and the amplitude value that the data should take is small. After a frame signal is generated, a tap coefficient updating circuit (7) receives the frame signal in a feedback manner, detects a known signal from the data on the basis of the frame signal, and updates the tap coefficient such that the difference between the detected known signal and the true value of the known signal becomes small.

This control signal multiplexer comprises a modulation unit that uses a control signal to polarize and modulate an optical signal for conveying a main signal.

An optical system includes a first modulator configured to: receive first input light, modulate an amplitude of the first input light with a first data signal, modulate a phase of the first input light with a first marker signal, and output to an optical element, as first modulated light, the first input light modulated with the first data signal and the first marker signal. The optical system includes a second modulator configured to: receive second input light, modulate an amplitude of the second input light with a second data signal, modulate a phase of the second input light with a second marker signal, and output to the optical element, as second modulated light, the second input light modulated with the second data signal and the second marker signal. The second marker signal includes a complementary version of the first marker signal.

To select the optimal transmission mode from transmission modes defined by combinations of a plurality of parameters related to transmission performance.SOLUTION: A transmitter-receiver comprises: a transmission mode candidate transmitting unit that transmits transmission mode candidate information including transmission mode information to a transmission device to be communicated; a transmission mode candidate receiving unit that receives the transmission mode candidate information including the transmission mode information of the transmission device to be communicated; a transmission mode selection unit that selects transmission mode information to be used for the communication from the plurality of pieces of common transmission mode information; and a signal transmitting and receiving unit that transmits and receives signals based on the selected transmission mode information. The transmission mode selection unit selects, from the plurality of pieces of common transmission mode information, pieces of candidate transmission mode information to be candidates for transmission capacity required during the transmitting and receiving, and selects, in the selected pieces of transmission mode information, pieces of transmission mode information in which power consumption is reduced or pieces of transmission mode information in which optical frequency utilization efficiency is increased in a descending order of priority.SELECTED DRAWING: Figure 1

To provide an apparatus, method and optical transmitter for monitoring an analog characteristic of an optical transmitter in which: analog characteristic information of the optical transmitter is extracted by using the correlation quantity between the to-be-measured optical signal and the modulated local signal; the required hardware cost is much lower than that of a conventional broadband receiver; and, because there is no need to perform complex digital signal processing (DSP), power consumption is reduced greatly.SOLUTION: The method comprises: inputting a first signal to a first electro-optical converter to obtain a to-be-measured optical signal; inputting a second signal to a second electro-optical converter to obtain a modulated local signal, so that the second signal is determined according to the first signal and a to-be-monitored analog characteristic of the first electro-optical converter; performing correlation processing on the to-be-measured optical signal and the modulated local signal to obtain at least one correlation quantity; and estimating an analog characteristic of the first electro-optical converter according to the correlation quantity.SELECTED DRAWING: Figure 1

A circuit for bidirectional CWDM communication is provided. The circuit includes a polarization splitter rotator, and a first filter. The first filter is configured to demultiplex two or more respective wavelengths from an input signal split by the polarization splitter rotator. The first filter includes a first set of demultiplexer channels, and a first set multiplexer channels, wherein the first set of demultiplexer channels includes a first demultiplexer stage, the first demultiplexer stage including a first number of first component filters, and a second demultiplexer stage including a second number of second component filters having a second passband. The first set of multiplexer channels includes a first multiplexer stage including a third number of third component filters, and a second multiplexer stage including a fourth number of fourth component filters, wherein the third number is less than the first number, and fourth number is less than the second number.

This optical transmission system comprises: a phase conjugate conversion device (200) that performs optical parametric amplification in a first optical parametric amplification unit (238) and in a second optical parametric amplification unit (244), monitors electric power of a first polarized component and a second polarized component of first pilot light, controls the phase of higher harmonic wave excitation light by means of phase shifters (218, 224) so as to maximize the optical power of first pilot light to thereby synchronize the phase of the higher harmonic wave and the first pilot light, and controls a phase shifter (264) disposed in at least one path so as to maximize interference waveforms of respective components of second pilot light, which is different from the first pilot light in terms of the wavelength or the optical power and which has passed through from a pilot light source (270) in a reverse direction, to thereby match the optical length of the path of the first optical parametric amplification unit (238) and the path of the second optical parametric amplification unit (244); and a phase sensitive amplification device (400) for performing phase sensitive amplification on idler light and on an optical signal included in an optical transmission signal through optical parametric amplification using the excitation light controlled by using the first pilot light included in the optical transmission signal.

[Problem] To control according to the requirements of various communication services and transmit information via an appropriate communication network. [Solution] The present invention comprises: a line measurement unit 11 which measures line measurement information when performing line control based on line route information and line parameters for transmitting and receiving communication service data to and from an optical space communication device 2 which performs optical space communication via one or a plurality of lines mounted on a non-terrestrial node group and an optical ground station, on the basis of a service request and line measurement information on a plurality of lines, received from the non-terrestrial node group; a position calculation unit 13 which calculates position information on the non-terrestrial node group; a line parameter calculation unit 10 which calculates line route information and line parameters on the basis of the position information, a service request, and line measurement information; a line control unit 12 which controls a line on the basis of the line route information and the line parameters, for the optical space communication device 2; and a line information communication unit 14 which communicates the service request, the line measurement information, the line route information, and the line parameters with the non-terrestrial node group.

Network elements and methods of use are described herein, including a network element comprising a passive waveguide, one or more modulator, and one or more RF antenna. The one or more modulator is configured to generate first and second channel signals. The first channel signal has first data encoded in a first modulation format. The second channel signal has second data encoded in a second modulation format. The first and second channel signals have first and second carrier frequencies, respectively. The first and second carrier frequencies are in a range between 300 Gigahertz (GHz) and 10 Terahertz (THz). The one or more RF antenna is configured to receive the first and second channel signals and transmit the first and second channel signals into the passive waveguide with first and second polarizations, respectively. The first polarization is different from the second polarization.

In a general aspect, a communication system comprises a first station and a second station. Each station includes a transceiver and a control subsystem. The transceiver includes having one or more photonic crystal masers and one or more photonic crystal receivers. The control subsystem includes one or more lasers optically coupled to the one or more photonic crystal masers and the one or more photonic crystal receivers. The control subsystem also includes modulation electronics in communication with the one or more lasers and configured to control one or more characteristics of a first input optical signal received by each photonic crystal maser. The control subsystem additionally includes demodulation electronics in communication with the one or more lasers and configured to control one or more characteristics of a second input optical signal received by each photonic crystal receiver.

A method for reconstructing a first information stream and a second information stream, the method includes receiving, by an optical receiver, a received multiplexed optical signal that is a transmitted optical signal that passed through a polarization and phase rotating medium, the transmitted multiplexed optical signal being generated by using at least one transmitter phase-modulated periodical pilot signal, and by allocating a first polarization to the first information stream and a second polarization that differs from the first polarization to the second information stream; and processing the received multiplexed optical signal to provide a first reconstructed information stream and a second reconstructed information stream, wherein the processing comprises using at least one receiver phase-modulated periodical pilot signal that is associated with the at least one transmitter phase-modulated periodical pilot signal.

A generator device for generating an arbitrary optical pulse pattern includes:a light source to provide primary laser pulses,a distributor to provide a plurality of primary optical pulses by distributing light of the primary laser pulses (LB00k) into a plurality of branches,a combiner to form an output signal by combining modulated optical signals from the branches, anda controller unit to provide control signals for controlling optical modulators of the branches,wherein a first branch comprises a first optical modulator to form a first modulated optical signal from primary optical pulses of the first branch,wherein a second branch comprises a second optical modulator to form a second modulated optical signal from primary optical pulses of the second branch, andwherein a propagation delay of the second branch is different from a propagation delay of the first branch.

Optical multiplexers, optical demultiplexers, optical transmitters including the optical multiplexers, optical modules including the optical transmitters and the optical demultiplexers, and methods of using the same are disclosed. The optical multiplexers include first and second beam combiners, a polarizing beam combiner, and an optical isolator. The first and second beam combiners each include a reflective surface and at least one filter, and are configured to combine individual optical signals having the same polarization state into a multi-channel polarized optical signal. However, the two separate multi-channel polarized optical signals having different polarization states. The polarizing beam combiner includes one or more reflective surfaces and one or more polarization filters, and is configured to combine the multi-channel polarized optical signals into a multi-channel output signal. The optical demultiplexers are structurally similar to the optical multiplexers, but provide a complementary or reverse function.The present multiplexers and demultiplexers reduce the four-wave mixing effect.

The invention relates to a multi-polarized optical device. The optical device includes a first chip and a second chip. The first chip includes a first polarized signal optical port, a second polarized signal optical port, and one or more optical elements coupled to the first polarized signal optical port and the second polarized signal optical port. The second chip comprises a first polarized signal optical port coupled with the first polarized signal optical port of the first chip, a second polarized signal optical port coupled with the second polarized signal optical port of the first chip, and a multi-polarized signal optical port; and a polarization rotation and combination element coupling the first polarization signal optical port and the second polarization signal optical port with the multi-polarization signal optical port. The first chip includes a first semiconductor chip material. The second chip includes a second semiconductor chip material different from the first semiconductor chip material.

A network or system in which a hub or primary node may communicate with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed to receive data carrying optical signals from, and supply data carrying optical signals to, the hub node. One or more connections may couple each leaf node to the hub node, whereby each connection may include one or more spans or segments of optical fibers, optical amplifiers, optical splitters / combiners, and optical add / drop multiplexer, for example. Optical subcarriers may be transmitted over such connections, each carrying a data stream. The subcarriers may be generated by a combination of a laser and a modulator, such that multiple lasers and modulators are not required, and costs may be reduced. As the bandwidth or capacity requirements of the leaf nodes change, the number of subcarriers, and thus the amount of data provided to each node, may be changed accordingly. Each subcarrier within a dedicated group of subcarriers may carry OAM or control channel information to a corresponding leaf node, and such information may be used by the leaf node to configure the leaf node to have a desired bandwidth or capacity.

This excitation light generation device comprises: a first multi-mode laser that outputs first excitation light; a second multi-mode laser that outputs second excitation light; a first excitation current / temperature controller that controls the temperature and excitation current of the first multi-mode laser; a second excitation current / temperature controller that controls the temperature and excitation current of the second multi-mode laser; a first polarization-maintaining variable optical attenuator that adjusts the intensity of light with the polarized state thereof maintained in linear polarization, and outputs the resulting light; a second polarization-maintaining variable optical attenuator that adjusts the intensity of light with the polarized state thereof maintained in linear polarization, and outputs the resulting light; and a polarization-multiplexing circuit that performs polarization-multiplexing and outputs the result. The first and second excitation current / temperature controllers perform control such that the longitudinal modes of the first excitation light and the second excitation light do not overlap. The first and second polarization-maintaining variable optical attenuators perform control so as to provide equal intensities.　

This signal processing device comprises: a batch adaptive equalization unit that uses a first adaptive filter to subject polarized digital signals obtained via the analog-to-digital conversion of polarized and multiplexed signals to a waveform distortion equalization process; a matrix conversion unit that acquires at least the filter coefficient of the first adaptive filter from batch adaptive equalization unit and converts the acquired filter coefficient by a matrix operation; a degree-of-freedom separation adaptive equalization unit that uses a second adaptive filter including a filter coefficient converted by the matrix conversion unit to subject the polarized digital signals to an equalization process for waveform distortion due to polarization state fluctuation in the transmission path; and a switching control unit that selects a signal subjected to the equalization process by the batch adaptive equalization unit or by the degree-of-freedom separation adaptive equalization unit as a reception signal.　

Provided is a signal processing device including: a batch adaptive equalization unit configured to use a first adaptive filter to perform an equalization process of waveform distortion on each polarized digital signal obtained by performing analog-to-digital conversion on a polarization-multiplexed signal; a matrix conversion unit configured to acquire filter coefficients of the first adaptive filter from at least the batch adaptive equalization unit, and convert acquired the filter coefficients through matrix operation; a degree-of-freedom separation adaptive equalization unit configured to use a second adaptive filter including the filter coefficients converted by the matrix conversion unit to perform an equalization process of waveform distortion due to polarization state fluctuation in a transmission path on each polarized digital signal; and a switching control unit configured to select a signal equalized by the batch adaptive equalization unit or the degree-of-freedom separation adaptive equalization unit as a reception signal.

An optical receiving device includes an optical coherent detecting unit (110) to cause an optical signal in which a plurality of channels is frequency-multiplexed to interfere with single interference light and perform coherent detection, and output an analog signal, an analog signal separating unit (130) to branch the analog signal from the optical coherent detecting unit (110) by the number of branches of N (N is a natural number of 2 or more) in a frequency domain, and output analog signals branched in the frequency domain as analog signals each of which is frequency-converted into a frequency equal to or lower than a set frequency, and an analog-digital converting unit (300) to perform analog-digital conversion on each of the analog signals branched by the analog signal separating unit (130) and converted into a low frequency, and output resultant signals as digital signals.

The present invention makes it possible to accurately compensate for intra-transmitter distortion. A wavelength dispersion compensation filter (31) multiplies each of a real component and an imaginary component of each of a first polarization and a second polarization of a polarization multiplexed optical signal by a filter coefficient for compensating for wavelength dispersion. An adaptive equalizer (32) multiplies an input signal and its phase conjugation by a complex impulse response and adds together signals multiplied by the complex impulse response. The adaptive equalizer (32): applies, to each polarization, a phase rotation for carrier phase compensation including a frequency offset and the inverse rotation of the phase rotation; and adds together, for each polarization, a signal to which the phase rotation is applied and a signal to which the inverse rotation of the phase rotation is applied.

Transparent optical repeater for satellite, and communication satellite including such a repeater. This transparent optical repeater, configured for onboard use on a satellite, comprises: - an optical fiber (OF) assembly; - a first optical head (OHU1); - a first low-noise optical amplifier (LNOA); - a polarization splitter and controller (PCS) comprising, for each output channel of the bandpass filter (BPF), a channel polarization splitter and controller (C-PCS); - a third high-power optical amplifier (HPOA), per output channel of the polarization splitter and controller (PCS); - a polarization combination unit (PBC), configured to recombine the respective output channels of the two optical multiplexers (HPWDM); and - a second optical head (OHU2) configured to output the optical signals from the output of the polarization combination unit (PBC). Figure for the abstract: [Fig. 4]

To provide a multi-stage optical MIMO demultiplexer.SOLUTION: An optical polarization demultiplexer 200 is formed by: a polarization splitter and rotator (PBSR) 202; two 50 / 50 couplers 204 and 206; and two phase shifters 208 and 210. The two phase shifters 208 and 210 are controlled by another control signals Φ1212 and Φ2214. Each of the two phase shifters 208 and 210 is a differential phase shifter. The phase shifter 208 is mounted as an interferometer having two individual phase shift elements 208a and 208b that adjust an optical phase to one direction with one arm of an interferometer, and adjust an optical phase to an opposite direction with the other arm. The phase shifter 210 also has the same structure.SELECTED DRAWING: Figure 2

An optical receiver (100) includes: a polarization controller (102) arranged to receive a first modulated optical signal having a first polarization and an unmodulated optical carrier signal polarized and aligned with the first modulated optical signal as its input, the first modulated optical signal having a negligible spectral power density within a predetermined bandwidth BW around the spectrum of the unmodulated optical carrier signal; an optical filter device (104) having a primary polarization mode; and a coherent optical receiver device (106), wherein the polarization controller is arranged to apply a polarization rotation to the first modulated optical signal and the unmodulated optical carrier signal such that their polarizations are aligned with the primary polarization mode of the optical filter device, the optical filter device is arranged to receive and separate the unmodulated optical carrier signal from the first modulated optical signal, and the coherent optical receiver device is arranged to receive the separated signal and use the unmodulated optical carrier signal as a local oscillator (LO) signal to perform coherent detection of the first modulated optical signal.