31results about "Polarisation multiplex systems" patented technology

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]

A self-homodyne detection coherent transceiver includes a first analog adaptive polarization controller (APC) configured to split the remotely sent local oscillator signal into two portions, including a first remotely sent local oscillator signal and a second remotely sent local oscillator signal; a second analog APC configured to split a polarization multiplexed signal into a first data signal and a second data signal; an analog adaptive phase rotator (APR) coupled to an output of the first analog APC, the analog APR configured to control respective phases of the first remotely sent local oscillator signal and the second remotely sent local oscillator signal for carrier phase error compensation; and a 4-level pulse amplitude modulation (PAM4) digital signal processor (DSP) chip coupled to outputs of a coherent receiver, which includes the first analog APC, the second analog APC, and the analog APR followed by a coherent receiver circuit.

We provide a transmissive optical repeater. [Solution] The transmissive optical repeater of the present disclosure is configured to be incorporated into a satellite and comprises a set of optical fibers (FO), a first optical head (OHU1), a low-noise optical amplifier (LNOA), a polarization separation controller (PCS) having a channel polarization separation controller (C-PCS) for each output channel of an optical bandpass filter (BPF), a high-power optical amplifier (HPOA) for each output channel of the polarization separation controller (PCS), a quadrature polarization coupler (PBC) configured to recombine the two output channels of each of two high-power optical multiplexers (HPWDM), and a second optical head (OHU2) configured to transmit the output optical signal of the quadrature polarization coupler (PBC).

In optical interconnect systems, information may be encoded in different wavelengths of light in an optical signal in a wavelength division multiplexing (WDM) scheme. The inventors have recognized and appreciated that the data rate of an optical interconnect system may be doubled by employing a polarization multiplexing scheme, where some information is encoded in an optical signal having a first polarization state and other information is encoded in an optical signal having a second, orthogonal polarization state as the different polarizations will act independently while propagating along a fiber. Accordingly, described herein are systems and techniques for optical interconnect systems employing polarization multiplexing.

The present invention provides a transmitter, receiver, quantum key distribution system, and method that can suppress the decrease in frequency utilization efficiency. [Solution] The transmitter comprises a first light source that outputs a first light, a first branching unit that splits the first light into a first polarized light with a first polarization and a second polarized light with a second polarization, a first modulation unit that modulates the first polarized light based on a first random number, a second modulation unit that modulates the second polarized light based on data for bit position synchronization of the first random number, and a first polarization multiplexing unit that polarization multiplexes the modulated first polarized light and the modulated second polarized light and transmits the polarization multiplexed first polarization multiplexed light to a receiver.

An optical input / output chip and distributed computing system, including: output sub-chip includes first light processing module to form N first light branches output from laser source, divide and modulate each first light branch into M first light sub-branches according to M wavelengths, form second optical branches containing N different modes from N modulated first optical branches before being output in first polarization state; input sub-chip includes second optical processing module, to form N third optical branches containing same mode from N second optical branches containing different modes, divide out part of light in each third optical branch having been converted from first polarization state to second, and form first polarization state again, combine and demodulate light in the first polarization state without conversion in original third optical branch after having been divided into M second optical sub-branches according to M wavelengths respectively. Thus increasing both communication rate and bandwidth effectively.

A reception device includes a reception unit that receives a signal obtained by polarization multiplexing of an X polarized wave and a Y polarized wave, converts a received signal into a received signal corresponding to each of the X polarized wave and the Y polarized wave, and outputs the received signal, a first signal decoding unit that decodes one series of transmission signals from the received signal output by the reception unit, a polarization separation unit that performs polarization separation on the received signal corresponding to each of the X polarized wave and the Y polarized wave and output by the reception unit, a second signal decoding unit that decodes the received signal polarization-separated by the polarization separation unit, and a first polarization processing switching unit that captures a received signal corresponding to each of the X polarized wave and the Y polarized wave and output by the reception unit, and switches an output destination of the received signal that has been captured to one of the first signal decoding unit and the polarization separation unit on the basis of information indicating a modulation method.

In a transmission terminal (1), a control unit (101) selects number of parallelizations, and a parallelization unit (103) parallelizes data according to the number of parallelizations selected by the control unit (101); and in a reception terminal (2), a demodulation unit (205) and a demapping unit (206) perform processing according to the number of parallelizations.

Various example embodiments of a wavelength division multiplexing (WDM) direct detection (DD) system are presented. The WDM DD system may be configured to support WDM within the context of any WDM system supporting communication of wavelength channels based on modulation formats recoverable by direct detection (e.g., based on intensity-modulated (IM) signals within the context of a WDM IM-DD system, single-sideband (SSB) signals within the context of a WDM SSB-DD system, or the like). The WDM DD system may be configured to support WDM within the context of a WDM DD system, based on labeling of the wavelength channels with a set of states of spatial mode and polarization (SoSPs), based on use of an SoSP labeler on the transmit side to associate SoSPs with the wavelength channels and based on use of a receiver on the receive side to detect the SoSPs and recover the wavelength channels based on the SoSPs.

This makes it possible to mitigate performance degradation caused by mode-dependent losses without significantly increasing computational complexity. [Solution] The signal processing circuit includes a MIMO demodulation unit that includes a first MIMO filter and performs MIMO demodulation processing on multiple signals; a signal extraction unit that extracts a signal of a predetermined time slot from the output signal of the MIMO demodulation unit; a removal component generation unit that includes a second MIMO filter and generates a signal component to be removed, including interference components that occur between multiple modes, based on the signal output from the MIMO demodulation unit; an interference removal unit that generates a signal from which the signal component to be removed has been removed from the signal extracted by the signal extraction unit; and a coefficient control unit that uses the magnitude of the difference between the signal from which the signal component to be removed has been removed and a reference signal as a loss function, and adaptively controls the coefficients of the first MIMO filter and the second MIMO filter, respectively, using backpropagation and gradient descent.

In optical interconnect systems, information may be encoded in different wavelengths of light in an optical signal in a wavelength division multiplexing (WDM) scheme. The inventors have recognized and appreciated that the data rate of an optical interconnect system may be doubled by employing a polarization multiplexing scheme, where some information is encoded in an optical signal having a first polarization state and other information is encoded in an optical signal having a second, orthogonal polarization state as the different polarizations will act independently while propagating along a fiber. Accordingly, described herein are systems and techniques for optical interconnect systems employing polarization multiplexing.

This transparent optical repeater, configured to be embedded onboard a satellite, includes a set of optical fibers, a first optical head, a low-noise optical amplifier, and a polarization separator and controller including a channel polarization separator and controller for each output channel of the band-pass filter. The repeater further include a third high-power optical amplifier per output channel of the polarization separator and controller, an orthogonal polarization combiner configured to recombine the two respective output channels of the two optical multiplexers, and a second optical head configured to transmit the output optical signals of the orthogonal polarization combiner.

Described herein are systems and techniques for a bidirectional polarization diverse optical transceivers. When an optical signal propagates along a single mode fiber, the single polarization mode gets rotated and may arrive at an optical transceiver with an arbitrary superposition of two orthogonal polarization modes, each of which experience differing optical effects. The bidirectional optical transceivers described herein include one or more features for addressing the differing optical effects so that both polarization modes are received at substantially a same time.

The present disclosure relates to generating optical PAM-4 signals in Mach-Zehnder modulators. Embodiments are disclosed for generating an optical pulse amplitude modulation 4-level (PAM-4) signal from a bandwidth-limited duobinary electrical signal in a Mach-Zehnder modulator. An example system includes an MZM structure including a first waveguide interferometer arm structure associated with a first semiconductor device and a second waveguide interferometer arm structure associated with a second semiconductor device. A multi-binary electrical signal is applied to the first semiconductor device and the second semiconductor device or between the first semiconductor device and the second semiconductor device to convert an input optical signal provided to the MZM structure to an optical PAM-4 signal.

In an optical multiplexer, a first Mach-Zehnder interferometer (MZI) generates a first intermediate optical signal based on i) a first input optical signal at a first wavelength, and ii) a second input optical signal at a second wavelength. A second MZI generates a second intermediate optical signal based on i) a third input optical signal at a third wavelength, and ii) a fourth input optical signal at a fourth wavelength. A polarization combiner rotator (PCR) is coupled to the first MZI and the second MZI. The PCR generates an output optical signal based on i) the first intermediate optical signal received at a first input of the PCR, and ii) the second intermediate optical signal received at a second input of the PCR. The output optical signal includes the first input optical signal, the second input optical signal, the third input optical signal, and the fourth input optical signal.

Techniques are described for implementing an out-of-band communication channel used to exchange control channel information in sub-carrier-based optical communication systems. In an example implementation, a transmitter includes a laser operable to supply an optical signal, a digital signal processor operable to supply first electrical signals based on first data input to the digital signal processor and second data input to the digital signal processor, digital-to-analog conversion circuitry operable to output second electrical signals based on the first electrical signals, modulator driver circuitry is operable to output third electrical signals based on the second electrical signals, and an optical modulator operable to supply first and second modulated optical signals based on the third electrical signals. The first modulated optical signal includes a plurality of optical subcarriers carrying user data. The second modulated optical signal is polarization modulated based on the second data.

The application relates to an automatic polarization controller-based optical transmission system for short-distance high-capacity optical interconnection, comprising an optical transceiver module, an automatic polarization controller and a MIMO-free structure DSP module. The optical transceiver module divides the outgoing light field of a transmitting end laser into two parts, one part of which is modulated to obtain signal light, and the other part is used as pilot light. After passing through the automatic polarization controller, the pilot light is fed to the receiving end of the optical transceiver module together with the signal light for coherent detection, and the receiving signal is recovered through the MIMO-free structure DSP module. Meanwhile, a simple training sequence is adopted to solve the mismatch between the signal light link and the pilot light link. The application solves the problem that high-speed coherent optical communication technology is restricted by cost, bandwidth, power consumption and integration, and cannot be used in short-distance optical interconnection scenes.

The present invention addresses the problem of providing a compact optical coupling system having a simple structure and an optical communication device using the same. The problem is solved by an optical coupling system (1) that couples a multicore fiber (10) and a coupling target device (18) together via a combination of a polarized beam control element (14) facing a light entering / emitting surface (12) of the multicore fiber (10) and a polarization selective diffraction element (17) which is positioned on a side of the polarized beam control element (14) opposite to the emitting surface of the multicore fiber (10) and which faces the coupling target device (18).

The present disclosure relates to an optical transmitter for transmitting a data signal. The optical transmitter comprises an encoder. The encoder encodes the data signal by selecting based on a bit sequence a first symbol and a second symbol from a set of four quadrature phase shift keying (QPSK) symbols for each one of at least two transmission time slots. The optical transmitter further comprises a modulator. The modulator uses in each transmission time slot the first symbol to modulate a first carrier wave and the second symbol to modulate a second carrier wave, and transmits the two carrier waves over orthogonal polarizations of an optical carrier.

This transparent optical repeater, configured for onboard satellite deployment, 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); - an orthogonal polarization combiner (PBC), configured to recombine the two respective output channels of the two optical multiplexers (HPWDM); and - a second optical head (OHU2) configured to output the optical signals from the orthogonal polarization combiner (PBC).

The application provides a broadband wavelength-polarization-mode (de)multiplexing chip and a cross-wavelength supporting method. The chip comprises a signal coupling module, a signal light conversion module and a cross-wavelength signal light uploading / download module. The signal conversion module is formed by introducing a specific structure on at least one transmission waveguide. The cross-wavelength signal light uploading / download module is formed by at least one coupling structure and a specific etching structure introduced in the coupling structure. The application locally processes the whole silicon-based optoelectronic integrated chip required for multi-wavelength hybrid multiplexing, realizes low transmission loss and low crosstalk (de)multiplexing, and provides a flexible multi-wavelength hybrid multiplexing platform for the silicon-based optoelectronic integrated chip.

Described herein are systems and techniques for a bidirectional polarization diverse optical transceivers. When an optical signal propagates along a single mode fiber, the single polarization mode gets rotated and may arrive at an optical transceiver with an arbitrary superposition of two orthogonal polarization modes, each of which experience differing optical effects. The bidirectional optical transceivers described herein include one or more features for addressing the differing optical effects so that both polarization modes are received at substantially a same time.

The present application relates to a coherent free space optical communication system expansion method, and belongs to the field of optical communication, which solves the problem of poor correction effect of existing systems under strong turbulence and mobile platform adaptability. The transmitting end adopts circular polarization SPPSK modulation, divides the static wavefront into N independent regions, each region maps bit information with orthogonal circular polarization state, generates a spatial polarization beam and sends it to the receiving end; the V-AO system of the receiving end adopts the EPSA-DE algorithm, generates control voltage through iterative optimization, and drives the correction element to jointly correct the phase and polarization aberrations caused by atmospheric turbulence; the corrected beam is mixed and demodulated to recover the original data. The present application does not need strict alignment between the transmitting end and the receiving end through circular polarization SPPSK modulation, is suitable for mobile platforms, and improves the correction effect and stability under strong turbulence through the EPSA-DE algorithm, significantly expanding the communication capacity of the system.

Injection-locked transmitter for an optical communications network, comprising: a master seed laser source input that is limited to a single longitudinal mode; an input data stream; and a laser-injected modulator comprising at least one slave laser with a resonator frequency locked to a frequency of the single longitudinal mode of the master-seed laser source, wherein the laser-injected modulator is configured to receive the master-seed laser source input and the input data stream and to output a laser-modulated data stream, characterized by the fact that the transmitter further comprises: a first optical circulator in communication with the laser-injected modulator and the master-seed laser source input; a second optical circulator in one-way communication with the first optical circulator and in two-way communication with the at least one slave laser; and an external modulation element located between the first optical circulator and the second optical circulator, wherein the external modulation element is configured to receive the input data stream and an output from the second optical circulator, where the first optical circulator is in one-way communication with an output of the external modulation element.

Optical communication devices and associated methods of manufacturing are provided. An example optical communication device includes a substrate defining a first end and a second end. The optical communication device also includes a primary optical communication medium attached to the second end and a secondary optical communication medium attached to the second end. The optical communication device further includes a signal preclusion component supported by the substrate that selectively preclude signal transmission of optical signals received via the first end to either the primary optical communication medium or the secondary optical communication medium.