266results about "Electromagnetic repeaters" patented technology

There is provided a technique for implementing instantly responsive communication flexibly by setting communication occasions in an on-demand manner that are not included in a communication plan scheduled in advance for inter-satellite optical communication. One aspect of the present disclosure relates to a satellite including an optical signal obtainer that captures an optical beacon transmitted from a relay satellite in response to a communication request received from an earth station, an image processor that retrieves a bright spot in a captured image frame, an optical beacon detector that detects the optical beacon based on a flickering state of the retrieved bright spot, and an optical communicator that establishes inter-satellite optical communication with the relay satellite based on the detected optical beacon.

The invention discloses a ship-shore safety connection system with efficient communication and safety protection, and particularly relates to the technical field of electric power and data connection of ships and shore bases, which comprises a medium-voltage composite optical fiber shore power cable, a dual-system electrical transmission system, a third-party linkage control center and a layered insulation monitoring module, the medium-voltage composite optical fiber shore power cable adopts a double-layer anti-torsion protective sleeve and an anti-electrostatic shielding layer, a double-system electrical transmission system is integrated with a broadband voltage self-adaptive module and a high-speed optical fiber communication repeater, the system realizes ship-shore potential difference monitoring and redundancy switching through a three-way data link, and a layered insulation monitoring module is used for positioning a fault point in real time. Besides, an environment reinforcing assembly, a multi-stage early warning mechanism and a communication line self-healing function are further arranged, the problems that a traditional system is poor in compatibility, low in communication efficiency and insufficient in safety protection are solved, and the system is suitable for efficient and safe connection between the ship and the shore base.

A self-aligning window mounted communication apparatus is discussed herein. In some examples, a wireless gateway may comprise a first unit to be mounted outside a window and a second unit to be mounted inside the window. A first unit and a second unit may each include an optical unit, a coupling unit, and a housing unit. A first optical unit may include a magnetic array with polarities of the magnetic elements configured to orient with a second optical unit in a single orientation. The optical unit(s) may be movably coupled with the respective coupling unit(s) so that the optical unit may move with various degrees of freedom and thus, when the first and second units are mounted on a window, the optical units can self-align based on the respective magnetic arrays and the degrees of freedom afforded by the movable coupling with the coupling unit.

The invention discloses a photon-assisted terahertz signal transmission system and method. The photon-assisted terahertz signal transmission system comprises a terahertz signal photon generation module, a transmission module and a photoelectric conversion module which are connected in sequence, the terahertz signal photon generation module is used for generating an optical signal containing a terahertz signal; the transmission module is used for transmitting optical signals containing terahertz signals at different distances and sending the optical signals to the photoelectric conversion module; and the photoelectric conversion module is used for converting the received optical signal containing the terahertz signal into the terahertz signal. The multi-channel multi-band signal generation is realized by arranging one laser, the use of an external cavity laser to reduce the phase noise of the generated signal is avoided, in addition, the optical fiber is used for long-distance transmission, and the technical problem that long-distance communication cannot be realized in the prior art is solved.

The embodiment of the invention provides a gain regulation and control precision maintenance method for a programmable Raman amplifier. The method comprises the following steps: acquiring basic scene sample data and target scene sample data to form a source domain sample data set and a target domain sample data set; selecting a proper machine learning method as a basic learning algorithm according to the characteristics of the data in the data set; initializing weights occupied by a source domain sample and a target domain sample; fitting a prediction model by adopting a basic learning algorithm according to the weights of the source domain sample and the target domain sample; re-weighting the source domain sample and the target domain sample according to the total weighting error of the target domain sample so as to correct the difference between the distribution of the source domain sample and the distribution of the target domain sample; and obtaining a model after multiple iterations as a pumping prediction model of the programmable Raman amplifier. When the use scene of the programmable Raman amplifier changes and the accuracy of the regulation and control algorithm of the programmable Raman amplifier is reduced, by means of the method, maintenance of the gain regulation and control precision of the programmable Raman amplifier can be achieved by collecting a small amount of sample data, and the use scene of the programmable Raman amplifier is effectively expanded.

An optical transmission system includes a transceiver configured to output an optical signal to a first optical fiber core, wherein the first optical fiber core is configured to reflect a portion of the optical signal back toward the transceiver. The optical transmission system further includes a second optical fiber core proximate the first optical fiber core, wherein the second optical fiber core is configured to receive crosstalk of the reflected portion of the optical signal from the first optical fiber core. The optical transmission system further includes a detector configured to receive the crosstalk of the reflected portion of the optical signal and generate detection data based on the crosstalk of the reflected portion of the optical signal. The optical transmission system further includes a controller configured to receive information related to the detection data, and determine whether the optical transmission system is functioning properly based on the detection data.

The invention relates to the technical field of optical fiber communication, and discloses an optical fiber optical frequency relay transmission system and method without a phase-locked loop. The optical fiber optical frequency relay transmission system comprises multiple stages of relay stations which are sequentially cascaded through an optical fiber transmission link, and for each stage of relay station, a first photoelectric detector is used for carrying out beat frequency processing on a current-stage optical frequency signal sent by a current-stage regeneration cavity-stabilized laser and an optical frequency signal received from a previous-stage relay station; frequency mixing and summation are carried out on the current-level beat frequency signal and an optical frequency signal transmitted by an upper-level relay station through the data interaction unit, so that noise accumulation generated in a signal transmission process in a traditional phase-locked loop scheme can be thoroughly eliminated; therefore, the noise item in the optical frequency signal output to the user side is completely counteracted, that is, the high-precision original optical frequency signal is provided for the user side, and long-distance and high-precision optical frequency transmission can be realized on the basis of reducing the complexity of system design.

This application provides a photoelectric amplification circuit and a signal processing method. The photoelectric amplification circuit includes a first photodiode and a second photodiode that are connected in parallel. A Doherty circuit structure is used, so that power supply efficiency of the photodiode in a back-off state can be improved. In addition, an impedance modulation unit is used, to implement dynamic load conversion from a back-off point to a maximum output point. This helps maintain high output efficiency of the first photodiode and the second photodiode in an interval between the maximum power point and the back-off point.

The invention discloses a relay station for digitally locking an optical fiber link and monitoring phase noise in real time, which belongs to the technical field of relay stations for optical fiber optical frequency transmission and comprises a main control circuit, a link locking circuit and a laser locking circuit. The link locking circuit is bidirectionally connected with the main control circuit, the link locking circuit sends a link locking error signal to the main control circuit, and the main control circuit sends a link locking instruction to the link locking circuit; the laser locking circuit is bidirectionally connected with the main control circuit, the laser locking circuit sends a laser locking error signal to the main control circuit, and the main control circuit sends a laser locking instruction to the laser locking circuit; the link locking circuit comprises an optical frequency digital phase-locked loop; and the optical frequency digital phase-locked loop adopts a DDS (Direct Digital Synthesizer) to drive an acousto-optic modulator to adjust the frequency and the phase of an optical frequency signal. An optical frequency digital phase-locked loop is adopted to measure a phase noise power spectrum in real time, link locking can be achieved, and meanwhile whether the power spectrum of a locked signal reaches a theoretical noise suppression limit or not can be judged.

The invention discloses an optical fiber relay aircraft, a drive-by-wire unmanned aerial vehicle system and a flight control method and device, relates to the technical field of unmanned aerial vehicle communication, and aims to solve the problem that the maneuverability of a drive-by-wire unmanned aerial vehicle is poor due to the fact that optical fibers are limited by terrains or obstacles. The optical fiber relay aircraft is connected with the drive-by-wire unmanned aerial vehicle through an optical fiber, the optical fiber relay aircraft comprises a connecting device, and the connecting device is connected with the optical fiber and used for lifting the optical fiber along with the optical fiber relay aircraft and hovering the optical fiber in the air. The drive-by-wire unmanned aerial vehicle system comprises a drive-by-wire unmanned aerial vehicle and the optical fiber relay aircraft, and the drive-by-wire unmanned aerial vehicle and the optical fiber relay aircraft are connected through an optical fiber. According to the embodiment of the invention, the drive-by-wire unmanned aerial vehicle can fly flexibly in a complex environment.

A communication planning device according to an aspect of the present disclosure comprises: an orbit prediction unit that predicts the orbit of a relay satellite that relays communication between a satellite having an optical communication unit and an earth station; and a creation unit that creates, on the basis of the predicted orbit, control information for controlling the optical communication unit so that the optical communication unit is directed to and tracks the relay satellite in a non-planning communication period.

The invention belongs to the technical field of communication, and discloses a communication device based on an underwater blue-green light connector, which is composed of a blue light connector and a green light connector, adopts laser as a communication carrier, loads binary data flow onto the laser and sends the binary data flow to a PMT (photomultiplier); and the PMT converts and demodulates the received laser signal and outputs the converted and demodulated laser signal to a using terminal. Compared with wired communication, the device has the advantages that the AUV can move more flexibly in a larger range; compared with sound communication, higher-speed transmission can be carried out, and the problem of communication of the AUV under the short-distance condition is solved; compared with traditional laser communication, the device is high in stability, optical divergence design and high-dynamic-range gain design are added into the device, and the stability of a channel can be kept under the condition of water turbulence.

A regenerative relay transponder includes: an optical receiving unit that receives an optical signal from a transmitting device as a reception optical signal and converts the reception optical signal into an electrical signal; an electrical-signal processing unit that executes predetermined processing on the electrical signal; an optical transmitting unit that generates a transmission optical signal by converting the electrical signal subjected to the predetermined processing into an optical signal and transmits the transmission optical signal; and a monitoring unit that monitors the predetermined processing by the electrical-signal processing unit, wherein the monitoring unit accumulates in a storage unit monitoring data, which indicates the result of the monitoring, over a predetermined period and causes a communication unit to transmit the monitoring data accumulated over the predetermined period as transmission data to the transmitting device.

The present application provides a secure repeater-based quantum communication method and communication network. Said method comprises a transmitter encrypting plaintext information to be sent, to obtain ciphertext; the transmitter sending the ciphertext to a repeater node by means of a quantum communication protocol, so as to send the ciphertext to a receiver by means of at least one repeater node; and after receiving the ciphertext, the receiver decrypting the ciphertext to obtain the plaintext information. The ciphertext is transmitted step by step by means of the at least one repeater node, which is not limited to the distance between the transmitter and the receiver, so that the ciphertext can be transmitted over a long distance. Furthermore, before arriving at the receiver, the plaintext information is transmitted in the form of a ciphertext and is decrypted on the fly, thereby reducing the risk of information being eavesdropped, improving the security.

Techniques are described for implementing free space optical (FSO) ground-to-satellite communications. In general, an optical ground station communicates optically with a satellite via a ground-to-satellite FSO communication link. Embodiments described herein deploy at least two FSO relays at one or more aerial platform altitudes to effectively segment the ground-to-satellite FSO communication link into three or more FSO sub-links. Each FSO sub-link has better optical link performance (e.g., lower outage probability) than a single direct link. The FSO relays can include tropospheric FSO relays on low-altitude platforms and / or stratospheric FSO relays on high-altitude platforms, and architectures can use the FSO relays in a serial and / or parallel manner.

The application discloses a kind of photonic-assisted terahertz signal transmission system and method, including the terahertz signal photon generation module, transmission module and photoelectric conversion module connected in turn;The terahertz signal photon generation module is used to generate the optical signal containing terahertz signal;The transmission module is used to transmit the optical signal containing terahertz signal at different distances, and send it into photoelectric conversion module;The photoelectric conversion module is used to convert the received optical signal containing terahertz signal into terahertz signal.Setting a laser realizes multiple multi-band signal generation, avoids using external cavity laser to reduce the phase noise of generated signal, in addition, long-distance transmission is carried out using optical fiber, solve the technical problem that prior art cannot realize long-distance communication.

A passive optical network system having a node that is optically coupled to optical line terminals (OLTs), and that is optically coupled to optical network units (ONUs). The node includes at least one fiber link module (FLM), each FLM including an upstream multiplex conversion device (MCD), and a downstream MCD. The upstream MCD receives an upstream optical signal from the ONUs, converts the upstream optical signal to an upstream electrical signal, and transmits a regenerated upstream optical signal to the OLTs. The downstream MCD receives a downstream optical signal from the OLTs, converts the downstream optical signal to a downstream electrical signal, and transmits a regenerated downstream optical signal to the ONUs.

A method and system for dual-hop quantum communication utilizing a quantum source node, a plurality of quantum repeaters, and a quantum receiver. The method involves transmitting, by a quantum source node teleporter, a message containing at least one superconducting qubit to multiple quantum repeaters over time-varying amplitude damping channels. Each quantum repeater measures a first hop relaxation time, estimates a second hop relaxation time, and calculates a minimum composite relaxation time. The minimum composite relaxation times are transmitted to the quantum source node, which selects the quantum repeater with the largest composite relaxation time to forward the message during the second hop. The selected quantum repeater transmits the message to the quantum receiver, establishing entanglement between repeater memory qubits and receiver memory qubits. The invention further includes methods for estimating quantum outage probabilities and utilizing error correction to ensure reliable quantum communication.

The invention provides an apparatus for quantum communication in a quantum network configured to create an entangled pair of quantum information carriers comprising a first quantum information carrier and a second quantum information carrier, transmit the first quantum information carrier to a remote device, store the second quantum information carrier in a quantum memory, receive, from the remote device, information about a phase correction related to the transmission of the first quantum information carrier, and apply the phase correction to the second quantum information carrier.

This invention discloses a high-speed direct-modulation direct-detection passive optical network (SOA) receiver control method and system, relating to the field of optical access network technology. The high-speed direct-modulation direct-detection SOA receiver control method includes the following steps: amplifying the received optical signal and calculating the corresponding received power and bit error rate; using the received power and bit error rate as control parameters, performing closed-loop control to determine the optimal optical signal amplification amplitude. This invention enables the SOA output signal to be at the optimal received amplitude at the receiver, thereby increasing the receiver's power budget.

The application discloses a self-adaptive Raman gain compensation system and method, and relates to the technical field of optical communication, wherein the self-adaptive Raman gain compensation system comprises: an optical fiber link; a Raman optical amplifier used for amplifying an input optical signal transmitted by the optical fiber link; a centralized optical amplifier used for amplifying an optical signal output by the Raman optical amplifier; and a compensation device used for acquiring and comparing partial optical powers of the input optical signal and the optical signal output by the centralized optical amplifier, and controlling the gain of the centralized optical amplifier based on a comparison result. The application can realize self-adaptive gain compensation when the gain of the Raman amplifier is insufficient.

The utility model relates to an optical communication coupling module. The optical communication coupling module comprises at least one photodiode, an analog-to-digital converter, and a variable resistor or a digital-to-analog converter. The photodiode is used for detecting the quantity of laser light; an analog-to-digital converter connected to the photodiode; the variable resistor is connected to the photodiode, and the digital-to-analog converter is connected to the analog-to-digital converter; according to a comparison result of an input voltage of the photodiode and a threshold voltage, a resistance value of the variable resistor is adjusted, or a reference voltage of the analog-to-digital converter is adjusted, so that whether the analog-to-digital converter is started or not is determined, and the analog-to-digital converter is in a dynamic range.

A disclosed optical system comprises a repeater disposed between a first span and a second span of an optical cable and a node receiving an optical signal from the first span and transmitting a reflection to the first span. The node comprises a transmitter coupled to the first span to transmit the optical signal, transmit pulses having an RF modulated tone, and provide a local reflection; a receiver to receive the local reflection and the pulse reflection and passing a filtered spectrum; and a DSP to: determine a first RF phase of the local reflection and a second RF phase of the pulse reflection; determine a second RF phase; determine a first span seismic pressure based on the first RF phase and determine a second span seismic pressure based on the second RF phase.

An optical transceiver (101) of an optical relay apparatus includes: a coherent reception front-end unit (110) that coherently detects an input optical signal to be input, based on local oscillation light, and outputs the coherently detected first analog electric signal; a coherent transmission front-end unit (120) that coherently modulates a second analog electric signal acquired by turning around the first analog electric signal, based on transmission light, and outputs the coherently modulated output optical signal; and an analog compensation unit (130) that performs analog signal processing on the first analog electric signal in such a way as to compensate for signal quality according to a signal characteristic between an input of the coherent reception front-end unit (110) and an output of the coherent transmission front-end unit (120), and thereby generates the second analog electric signal.

An aspect of the present invention is an optical transmission system in which one or more optical transmitters and one or more optical receivers perform communication via an optical transmission path, the optical transmission path including a plurality of relay nodes including optical amplifiers that amplify optical signals, the one or more optical transmitters transmitting optical signals at a plurality of channel frequencies, the one or more optical receivers estimating variations in intensities of the optical systems on the optical transmission path for each of the plurality of channel frequencies, the optical transmission system including: a network controller that acquires estimation information indicating a result of estimating the variations from the one or more optical receivers and acquires gain spectra of the optical amplifiers in the optical transmission path on the basis of the acquired plurality of pieces of estimation information.

To provide a wireless communication system capable of suppressing characteristic degradation of an RF signal and improving communication quality in a DAS using analog RoF.SOLUTION: A wireless communication system multiplexes a TDD signal, an RF signal synchronized with timing of the TDD signal, and a DL control signal and a UL control signal synchronized with the timing of the TDD signal, between an A-RoF master unit 2 and an A-RoF slave unit 30, a frequency of the DL control signal and a frequency of the UL control signal are made the same, and a control signal of downlink is synchronized with the RF signal of uplink, and the control signal of uplink is synchronized with the RF signal of downlink.SELECTED DRAWING: Figure 1

Embodiments of the present disclosure generally relate to systems, methods, and articles of manufacture for using a fiber laser with wavelength division multiplexers (WDMs) for a variety of purposes. For example, implementations described herein may be used with high-power Raman fiber laser (RFL) systems, or the like. A laser system is provided that may include a fiber laser; a laser path comprising optical fiber; and a plurality of wavelength division multiplexers (WDMs) positioned within the laser path coupling the optical fiber; wherein at least one of the plurality of WDMs has the widest wavelength spacing and is positioned first in the laser path, thereby providing increased power stability.

A method includes: outputting optical signals to a first optical fiber via a first interrogator, the first interrogator located at a topside / onshore location, the first interrogator configured to collect distributed acoustic sensor (DAS) and / or distributed temperature sensor (DTS) measurements; outputting optical signals to a second optical fiber via a second interrogator, the second interrogator located subsea, the second interrogator configured to collect DAS and / or DTS measurements; receiving optical signals from the second optical fiber via the first interrogator; receiving optical signals from the first optical fiber via the second interrogator; providing acoustic, temperature, and / or vibration sensing along a portion of the second optical fiber via the first interrogator based on the optical signals received from the second optical fiber; and providing acoustic, temperature, and / or vibration sensing along a portion of the first optical fiber via the second interrogator based on the optical signals received from the first optical fiber.

The invention describes a tsunami warning system utilizing properties of light in optical fibers within submarine telecommunication cables. Enhanced by microwave frequency modulation and High-Loss Loop Back (HLLB) techniques, this system measures photoelastic changes for more stable, long-period tsunami wave detection.

An adjustable frequency optical repeater is provided that includes an acousto-optic device (AOD) in a double-pass configuration. The AOD is configured to receive (a) an input beam propagating in a first direction toward the AOD from a first side of the AOD and (b) an electrical drive signal. The optical repeater also includes an array of output optical elements that includes a plurality of output optical elements disposed on the first side of the AOD. Each output optical element of the plurality of output optical elements is configured to provide a respective output beam that propagates substantially parallel to a second direction or antiparallel to the second direction. The plurality of output optical elements are spaced apart from one another in a third direction that is transverse to both the first direction and the second direction.