126 results about "Free-space optical communication" patented technology

The invention relates to a coarse-fine integrated pointing mechanism for optical communication, and belongs to the field of optical communication equipment. The problems that in the prior art, a coarse pointing mechanism and a fine pointing mechanism are separated, so that the size is large, and cooperative work efficiency is low are mainly solved. The technical scheme is characterized in that the coarse pointing function and the fine pointing function are integrated into a single compact structure, large-range coarse adjustment around an azimuth axis y1 is achieved through a rotary table on a base, and high-precision fine adjustment around a pitch axis x2 and an azimuth axis y2 is achieved through a reflector supporting frame and a reflector on a mounting piece; the first motor, the second motor and the third motor respectively drive; full-state sensing is performed through a multi-axis angle sensor, a light beam position detector and a temperature monitoring module; and the controller performs real-time thermal error feedforward compensation on the driving instruction of the fine pointing motor according to the temperature monitoring data and a pre-stored thermal deformation compensation model. The mechanism is mainly used in a free space optical communication system, and realizes rapid capture, high-precision alignment and stable tracking of light beams.

The invention relates to the field of optical communication, and provides a free space optical communication-based full-duplex signal transmission device, which comprises a rotatable first device and a rotatable second device, the rotation axes of the first device and the second device coincide; when the first device and / or the second device rotate around the rotation axis, an optical signal transmitted by the first laser transmitter is always received by the first laser receiver, so that the intensity of light received by the first laser receiver is not changed during rotation; and when the first device and / or the second device rotate around the rotation axis, the optical signal transmitted by the second laser transmitter is received by one second laser receiver or at least two adjacent second laser receivers. According to the invention, high-speed full-duplex signal transmission in a rotation state can be realized, transmission rates such as 10Gbps and 25Gbps are supported, the sizes of the first device and the second device are as small as several millimeters, the size is small, and the weight is light.

The invention discloses a wavefront distortion correction method based on a dynamic adaptive MESSA algorithm and a coherent free space optical communication system. The problems that an existing method is prone to falling into a local optimal solution, the correction effect is poor under dynamic turbulence, and the adaptive capacity is weak are solved. According to the method, an individual position is initialized through a Circle chaotic mapping method, iterative optimization is carried out in combination with a Levy flight strategy and a variable spiral search strategy, and a step size control parameter, a safety threshold, spiral strength and a spiral adjustment coefficient are dynamically adjusted through a double-discrimination dynamic adaptive parameter adjustor. And reducing the population scale according to a nonlinear population reduction strategy, finally outputting an optimal individual position, and driving the deformable mirror to perform wavefront correction according to a control voltage vector corresponding to the optimal individual position. According to the invention, the dynamic adjustment of the algorithm parameters and the population structure is realized, and the adaptability, convergence speed and stability of the wavefront distortion correction method in the dynamic turbulence environment are enhanced.

The invention relates to the technical field of free space optical communication, and discloses a wireless optical communication device which comprises a transmitting end and a receiving end. The transmitting end comprises an information source generation unit, a coding unit, a modulation unit, a driving unit, a light source unit and a transmitting optical assembly; the receiving end comprises a receiving optical assembly, a CCD camera, a signal processing unit, a demodulation unit and a decoding unit; in actual use, wireless communication is carried out through the optical medium, the communication medium is safe, and the problems of active electromagnetic silence and passive electromagnetic suppression do not need to be worried about; the coverage range of visible light is wide, the communication range is wide, and deployment is convenient; in addition, communication is carried out through the CCD camera, so that the original CCD camera can be replaced in some scenes where the CCD camera is installed, and image shooting and wireless optical communication can be realized at the same time.

The invention discloses an atmospheric turbulence phase screen generation method based on layered physical constraints, and belongs to the crossing field of optical communication and artificial intelligence. According to the method, a diffusion probability model is combined with layered atmospheric physical constraints, independent physical constraint loss functions are established for a boundary layer, a troposphere and a stratosphere of the atmosphere, and it is ensured that a generated phase screen conforms to turbulent flow statistical characteristics of all layers through power spectrum density constraints and structure function constraints; enhancing feature learning of each layer of phase screen by adopting a physically guided attention mechanism; and designing a time-dependent constraint weight strategy, and adaptively adjusting the physical constraint strength in the diffusion denoising process. The method solves the technical problems that the vertical layering difference is ignored, the physical consistency is insufficient, and the generation quality depends on a large amount of labeled data in the existing method, is particularly suitable for high-fidelity atmospheric turbulence modeling of a satellite laser communication link, and can also be widely applied to the fields of free space optical communication system simulation, adaptive optical system design and the like.

The invention relates to the technical field of free space optical communication, in particular to an atmospheric turbulence adaptive optical compensation method for wireless laser communication, which comprises the following steps of: performing light beam coarse tracking by using a fast reflector to eliminate tilt drift; monitoring the received light intensity of the wavefront sensor in real time, and setting a threshold value for mode judgment; when a channel is good, a Kalman filtering algorithm is adopted to predict and compensate system delay, modal decoupling is carried out on reconstructed wavefront, a large-stroke deformable mirror is controlled to correct low-frequency large-amplitude aberration, and a micro-electro-mechanical deformable mirror is controlled to correct high-frequency residual error; and when the channel is in deep fading or the detector fails, the blind optimization mode is automatically switched, the state of the large-stroke deformable mirror is locked, and SPGD iterative control is applied to the micro-electro-mechanical deformable mirror based on the communication light intensity. According to the invention, through a double-deformable mirror frequency division cooperation and hybrid sensing strategy, the problems of insufficient bandwidth, limited stroke, easy interruption and the like of a traditional system under strong turbulence are effectively solved, and the optical fiber coupling efficiency and the robustness of a communication link are significantly improved.

The invention provides a laser communication terminal based on an ultra-compact wave combining laser. The laser communication terminal comprises a wave combining laser module, an optical antenna module, a light splitting module, a beacon receiving module and a signal receiving module. The wave combining laser module is used for combining laser beams with different wavelengths into a main laser beam through a space path. The optical antenna module is used for expanding and collimating the main laser beam, then emitting the main laser beam, and receiving an external incident laser beam. And the light splitting module is used for carrying out polarization state and wavelength separation on the main laser beam and an external incident laser beam, guiding the main laser beam to the optical antenna module, and respectively guiding the external incident laser beam to the beacon receiving module and the signal receiving module. The beacon receiving module is used for acquiring position information, and the signal receiving module is used for acquiring communication information. According to the invention, the laser communication terminal structure with integrated emission and reception, miniaturization and high precision is realized, and the laser communication terminal structure is suitable for free space optical communication and other application scenes.

Improved systems and methods for optical communications are provided that have reduced size, weight, and power use. Such system and methods can find, use between satellites or other distant systems that are in significant relative motion. Such embodiments include the use of a diamagnetically levitated magnetic actuator or other actuator to control the orientation of an optical phased array (OPA), thereby aiming the array at distant target systems. An OPA has reduced size and mass relative to traditional telescopes, providing similar beam apertures while having reduced size, weight, and cost of the OPA and associated actuators. The actuator allows the OPA to omit, or to include fewer, phase shifter elements than previous steerable OPA telescopes, reducing complexity', cost, and power requirements.

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 invention discloses a free space optical communication system based on a structured optical frequency comb, and belongs to the field of optical communication. Comprising an optical frequency comb generation system, a signal coding system, a spatial light modulation and demodulation system and a signal receiving system. The optical frequency comb generation system is used for modulating input continuous laser into an adjustable optical frequency comb with high repetition frequency, short pulse width and high power; the signal coding system is used for separating the light with different wavelengths in the optical frequency comb, independently coding the light with each wavelength, and finally combining the light with different wavelengths again; the spatial light modulation and demodulation system is used for coupling the Gaussian beam in the optical fiber into a free space and converting the Gaussian beam into structured light, demodulating the structured light after the structured light is transmitted to a receiving end and re-coupling the structured light back to the optical fiber; the signal receiving system is used for receiving and analyzing the optical signals. According to the invention, the optical frequency comb and the structured light are combined, and the problem that optical signals are easily influenced by atmospheric turbulence in free space optical communication can be effectively solved on the premise of ensuring large communication capacity.

The application discloses a free space optical communication real-time regulation system based on light top technology, and belongs to the field of space optical communication. An AMCC transmitting module superimposes an AMCC signal on a service signal to form a mixed optical signal by controlling the bias voltage of a VOA; the mixed optical signal is transmitted to a free space channel through a space optical lens group; a beam splitter divides the received optical signal into communication side information and control side information; on the control side, the optical signal is received by an APD and converted into an electrical signal, which is sent into an AMCC receiving module after being sampled by an ADC, and the regulation information is fed back to a coherent receiver after being processed; the coherent receiver receives the regulation information to regulate the board card state in real time; the application is based on AMCC technology, utilizes the parallel processing capacity of a field programmable gate array (FPGA), and realizes efficient regulation of free space optical communication.

The invention discloses a vortex beam orbital angular momentum detection device and method based on a well-shaped line structure. The device sequentially comprises a well-shaped line structure and a focusing lens in the light path direction. A vortex light beam enters the well-shaped line structure to be diffracted, the focusing lens converges the vortex light beam to a focal plane, and a characteristic diffraction pattern related to a topological charge value is formed. The well-shaped line structure is composed of two groups of parallel line pairs which are mutually orthogonal, and the line width and the line spacing can be optimally designed according to the working wavelength and the light beam size. The core of the invention lies in that the well-shaped line structure is utilized to replace a traditional small-hole diaphragm, so that interfering secondary diffraction light spots in a far-field diffraction pattern are thoroughly eliminated, diffraction main light spots related to topological charges are clearly presented, and most (more than 64%) incident light energy is concentrated; and the availability and reliability of the method are improved to a great extent. The device is simple in structure and convenient to adjust, the reliable detection range of the orbital angular momentum is remarkably improved to 30 orders or above, and the device is particularly suitable for detection of weak-intensity vortex light beams and has great significance in promoting development of the free space optical communication technology.

The invention provides a high-precision multi-plane optical converter installation and adjustment method and an optical converter, and belongs to the field of optical path installation and adjustment testing. The problems that an existing method is tedious in debugging step and long in time consumption and lacks an effective compensation mechanism for the multi-degree-of-freedom coupling error are solved. The method comprises the following steps: adjusting relative positions and postures of a reflector and a phase plate according to optical feedback, so that the reflector is parallel to the phase plate; adjusting the position of the collimation single-mode optical fiber array relative to the phase plate according to the auxiliary positioning optical fiber and the phase modulation; and adjusting the position of the collimation multimode optical fiber according to the output power maximization. The method is mainly used in the free space optical communication field.

The invention provides a wireless communication connection method and converged access point equipment, and relates to the technical field of wireless communication connection, the wireless communication connection method is applied to the converged access point equipment, and the converged access point equipment comprises a radio frequency communication module, a free space optical communication module and a controller. The controller is connected with the radio frequency communication module and the free space optical communication module, and is used for executing the following steps: determining a target area, and constructing a WiFi hotspot for the target area; in response to the hotspot access request, carrying out bandwidth demand identification on the access equipment; controlling the access equipment to be connected with the radio frequency communication module in response to the fact that the identification result is the first bandwidth requirement; and in response to the identification result as the second bandwidth requirement, determining position information of the access equipment through a coarse positioning strategy, and sending the position information to the free space optical communication module, so that an optical pointing mechanism in the free space optical communication module enables the access equipment to establish connection with an optical transceiver unit based on a fine alignment strategy and the position information.

The present invention relates to an end device for optical free-space communication. Furthermore, the present invention relates to a corresponding system with corresponding optical end devices and a method for optical free-space communication.

The invention discloses a free space optical communication receiving device based on a grating array and an MZI network, solves the problem of how to quickly realize coherent combination, and belongs to the technical field of free space optical communication. The method comprises the steps that a light beam control unit adjusts incident light of a grating array according to feedback positioning information, and output of each sub-grating is divided into two parts to be sent into an MZI network; the feedback control circuit adjusts a phase modulator of a first-stage MZI in the MZI network in real time to minimize the optical power of a corresponding measurement port, extracts phase information of the first-stage MZI, presets the phase information to subsequent stages of MZIs as an initialization parameter, adjusts the corresponding phase modulator to minimize the optical power of a corresponding non-target output port, and outputs the phase information of the first-stage MZI in the MZI network. Step-by-step coherent combination of multiple paths of optical signals is realized; the light beam positioning unit obtains the output light field complex amplitude of each sub-grating through inversion according to the phase information of the first-stage MZI, calculates the center position coordinate of a light spot, and feeds back the center position coordinate of the light spot to the light beam control unit as positioning information.

Disclosed is a free space optical communication terminal comprising: a first arm interfacing a first port of a beam splitter and comprising a first component configured to emit a divergent first emitted beam and / or utilize a first received beam; a second arm interfacing the second port of the beam splitter and including a second component configured to emit a divergent second transmit beam and / or utilize a second receive beam; and a third arm interfacing the third port of the beam splitter and including a pointing unit configured to direct the first transmitted beam and / or the second transmitted beam to the target and / or to direct the first received beam and / or the second received beam received from the target. The third arm includes an optical element for collimating the transmit beam to provide a collimated transmit beam to the pointing unit and focusing the receive beam to provide a converged beam to the first / second arm. The invention further discloses a light beam guiding method and a carrying tool.

A line concentration optical communication device that communicates with a plurality of optical communication devices by free-space optical communication includes: an optical device control unit that controls an angle of a spatial optical device in each time slot on the basis of angle information and the time slot, the angle information being information indicating an angle at which each of the optical communication devices and the spatial optical device whose angle is controllable can communicate with each other, the time slot indicating a communicable time allocated to each of the optical communication devices; and an optical communication unit that performs communication with each of the optical communication devices via the spatial optical device.

This application discloses a spatial light modulator, driving method, free-space optical antenna, device, and system, relating to the field of free-space optical communication technology. The spatial light modulator includes a first substrate, a first electrode, a liquid crystal layer, a second electrode, and a second substrate. The first electrode is a planar electrode, and the second electrode includes multiple sub-electrodes spaced apart from each other. The multiple sub-electrodes are arranged sequentially from the inside to the outside around a center. When different driving voltages are applied to the first electrode and the sub-electrodes respectively, the liquid crystal material in the liquid crystal layer flips under the action of the electric field, resulting in different equivalent dielectric constants of the liquid crystal material. This allows the spatial light modulator to adjust the intensity and phase of the incident light beam to modulate different types of light beams, achieving adaptive switching of light beam types. In particular, it can achieve adaptive switching of different types of light beams in a sharp beam, improving anti-turbulence capability and enhancing the stability of the communication link.

The application relates to the technical field of free space optical communication and optical fiber transmission, and provides a transmission architecture based on a double-core optical fiber and double-channel free space optical communication, which comprises a sending terminal system, a double-core optical fiber transmission section, a double-channel FSO space section and a receiving terminal system. Two optical signals are generated at the sending terminal, coupled into two fiber cores of the double-core optical fiber through a fan-in device and transmitted in parallel, separated through a fan-out device and formed into two free space optical channels through two sets of FSO transmitting optical units respectively; two signals are received by two sets of FSO receiving optical units at the receiving terminal, respectively transmitted into two DSPs through the receiving side fan-in / fan-out and the double-core optical fiber, and based on a link quality index, channel selection backup output and / or maximum ratio combination output are executed. The application realizes parallel transmission of two parallel optical signals carried by the double-core optical fiber in the double-channel FSO space link, and improves the link stability and communication sensitivity of the receiving terminal.

The application discloses an anti-turbulence free space optical communication method based on transceiving joint optimization, through a Polar coding mode of an atmospheric turbulence channel, balance code length and code rate, ensure the overhead of coding and decoding; at the same time, a convolution enhanced Transformer model is designed at the receiving end, the learning of local features is strengthened through convolution, and the connection between phase screen pixels is established, and the conjugate phase screen is given by the model to compensate the turbulence. The application aims at the problem that the atmospheric turbulence effect disturbs the OAM light beam in the free space optical transmission system, and utilizes the joint optimization mode of the transmitting end and the receiving end to relieve the influence of the atmospheric turbulence disturbance on the free space optical communication. After the Polar coding of the transmitting end corrects the error code caused by the atmospheric turbulence, and the phase compensation of the receiving end, the coupling efficiency of the received light spot is improved, so that the mode purity of the corrected light spot image is improved, and the system error rate is reduced.

The invention provides a performance evaluation method and device for non-line-of-sight free space quantum key distribution, and belongs to the technical field of quantum communication and free space optical communication, and the method comprises the steps: constructing a three-dimensional light beam propagation model which comprises light beam drift, light beam broadening and light spot distortion caused by light beam diffraction and atmospheric turbulence; the method comprises the following steps: generating random turbulent flow phase distribution based on a sparse spectrum phase screen method, carrying out numerical simulation on a laser transmission process in combination with a step-by-step propagation algorithm, obtaining a transmissivity sample sequence in which geometric mismatch loss and a turbulent flow fading coupling effect are jointly considered under linear phase shift and secondary phase shift design, and further constructing end-to-end transmissivity probability distribution; and performing weighted evaluation on the key rate of the discrete variable and continuous variable quantum key distribution protocol by using the transmissivity probability distribution to avoid channel fluctuation distortion. The method is suitable for parameters of different turbulence intensities, wavelengths, receiving apertures and channel lengths, and can provide a basis for design and optimization of a non-line-of-sight quantum communication link.

Disclosed herein are devices, systems, and methods for selectively configuring an optical coupling network between a modem and optical head to calibrate the timing delay of the entire receive path and entire transmit path. The device includes a modem with a transmit and receive path and an optical head with an optical transmit path, an optical receive path, and a calibration path. The device includes an optical coupling network for selectively routing signals (i) through a first loopback path comprising the transmit path and the receive path; (ii) through a second loopback path comprising the transmit path, the optical transmit path, the optical receive path, and the receive path; (iii) through a third loopback path comprising the transmit path, twice the calibration path, and the receive path; and (iv) through a fourth loopback path comprising the transmit path, the calibration path, the optical receive path, and the receive path.

The invention provides a vehicle-mounted lightweight security communication system and method based on a cloud quantum key pool, and relates to the field of Internet of Vehicles information security. The method comprises the following steps: presetting the same root key in a hardware security module of a cloud terminal and a hardware security module of a vehicle-mounted terminal, obtaining a key application request of a quantum session of the vehicle-mounted terminal, and distributing a quantum session key of the communication from a cloud quantum key pool; based on the root key, encrypting a quantum session key of the communication to obtain a quantum key data packet and transmitting the quantum key data packet to the vehicle-mounted terminal; and analyzing a session key based on the quantum key data packet in the hardware security module, and encrypting the sensitive data by using the session key through a hardware accelerated symmetric encryption algorithm to obtain encrypted vehicle-mounted sensitive data, and decrypting and storing the encrypted vehicle-mounted sensitive data. The method is used in the communication process of the vehicle-mounted terminal and the cloud terminal, and solves the technical problem that the QKD is limited by a special optical fiber or precise sight distance free space optical communication in the mobile vehicle scene application.

The present disclosure provides a free space optical system for optically transmitting processed radio frequency signals through a variably refractive medium. The system may include a transmitting element configured to receive a first signal and process it to generate a time-division combined signal. The transmitting element includes an optical source to generate a beam of light, a modulator to modulate the beam of light based on the time-division combined signal, and an amplifier to amplify the modulated beam of light, which is transmitted through the variably refractive medium. A receiving element includes a photoreceiver to receive the amplified beam of light and extract a second time-division combined signal, a correction unit to correct distortion in the second time-division combined signal, a mixer to multiply the corrected signal with a predetermined frequency signal, an amplifier to amplify the multiplied signal, and an antenna to emit a radio signal generated from the amplified multiplied signal.

A communication control system includes at least one processor executing: a main communication process of carrying out communication with one or more targets through an optical fiber line; a specifying process of specifying, from among the one or more targets, a free-space optical communication target based on communication statuses in the main communication process; a sub communication process of carrying out communication with the free-space optical communication target via a free-space optical communication apparatus(es); and a selecting process of selecting, according to at least one of (i) a capacity of the communication with the free-space optical communication target in the main communication process, (ii) the communication statuses of the free-space optical communication apparatuses, and (iii) processing capacities of the free-space optical communication apparatuses, a path for free-space optical communication with the free-space optical communication target in the sub communication process.

The invention discloses a free space optical communication and sensing integrated system based on intensity modulation direct detection and time domain cross-correlation, and belongs to the field of optical communication, the system adopts an intensity modulation direct detection architecture, a transmitter uses a differential pulse position modulation signal, a DPIM signal is loaded to an optical carrier through a Mach-Zehnder modulator, and the DPIM signal is transmitted to the optical carrier through the Mach-Zehnder modulator; shaping the light beam and coupling the light beam into a free space; and the receiver couples the spatial optical signal into the optical fiber and demodulates the spatial optical signal after photoelectric conversion, so that a communication function is realized. And the transmitter receives the echo optical signal reflected by the receiver, performs analog-to-digital conversion on the echo optical signal, and then obtains the time delay of the echo signal compared with the transmitting signal by combining with a time domain cross-correlation algorithm, thereby obtaining the distance information of the two communication parties. According to the system, the radar ranging function is seamlessly integrated into a free space optical communication system, the communication and ranging functions can be simultaneously realized without additional hardware, the two functions can be simultaneously performed without mutual interference, and the system has the advantages of simple structure, low cost and high ranging precision.

A method for polarization compensation includes: (a) generating at least one beam of an electromagnetic wave; (b) sending the at least one beam through a physical medium; (c) receiving the at least one beam of an electromagnetic wave after it has traversed the physical medium; (d) measuring the intensity of the electromagnetic wave after it traverses a system of electromagnetic retarders; (e) determining the polarization of the electromagnetic wave after it traverses the system of electromagnetic retarders; (f) calculating the positions of the electromagnetic retarders to match the determined polarization of the electromagnetic wave with the polarization of the generated electromagnetic wave; and (g) compensating the effect of the physical medium on the polarization of the electromagnetic wave by setting the electromagnetic retarders according to the calculated positions.

The invention discloses a free space optical communication real-time regulation and control system based on an optical top adjusting technology, and belongs to the field of space optical communication. An AMCC transmitting module superposes an AMCC signal to a service signal to form a mixed optical signal by controlling the bias voltage of a VOA; the mixed optical signal is transmitted to a free space channel through the spatial optical lens group; the optical splitter performs communication side and control side information separate collection on the received optical signals; on a control side, an optical signal is received by an APD and converted into an electric signal, the electric signal is sent to an AMCC receiving module after being sampled by an ADC, and regulation and control information is fed back to a coherent receiver after being processed; the coherent receiver receives the regulation and control information to regulate and control the state of the board card in real time; based on the AMCC technology, the parallel processing capability of a field programmable gate array (FPGA) is utilized, and efficient regulation and control of free space optical communication are achieved.