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

Aspects of the subject disclosure may include, for example, receiving a plurality of modulated optical wavelengths generated from digital input data and unmodulated optical wavelengths. The one or more of the plurality of modulated optical wavelengths undergo an optical operation and are converted into one or more electrical signals. The optical operation increases a signal to noise ratio (SNR) of the one or more electrical signals to exceed an SNR threshold. Additionally, the one or more electrical signals are processed to produce digital output data. Other embodiments are disclosed.

The invention provides an optical fiber nutation coupling system and method based on double-optical-wedge scanning, and relates to the technical field of free space optical communication, and the system comprises a double-optical-wedge scanning system, a nutation coupling mirror and an optical fiber which are sequentially arranged along an optical path. The double-optical-wedge scanning system is provided with two optical wedges, the vertical faces are parallel and opposite, the wedge faces are opposite, and nutation scanning is carried out through reverse and / or same-direction rotation of the two optical wedges. The nutation coupling mirror is used for focusing the target light beam into a light spot to be emitted to the optical fiber; the optical power meter, the nutation controller, the double-optical-wedge scanning system driver and the double-optical-wedge scanning system are electrically connected in sequence; the optical power meter is connected with the optical fiber transmitting end and used for measuring the optical power of the target beam coupled into the optical fiber; and the nutation controller is used for resolving the rotation angles of the two optical wedges, controlling the driver of the double-optical-wedge scanning system to apply voltage, and performing linkage control on the two optical wedges. According to the invention, the rotation of the two optical wedges is dynamically optimized, so that high and stable light output coupling efficiency is ensured, and power consumption is reduced.

The invention provides an optical fiber nutation coupling method, system and device based on an electro-optical crystal, and relates to the technical field of free space optical communication, and the device mainly comprises the electro-optical crystal, a convex lens, an optical fiber, a beam splitter, an optical power meter, a controller and a driver. The electro-optical crystal comprises a first electro-optical crystal and a second electro-optical crystal which are arranged in sequence, and is arranged on a light path between an external light source and the convex lens; the optical power meter is used for detecting the power of an optical signal, converting the power into a first electric signal and inputting the first electric signal to the controller. The characteristic that the refractive index of the electro-optical crystal directionally changes along with an electric field is utilized, the three-dimensional angle error generated when laser is incident and coupled to the center of the optical fiber end face is adjusted and compensated in real time by modulating voltage, and it is ensured that signal laser emitted by an external light source is incident to the center of the optical fiber end face accurately and vertically in real time; therefore, the efficiency, quality and stability of free space laser communication are improved; the device is simple in structure, small in size and wide in application range.

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.

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.

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.

Described herein is an optical free-space communications system (100). The system (100) includes one or more inputs (102) for receiving one or more input signals (104). Each input signal (104) includes a respective data stream to be transmitted. An optical carrier signal generator module (114) is configured to generate an optical carrier signal (106). The optical carrier signal generator module includes an optical microcomb generator (116) to generate a plurality of coherent discrete, equally spaced optical frequency channels (118) and an optical spectral shaper (116) configured to selectively apply respective amplitude weightings to the optical frequency channels (118). System (100) includes a plurality of coherent modulators (108, 128) configured to modulate an optical frequency channel (118) with a respective one of the one or more input signals (104) to generate an optical transmission signal (132). A signal transmission module (130) is configured to directionally transmit the optical transmission signal (132) across a region of free-space (102) to a target location. Finally, a coherent receiver module (112) is positioned at the target location and configured to receive the transmitted optical transmission signal (132) and to decode phase and amplitude information of the one or more input signals (104) from each of the modulated optical frequency channels (118).

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 present application provides a spaceborne acquisition, tracking and pointing system and a free space optical communication link establishment method. The system comprises: an optical antenna, a laser generation module, a first detector, a light spot position determination module, a first tracking controller, and a first tracking execution mechanism. During terminal link establishment, a first terminal traverses scan points in an initial scan acquisition zone, and emits a first optical beam on the basis of the pointing direction of the currently traversed scan points. When a first feedback optical beam transmitted by a second terminal is received, the first terminal adjusts the boresight direction of the optical antenna. The first terminal emits a second optical beam by means of the optical antenna and receives a second feedback optical beam emitted by the second terminal in response to the second optical beam. When the second feedback optical beam is received, the first terminal emits a third optical beam by means of the optical antenna, so that the second terminal performs tracking processing in response to the third optical beam.

The invention provides a liquid crystal optical phased array imaging system and a design method thereof, and belongs to the technical field of liquid crystal optical phased arrays. The system comprises a camera, a lens, a beam splitter prism, a liquid crystal spatial light modulator, a super lens and a computer, and is suitable for a visible light band. Non-mechanical light beam deflection is achieved through the liquid crystal spatial light modulator, angle amplification and dispersion compensation functions are achieved in combination with the super lens, and the problems that a traditional mechanical light beam deflection technology is large in size and short in service life are solved, and the problems that an existing liquid crystal optical phased array is small in angle range and imaging aliasing is caused by dispersion are solved; the superlens adopts a three-layer nanostructure unit stacking design, the upper layer is a dispersion compensation structure, the lower layer is an angle amplification structure, and large-angle imaging and efficient spectrum utilization are realized through phase modulation; the invention has the advantages of compact structure, small volume, low cost, high stability and the like, and is suitable for the fields of laser radar, space optical communication, infrared tracking and the like.

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 present disclosure provides a free space optical communication system comprising a superluminescent light emitting diode (SLED) with an ultrashort coherence length configured to generate a broadband beam of light, a modulator configured to modulate the broadband beam of light to encode data and generate a modulated beam of light, a semiconductor optical amplifier (SOA) configured to amplify the modulated beam of light to generate an amplified beam of light, wherein the SOA has a bandwidth of at least 25, 50, or 100 nanometers, and an output configured to transmit the amplified beam of light through a variably refractive medium. The system enables high-bandwidth optical communication with improved performance in atmospheric turbulence.

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.

The tilt aberration pre-correction method based on the free space optical communication receiving end comprises the following steps: S1, capturing continuous six frames of speckle images through a CCD (Charge Coupled Device) camera, and converting the continuous six frames of speckle images into a centroid coordinate sequence by utilizing a Gray Scale Centroid module; s2, inputting the centroid coordinate sequence into an LSTM module, and obtaining speckle centroid coordinate sequence change characteristics on a continuous time domain; s3, centroid coordinate feature information predicted by the LSTM module is mapped back to a physical coordinate system through a full connection layer, the exact position of the speckle centroid at the future moment is determined, a control signal is generated to drive the optical fiber end face to deviate, and the coupling efficiency is improved; and S4, building a loop simulation system based on the spatial light modulator for testing, and verifying the effective performance under the simulated atmospheric turbulence condition. According to the invention, accurate prediction and pre-correction of the speckle centroid position at the future moment are realized, and the coupling efficiency and the signal stability of the free space optical communication receiving end under the complex atmospheric condition are improved.

An optical system for transmitting a beam of light through a variably refractive medium includes an optical source configured to generate a first beam of light, a modulator system, and an amplifier. The modulator system includes a driver configured to generate a driver signal and at least one modulator. The at least one modulator is configured to receive the driver signal and the first beam of light, and time slice and encode data on the first beam of light to generate a second beam of light. An optical spectrum of the first beam of light is matched to a wavelength range of the at least one modulator. The amplifier is configured to amplify the second beam of light to generate a third beam of light. The optical system transmits the third beam of light through a variably refractive medium.

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 present invention discloses a wavelength-division multiplexing multi-user optical wireless communication system based on a spatial light modulator. Multi-wavelength signals from a transmitting end enter free space through a multimode optical fiber and a collimating lens, and after being expanded by an achromatic lens system, are irradiated on the spatial light modulator. After being modulated by the multi-wavelength hologram displayed on the spatial light modulator, optical signals of different wavelengths are split and deflected, and focused on corresponding receivers, realizing multi-channel signal transmission. The present invention solves the problem in traditional free-space optical communication that only point-to-point fixed transmission is supported, and multi-user and mobile users are not supported. Operations such as switching between users and multi-user power allocation can be performed, and it has the advantages of strong flexibility and easy deployment, and has good application prospects in free-space optical wireless communication systems.

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.

Aspects of the present disclosure relate to adaptive coding of digital communications, such as for a free-space optical channel. Some implementations can transmit, via a first transceiver over a communications channel, a first series of data packets to a second transceiver. The first transceiver can receive a second series of data packets from the second transceiver, and an adaptive coder can analyze the second series of data packets to detect transmission conditions of the communications channel. The adaptive coder can execute one or more proactive actions based on the detected transmission conditions, such as sending error correction information for the first series of data packets and / or modifying one or more future transmission characteristics, and can do so before information regarding the reception of the first series of data packets is received from the second transceiver.

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.

Aspects of the present disclosure relate to adaptive coding of digital communications, such as for a free-space optical channel. Some implementations can transmit, via a first transceiver over a communications channel, a first series of data packets to a second transceiver. The first transceiver can receive a second series of data packets from the second transceiver, and an adaptive coder can analyze the second series of data packets to detect transmission conditions of the communications channel. The adaptive coder can execute one or more proactive actions based on the detected transmission conditions, such as sending error correction information for the first series of data packets and / or modifying one or more future transmission characteristics, and can do so before information regarding the reception of the first series of data packets is received from the second transceiver.

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.