3930results about "Electromagnetic receivers" patented technology

The invention relates to a light receiving end, which is characterized in that an array lens for coupling emergent light of each channel of a 45-degree optical fiber array into a corresponding channel of an array detector chip is arranged between a 45-degree total reflection surface of a V-shaped groove in the 45-degree optical fiber array and the array detector chip, and the side surface of the array lens is fixed with the side surface of a cover plate in the 45-degree optical fiber array in a bonding manner. The invention discloses an optical receiving end coupling method. The method comprises the following steps of: aligning each channel of a 45-degree optical fiber array with each channel of an array detector chip one by one in an active coupling manner; the array lens is coupled between the 45-degree total reflection surface of the V-shaped groove in the 45-degree optical fiber array and the array detector chip in an active coupling manner, so that light emitted from each channel of the 45-degree optical fiber array is coupled into the corresponding channel of the array detector chip, and when the optimal coupling position is reached, glue dispensing is performed, and the light emitted from each channel of the 45-degree optical fiber array is obtained. And the side surface of the array lens is fixed with the side surface of the cover plate in the 45-degree optical fiber array. The beneficial effects are that the optical receiving end is optimal in performance, highest in yield and low in cost.

Accordingly, there are disclosed herein receivers and receiving methods that provide a graceful transition from PAM2 to PAM4 signaling. One illustrative method includes: negotiating a link speed having PAM4 signaling; performing adaption of at least one gain or filter coefficient during PAM2 signaling; switching to PAM4 detection before receiving PAM4 signaling; disabling said adaptation before said switching to PAM4 detection; detecting PAM4 signaling using at least one statistic of detected PAM4 symbols; and enabling said adaptation after PAM4 signaling is detected. Another illustrative method includes: negotiating a link speed having PAM4 signaling; adapting at least one of gain and filter coefficients during PAM2 signaling; monitoring for a change in at least one signal characteristic while performing PAM2 detection; and transitioning to PAM4 detection after detecting said change.

According to the optical carrier microwave stable transmission system based on the temperature control optical fiber delay line provided by the invention, accurate reverse compensation is carried out on delay jitter change through the delay compensation module, and excellent delay consistency is shown in ultra-wideband signal transmission; the defect that compensation devices such as a traditional piezoelectric ceramic optical fiber stretcher, an optical phase shifter, a cascade multi-stage optical switch and a motor space optical delay line cannot meet the requirements of large range, high precision, quick response and wide frequency spectrum compensation capability at the same time is overcome; that is to say, the link delay compensation scheme in the transmission system has large-range, high-precision, quick-response and wide-spectrum compensation capabilities, and is particularly suitable for optical fiber transmission links with high stability and consistency requirements on ultra-wideband signal transmission.

The invention discloses an anti-turbulence free space optical communication method based on receiving and transmitting joint optimization, which balances the code length and the code rate through a Polar coding mode of an atmospheric turbulence channel, and ensures the coding and decoding overhead; meanwhile, a Transform model based on convolution enhancement is designed at a receiving end, learning of local features is enhanced through convolution, the relation between phase screen pixels is established, and a conjugate phase screen is given by the model for turbulence compensation. In order to solve the problem that in a free space optical transmission system, the atmospheric turbulence effect interferes with an OAM light beam, the influence of atmospheric turbulence interference on free space optical communication is relieved in a mode of joint optimization of the receiving end and the transmitting end. Error codes caused by atmospheric turbulence are corrected through Polar coding of the transmitting end, and the coupling efficiency of receiving light spots is improved after phase compensation of the receiving end, so that the mode purity obtained by corrected light spot images is improved, and the error rate of the system is reduced.

A redundancy link includes a first optical splitter and a second optical splitter. The first optical splitter includes (i) a first hub-side port that optically couples to a first optical line terminal, a first hub-side failover-mode port, (iii) a first plurality of node-side splitter-ports each optically coupled to the first hub-side port and the first hub-side failover-mode port, (iii) a first failover-mode port coupled to the first hub-side port. The second optical splitter includes (i) a second hub-side port that optically couples to a second optical line terminal, a second hub-side failover-mode port optically coupled to the first failover-mode port, (iii) a second plurality of node-side splitter-ports each optically coupled to the second hub-side port and the second hub-side failover-mode port, (iii) a second failover-mode port coupled to the second hub-side port.

The invention provides a method for reducing light source phase noise in a double-field quantum key distribution system, which combines an optical phase-locked loop (OPLL) and a proportional integral (PI) control technology, and comprises the following steps of: firstly, performing beat frequency on laser signals of light source ends Alice and Bob, and realizing frequency locking and phase synchronization of a laser through the OPLL; on the basis, the system introduces frequency deviation through an acousto-optic modulator (AOM) to ensure the stability of a beat frequency signal. Further, the system couples the optical signals after frequency beating through an optical beam splitter, and detects the power of the coupled optical signals. The detected power value is transmitted to the FPGA control module to serve as an input parameter of PI control, a proportionality coefficient and an integral coefficient are adjusted in real time, a feedback control signal is generated and used for dynamically adjusting a front phase modulator of a receiving end Bob, and therefore the phase noise of a light source end is effectively reduced.

The invention relates to the technical field of satellite laser communication, and discloses a laser communication double-end on-orbit calibration system and method, and the system comprises an A end and a B end which are in communication connection and have the same structure; the end B is a second laser communication terminal; the A end is a first laser communication terminal which comprises a main light path, and a transmitting branch, a receiving branch, a tracking branch and a calibration branch which are connected with the main light path; the main light path is composed of an A-end optical antenna, an A-end reflex reflector, an A-end fine tracking galvanometer, an A-end first spectroscope, an A-end second spectroscope, an A-end third spectroscope and an A-end emission galvanometer which are connected in sequence; the transmitting branch is connected with the A-end transmitting galvanometer; the receiving branch is connected with the A-end third spectroscope; the calibration branch is connected with the A-end second spectroscope; and the tracking branch is connected with the A-end first spectroscope. According to the invention, on-orbit receiving and transmitting coaxial calibration is carried out, calibration is carried out without the help of a ground end, and the efficiency is improved.

The invention relates to laser communication, in particular to a non-rotating type space laser communication system and method based on a liquid crystal phase regulation and control device, and aims to overcome the defects that in the prior art, a liquid crystal spatial light modulator is small in deflection angle and small in transmitting and receiving aperture, and the requirements for the capturing and tracking range and aperture of space laser communication are difficult to meet. The non-rotation type space laser communication system based on the liquid crystal phase regulation and control device comprises an adjustable phase delayer, a liquid crystal polarization grating module, a beam shrinking module, a liquid crystal space light modulator, a fine tracking galvanometer, a light splitting module, a coarse tracking module, a fine tracking module, a communication module and a data processing module, according to the communication method based on the system, light beam deflection is carried out through the adjustable phase delayer, the liquid crystal polarization grating module, the liquid crystal spatial light modulator and the fine tracking galvanometer, a traditional mechanical rotary table is replaced, and high-precision adjustment is achieved.

An optical ranging system includes a coherent IQ receiver configured to receive a radio frequency (RF)-encoded optical signal, generate an in-phase (I) electrical signal and a quadrature (Q) electrical signal based on the RF-encoded optical signal; a first analog-to-digital converter (ADC) configured to convert the I electrical signal into an I digital signal; a second ADC configured to convert the Q electrical signal into a Q digital; and a processing circuit configured to generate a power signal having the target frequency by squaring the I digital signal and the Q digital signal, and summing a squared I digital signal and a squared Q digital signal. The processing circuit is configured to analyze the power signal to determine a signal phase corresponding to signal peaks associated with the target frequency, and determine a distance value based on a phase difference between the signal phase and a reference power signal.

The invention discloses a laser channel atmospheric turbulence fading real-time compensation device and method based on a galvanometer system, and the method comprises the steps: enabling an incident light beam to irradiate a transparent PCB integrated with a photodiode array after the incident light beam is focused through a convex lens, obtaining the light intensity distribution of a current light spot through the photodiode array, and transmitting the light intensity distribution to a signal processing unit; the signal processing unit coarsely adjusts the deviation direction of the light spots according to the received light intensity distribution data, and aligns the part with the strongest light intensity in the light spots to the end face of the optical fiber; and based on the roughly adjusted light spot deviation direction, the signal processing unit dynamically adjusts the deflection angle of the galvanometer by using a gradient descent method according to the power measurement value of the receiving coupling module, so that the fine adjustment of the light spot deviation direction is realized, and the receiving coupling power is maximized. The objective of receiving optical power maximization is achieved, optical design, electronic control and algorithm optimization are combined, and atmospheric turbulence compensation with high cost performance is achieved.

The invention discloses a time delay compensation control method and system for two-way communication of a repeater, particularly relates to the technical field of repeaters, and is used for solving the problem of signal time delay distortion caused by polarization mode dispersion in an optical fiber link. By using polynomial fitting and a frequency domain interpolation algorithm and combining a polarization state time delay spectrum chaos degree index and a phase high-order dynamic variable rate index, the complexity of the model is dynamically adjusted, an accurate nonlinear time delay model is generated, and the defect of nonlinear time delay modeling in a traditional method is overcome; the time delay compensation amount is reversely calculated based on the model and mapped into a phase predistortion parameter, a full-band time delay gradient compensation matrix is formed, and the time delay dispersion effect in an optical fiber link is effectively compensated through phase predistortion; therefore, the flattening correction of the broadband signal time delay is realized, the demodulation performance of the receiving end signal is improved, the communication quality of the repeater in a high-frequency and large-bandwidth scene is ensured, and the high-precision service requirement is met.

An optical communication receiver system for a mobile platform includes: a surface having an entrance aperture for entry of an optical communication signal from a remote source; an optical receiver to receive the optical communication signal through the entrance aperture; a reflective layer over at least a portion of the surface to at least partially reflect an alignment beam that is substantially coincident with the optical communication signal; a camera positioned to detect the reflected alignment beam; a processor to determine alignment information about the alignment beam relative to the entrance aperture based on the reflected alignment beam detected by the camera; and a transmitter to transmit the alignment information to the remote source to enable the remote source to center the optical communication signal in the entrance aperture.

The invention discloses a wireless optical communication alignment system and a capture alignment method thereof, and relates to the technical field of optical communication, and the method comprises the steps: a three-dimensional holder carries out the coarse alignment of an optical path between a transmitting end and a receiving end according to the direction of beacon light; an alignment device located at the top of the three-dimensional holder carries out fine alignment on the light path; the alignment device comprises a two-dimensional alignment structure, a control circuit and a device shell. The control circuit captures a light intensity feedback value of the light intensity sensor of the two-dimensional alignment structure, and adjusts an azimuth angle and a pitch angle of the optical fiber collimator of the two-dimensional alignment structure according to the light intensity feedback value so as to adjust lens orientations of the transmitting end and the receiving end; the device shell provides a supporting platform for the two-dimensional alignment structure and the control circuit and is connected with the three-dimensional holder. Coarse alignment and fine alignment are combined, accurate angle adjustment is achieved through light intensity feedback, efficient alignment of light paths of the transmitting end and the receiving end is ensured, meanwhile, the device shell provides stable support and connection, and the stability and reliability of the alignment process are guaranteed.

The invention discloses an adaptive equalization method for combined compensation of carrier frequency offset and channel linear damage. The adaptive equalization method specifically comprises the following steps: taking data subjected to matched filtering, clock synchronization, orthogonality and normalization as input signals; for an input signal, using the filter linear damage compensation weight vector and the frequency offset compensation weight coefficient to obtain output data of the filter; obtaining an expected value of filter output data, and calculating to obtain a theoretical error value of adaptive equalization; and obtaining a filter weight vector used for next adaptive equalization according to the theoretical error value. The adaptive equalization method for combined compensation of carrier frequency offset and channel linear impairment is suitable for a coherent optical transmission system, uses an adaptive equalizer to compensate signal frequency offset and channel linear impairment at the same time, does not need an additional frequency offset estimation algorithm, meets the advantages of multiple rates and multiple modulation formats, and is high in convergence speed and high in robustness. And the calculation complexity is low.

The invention provides an optical device, an optical module and an optical communication system. The optical device provided by the invention comprises a tube body, and a first receiving packaging structure, a second receiving packaging structure and a first transmitting packaging structure which are mounted on the tube body. A first light receiving chip used for receiving light of a first wave band is packaged in the first receiving packaging structure. A second light receiving chip used for receiving light of a second wave band and a third light receiving chip used for receiving light of a third wave band are packaged in the second receiving packaging structure. A first light emitting chip used for emitting light of a fourth wave band and a second light emitting chip used for emitting light of a fifth wave band are packaged in the first emitting packaging structure. The optical device provided by the invention can integrate three receiving optical paths and three transmitting optical paths at the same time, and can realize compatibility of three generations of network services so as to realize smooth upgrading of different generations of network services, so that the compatibility of an optical module and an optical communication system applying the optical device to different generations of network services can be improved.

An optical emission array includes an optical input portion configured to provide a parent laser source for the optical emission array, and an optical output portion including a plurality of child laser emitters. Each child laser emitter of the plurality of child laser emitters is injection-locked to the parent laser source. The optical emission array further includes at least two optical distribution branches (i) disposed between the optical input portion and the optical output portion, and (ii) optically connecting at least two child laser emitters of the plurality of child laser emitters, respectively, to the parent laser source.

The disclosure discloses an OAM measurement device independent quantum key distribution system based on real-time tracking compensation and method thereof, which comprises a user side Alice, a user side Bob and a measuring unit; the user side Alice and the user side Bob realize real-time monitoring and phase distortion compensation of the channel environment by using strong pulse lasers from the measuring unit; the measuring unit utilizes an M-Z interferometer formed by a Dove prism to realize the separation of odd / even orbital angular momentum order photons, and measure Bell states of the photons with orbital angular momentum; the disclosure realizes OAM measurement device independent quantum key distribution system based on real-time tracking compensation, and the user uses the orbital angular momentum state for coding, thereby having the characteristics of good stability, high code rate and strong expansibility.

The invention discloses a quantum noise stream signal transmission method and device based on odd-order constellation forming in the technical field of optical transmission communication. The method comprises the following steps: generating four-dimensional chaotic sequences X, Y, Z and W by utilizing a 4D hyperchaotic model according to an initial key; performing serial-to-parallel conversion and up-sampling on the initial key, introducing error bits into a key matrix by utilizing W, and dividing the key matrix into a first state basis matrix and a second state basis matrix; performing specificity comparison or processing on the original data by using the X to obtain first data; dividing the first data into a data matrix and an index bit matrix, and performing joint index modulation to obtain a 9QAM signal; scrambling a subcarrier and a symbol point of the 9QAM signal by using the Y and the Z to obtain a 9QAM scrambled signal; and performing quasi-quantum noise stream encryption processing on the 9QAM scrambling signal by using the first state basis matrix and the second state basis matrix to obtain a 576QAM encrypted signal, performing OFDM modulation, and transmitting the 576QAM encrypted signal in an optical fiber channel.

The invention discloses a noise suppression parameter self-adjusting optical fiber optical frequency transfer relay system, which comprises multiple stages of relay stations which are cascaded in sequence, each stage of relay station comprises a receiving end, an optical amplification end and a transmitting end which are connected in sequence, and the transmitting end of the previous stage of relay station is connected to the receiving end of the next stage of relay station, the receiving end is used for receiving an optical frequency signal from an upper-level relay station; the optical amplification end is used for carrying out coherent amplification on a received optical frequency signal, and the sending end is used for transmitting the optical frequency signal after coherent amplification to a next-stage relay station and measuring and eliminating additional phase noise in a signal transmission link. According to the optical fiber optical frequency transfer relay system, self-adjustment of noise suppression parameters can be effectively achieved, and therefore effective suppression of additional phase noise is achieved.

An optical receiver includes: a data processing circuit used to receive an optical signal carrying data information and perform a signal processing on the optical signal to obtain the data information and performance parameter (s) for indicating transmission quality of the optical signal; a memory used to dynamically buffer waveform data obtained through the signal processing of the optical signal; and a detection controller used to output a first indicating signal to the memory in a case where the at least one performance parameter satisfies a first condition. The first condition includes that the optical signal has a transmission fault and / or the transmission quality of the optical signal decreases to a first degree. The memory is further used to freeze current waveform data to obtain frozen waveform data in response to the first indicating signal, and the frozen waveform data includes waveform characteristic information of the transmission fault.

The invention discloses a variable beam divergence angle laser communication terminal and a rapid capturing method thereof, and belongs to the technical field of optical communication equipment. Comprising a main telescope, a fine tracking fast reflecting mirror, a beam splitter, an optical filter, a beam splitter, a beacon receiving lens group, a beacon detector, a signal transmitting lens group, an advanced aiming fast reflecting mirror, a signal receiving lens group, a receiving optical fiber amplifier, a multi-core optical fiber splitter, an optical switch and a transmitting optical fiber amplifier, a signal light emitting light path, a beacon light receiving light path and a signal light receiving light path are formed; the signal light emission light path provides emission light beams through different mode field optical fibers and performs shaping and variable beam divergence angle emission on the emission light by using different paths of an emission mirror group, and the signal light receiving light path is used for completing collection, shaping, coupling and light amplification on input signal light. And the beacon light receiving optical path is used for collecting, shaping and converging the input signal light, and positioning a target light spot by using an image positioning detector. According to the invention, the remote capturing efficiency can be improved.

A method for monitoring generalized optical signal-to-noise ratio (gOSNR) is provided, which is applied to monitoring of an optical signal received by a coherent receiver through a fiber link. The method includes: obtaining a first received waveform; obtaining a signal part of the first received waveform; obtaining a noise part of the first received waveform according to the signal part and the first received waveform; obtaining a first correlation between the noise part and a first template at a predetermined location on the fiber link, the first correlation indicating a signal power at the predetermined location; obtaining a second correlation between the noise part and a second template at the predetermined location on the fiber link, the second correlation indicating a signal power and noise power at the predetermined location; and obtaining gOSNR at the predetermined location according to the first correlation and the second correlation.

The invention provides a signal receiving device, a signal transmitting device and an optical fiber sensing device, relates to the technical field of optical fiber sensing, and is used for solving the problems that the requirement for equipment is high when an existing optical fiber sensing device detects Rayleigh scattering and Brillouin scattering at the same time and the like. The signal receiving device comprises a coherent receiver, a radio frequency analog-to-digital conversion unit and a frequency band calculation unit, the coherent receiver is used for obtaining four electric signals with orthogonal phases according to the local oscillation light and the signal light, and the radio frequency analog-to-digital conversion unit converts the four electric signals to obtain two digital signals in a first polarization state and two digital signals in a second polarization state; the frequency band calculation unit is used for calculating the frequency spectrum of the signal light according to the two paths of digital signals of the first polarization state of the signal light and the two paths of digital signals of the second polarization state of the signal light, and the frequency spectrum comprises a phi OTDR signal located at the positive frequency and a BOTDR signal located at the negative frequency.

Methods and apparatus for conveying directionality and distance information from a transmitter to a receiver within the coordinate system of the transmitter. Conveying the directionality and distance information to the receiver may, for example, reduce computational loads at the receiver. The signal from the transmitter may include information for rendering digital content and information indicating the direction and distance of the transmitter, and the receiver may render the digital content using the direction and distance to reduce processing at the receiver. Alternatively, the signal may include pre-rendered content based on the direction to further reduce processing at the receiver.

Coherent wavelength division multiplexing is provided using frequency comb sources for both the transmitter and the local oscillator (LO) in the receiver. The local oscillator is made phase coherent with the received multifrequency optical signal using two analog control loops. One of the control loops locks an optical frequency of the local oscillator to an optical frequency of the received frequency comb. The other control loop locks a microwave frequency of the local oscillator (i. e. LO the comb spacing) to the comb spacing of the received frequency comb. As a result, coherent detection is enabled in all channels with just two analog control loops. Control signals for the two loops can be derived from two of the received channels individually (asymmetric carrier recovery), or they can be derived from sum and difference signals from two of the received channels (symmetric carrier recovery).

A method is disclosed for use in detecting a pulsed optical beam when the pulsed optical beam is transmitted through a scattering medium, wherein the pulsed optical beam comprises a plurality of optical pulses and the method comprises using a plurality of photodetectors of a photodetector array to detect light which is scattered progressively from the same optical pulse as the optical pulse propagates through a plurality of regions of the scattering medium and which is then received progressively on different photodetectors of the photodetector array. The method may be used in particular, though not exclusively, for non-line-of-sight free-space optical communications. An optical receiver for use in detecting the pulsed optical beam and an associated optical system are also disclosed.

The embodiment of the invention discloses a signal processing method and a related device. The signal processing method can be applied to an optical communication scene. The method provided by the embodiment of the invention comprises the following steps: a sending end upsets the polarity of a part of symbols in a first modulation signal to obtain a second modulation signal, so that the absolute value of the sum of the values of all the symbols in the second modulation signal is smaller than the absolute value of the sum of the values of all the symbols in the first modulation signal. Therefore, the suppression of the low-frequency part power in the second modulation signal is realized, and the receiving end can carry out direct current removal processing on the signal to resist the influence of low-frequency noise in a channel on the transmission performance. And the receiving end carries out inverse transformation of power spectrum adjustment on the received signal according to the identification information, so that the original signal before the sending end carries out the power spectrum adjustment is recovered and obtained.

An optical receiver comprises a monolithically integrated pin photodiode (PIN) and transimpedance amplifier (TIA). The TIA comprises InP heterojunction bipolar transistors (HBT) fabricated from a first plurality of layers of an epitaxial layer stack grown on a SI:InP substrate; the PIN is fabricated from a second plurality of layers of the epitaxial layer stack. The p-contact of the PIN is directly connected to the input of the TIA to reduce PIN capacitance CPIN. The TIA capacitance CTIA may be matched to CPIN. Device parameters comprising: a thickness of the absorption layer, window area, and an optional mirror thickness of the PIN; device capacitance CPIN+CTIA; and feedback resistance RF of the TIA; are optimized to performance specifications comprising a specified sensitivity and responsivity at an operational wavelength. This design approach enables cost-effective fabrication an integrated PIN-TIA, for applications such as a 1577 nm receiver for an ONU for 10G-PON.

A dual-polarization (DP) intensity-modulated direct detection (IMDD) receiver includes an input port configured to receive input light; an optical polarization splitter configured to split the input light into a pair of optical transmission paths; a pair of photodetectors including (i) a first photodetector configured to detect light at a first carrier frequency and output an electrical signal into a first electrical transmission path, (ii) a second photodetector configured to detect light at a second carrier frequency and output an electrical signal into a second electrical transmission path, wherein the first carrier frequency and the second carrier frequency are separated by a frequency difference; and an electrical 2×2 multi-input-multi-output (MIMO) polarization demultiplexer configured to input the first electrical transmission path and the second electrical transmission path and perform electrical 2×2 MIMO polarization demultiplexing to output a first demultiplexed signal and a second demultiplexed signal.

The invention discloses an integrated optical diversity receiving device, solves the problem of high power consumption when the influence caused by phase distortion and light beam pointing error is corrected in the existing free space optical communication, and belongs to the field of optical communication. The method comprises the steps that free space light focused by a lens is received by a multimode / few-mode optical fiber; the multi-mode light beams received by the multimode / few-mode optical fiber enter the photon lantern; the photon lantern is coupled to the single-mode fiber array after mode demultiplexing; each light beam in the single-mode fiber array enters a polarization beam splitting rotary combiner through an edge coupler; the polarization beam splitting rotation combiner performs transverse electric wave (TE) and transverse magnetic wave (TM) mode separation on the entered light beam, then rotates the separated TM polarization state light to a TE polarization state, combines the rotated TE polarization state light and the separated TE polarization state light, and then enters the MZI network; the MZI network is used for realizing optical coherent beam combination; a control circuit controls the merging of the light beams in the MZI network.