139results about "Photonic quantum communication" patented technology

The application relates to a photonic tensor calculation method, a photonic tensor core, a computer device and a storage medium. The method comprises the following steps: generating a multi-wavelength optical signal, modulating optical signals of each wavelength in the multi-wavelength optical signal through a first loopback arrayed waveguide grating, and multiplexing to obtain a first optical signal with multiple wavelengths; splitting each first optical signal to obtain a plurality of first optical signal copies, and modulating optical signals of each wavelength in a single first optical signal copy through a plurality of second loopback arrayed waveguide gratings, and multiplexing to obtain a second optical signal; and photoelectrically converting each second optical signal to obtain a tensor calculation result. The method can improve the photonic tensor calculation accuracy and scalability.

The application discloses a Stokes parameter encoder, which comprises a fiber optical circulator and an optical path round trip path; a polarization maintaining fiber Faraday rotator is arranged on the optical path round trip path to rotate the polarization of light by 45 degrees; the fiber optical circulator is a polarization maintaining fiber optical circulator; the fiber optical polarization beam splitter is a polarization maintaining fiber optical polarization beam splitter; the delay fiber is a polarization maintaining delay fiber; and the fiber optical phase modulator is a polarization maintaining fiber optical phase modulator. The application further discloses a parameter encoding method of the encoder. The above technical scheme can perfectly offset the rotation angle deviation problem caused by the device, can guarantee the stability of the rotation angle regardless of the angle deviation of the device, is easy to realize the driving circuit, is easy to integrate and small in size due to the pure fiber structure, and can realize the continuous variable quantum key distribution of the complete GG02 protocol based on the Stokes encoder.

An illustrative transmitter can achieve improvement in SN ratio and stability of the signal output under control at the transmission side, even in the case of an optical transmission line having the propagation characteristics susceptible to environmental changes. The transmitter includes: an optical transmission section configured to generate weak signal light and reference light from a transmission light pulse, and transmit the signal light and the reference light to the optical transmission line; and a controller configured to modulate pulse intensity and pulse width of the transmission light pulse according to a transmission line state of probe light having propagated through the optical transmission line.

Atomic object confinement devices including RF bus and systems including atomic object confinement devices including RF bus are provided. An exemplary atomic object confinement device includes RF rail electrodes and an RF bus electrode. The RF rail electrodes form a periodic array of confinement segments within a central region of the atomic object confinement device, and the RF bus electrode is disposed in a peripheral region disposed about the central region. The RF rail electrodes and the RF bus electrode are configured to produce an array of substantially periodic trapping regions when an oscillating voltage signal is applied to the RF rail electrodes and the RF bus electrode.

A signal transmission method and an apparatus are disclosed. In this method, a first communication apparatus generates a full-wave radio frequency electrical signal, and converts the full-wave radio frequency electrical signal into a half-wave radio frequency optical signal. The half-wave radio frequency optical signal is a radio frequency optical signal having a positive half-amplitude or a negative half-amplitude of the full-wave radio frequency electrical signal. The first communication apparatus sends the half-wave radio frequency optical signal. A second communication apparatus receives the half-wave radio frequency optical signal, and converts the half-wave radio frequency optical signal into the full-wave radio frequency electrical signal. It can be learned that, compared with a radio frequency optical signal having a full amplitude of the full-wave radio frequency electrical signal, average optical power of the half-wave radio frequency optical signal is lower, reducing transmit optical power between the first communication apparatus and the second communication apparatus. This helps reduce power consumption of an optical component. When an optical signal is transmitted between the first communication apparatus and the second communication apparatus through an optical fiber, the reduction of the transmit optical power further helps reduce a non-linear effect of optical fiber transmission, to reduce signal distortion caused by the non-linear effect of the optical fiber transmission.

A transmitting device (2a) for providing a coded optical output signal (L3), in particular for quantum key exchange, a transmitting station (7a), in particular a satellite (9b), with a corresponding transmitting device (2a), and a communication system (1) for providing coded optical communication are proposed, wherein the transmitting device (2a) comprises a light source (110) configured as a double pulse source for providing an optical input signal (L0) comprising double pulse pairs (D) and / or single pulses (P), and a modulation unit (120) for modulating the phase components of the polarization components of the optical input signal (L0) during encoding of the optical output signal (L3), and wherein the modulation unit (120) is configured to optionally enable polarization-, phase-based encoding (X, Y) and / or time-bin encoding of the pulses (P) of the optical output signal (L3).

This invention discloses a bidirectional continuous-variable quantum key distribution method and system based on frequency division duplexing in a single-transceiver ring network. The method is based on a monolithically integrated silicon photonics transceiver chip. By pre-setting optical carrier frequency offsets for the forward and reverse links, it isolates the quantum signal from Rayleigh backscattering noise in the fiber in the frequency domain. The transmitting end generates a broadband waveform containing quantum signals and pilot signals, which is transmitted bidirectionally through a single optical fiber. The receiving end uses a laser source from the same chip as the local oscillator for coherent heterodyne detection. A digital signal processing module performs orthogonalization correction, phase recovery, and matched filtering to suppress noise and extract the quantum signal to generate a secure key. This invention solves the problems of inflexible networking, low fiber utilization, and severe scattering noise interference in bidirectional transmission over a single fiber caused by the separation of the transmitting and receiving ends in integrated continuous-variable quantum key distribution systems. It provides a low-cost and highly flexible solution for metropolitan quantum ring networks.

The application aims to provide a solid-state quantum communication receiver based on diamond nitrogen vacancy color center, and belongs to the technical field of quantum communication. The communication receiver realizes high-multiple amplification of a magnetic field signal by designing a logarithmic-periodic antenna, solves the problem of reduced measurement sensitivity caused by the fact that an alternating magnetic field is only 1 / 377 of an alternating electric field in traditional measurement, realizes simultaneous receiving of phase and field strength by means of mixing technology of the diamond nitrogen vacancy color center, realizes high-sensitivity receiving of an electric field signal by means of the characteristics that the electric field and the magnetic field coexist in space, and realizes inversion of the entire modulated signal based on the received signal.

A system and method for implementing and utilizing embedded quantum random number generator (QRNG)-based devices are provided. [Solution] An optical device configured for use in quantum random number generation may have an integrated structure comprising at least a light source configured to emit a light beam, a photodetector configured to detect light based on a detection criterion, and a polarizer positioned between the light source and the photodetector. The light source, photodetector, and polarizer are directly integrated or embedded in the integrated structure. The polarizer is configured to process light based on a polarization criterion, including allowing or discarding light having a specific polarization. The optical device is configured for use in facilitating or enabling quantum random number generation based on the detection of a light beam by a detector based on a detection criterion.

This invention discloses a quantum-state-controlled IoT wireless communication anti-interference transmission method, relating to the field of IoT wireless communication technology, comprising the following steps: IoT nodes collect and fuse multi-dimensional real-time data on power consumption, task priority, and channel interference; generate a control coding strategy based on a quantum state complexity-energy consumption model, and enable lightweight encryption when power consumption is low; an edge server predicts optimal parameters, and the node completes quantum state generation, encoding, and transmission accordingly; finally, transmission performance data is collected, and parameters are updated through evaluation and optimization algorithms to form a closed-loop control across the entire link; this invention intelligently matches the quantum state control level and coding combination through multi-dimensional data collection and dynamic fusion, and enables quantum random number encryption when power consumption is low, thereby improving communication reliability. By utilizing a hybrid prediction model and closed-loop optimization of the edge server, the control parameters are accurately predicted and the model is continuously iterated, taking into account key indicators and meeting the high reliability and low power consumption communication requirements of the IoT.

This application provides a quantum fusion key encryption method, device, and system based on PON networks, applied in the field of encryption technology. By obtaining a quantum key from a quantum cryptography service platform and XORing it with a random key generated by the AES standard algorithm, an AES quantum fusion key with high unpredictability and high complexity is generated. This retains the algorithm compatibility of AES while significantly increasing the key complexity. The key is then synchronized to the central office equipment to ensure key consistency at both ends. Finally, the standard AES algorithm is directly called, and the AES quantum fusion key is used to encrypt or decrypt PON data frames. Thus, the security level of PON network encryption can be effectively improved without modifying the AES core.

The application discloses a network time slot and key cooperative scheduling method and system fused with QKD and PQC, belongs to the technical field of quantum key distribution, and comprises the following steps: S1, constructing a unified resource state library; S2, designing a strategy engine and initializing parameters; S3, receiving a service request and performing preliminary screening; S4, performing time slot-key distribution according to service requirements; S5, monitoring real-time states, returning to step S3 if there is no exception, and performing step S6 if there is an exception; and S6, performing fault processing and optimizing resource distribution. The application adopts QKD+PQC fused keys in the technical field, not only uses QKD keys for encryption, but also considers using PQC encryption algorithms for service encryption, combines two different key resources with OTN time slots, fully and reasonably schedules and distributes key resources while ensuring uninterrupted service encryption, and maximally guarantees the security of an operator OTN network.

The invention relates to a receiving apparatus (RX) in a quantum optical communication system (1).

Methods, systems and apparatus for implementing a secure quantum swap operation on a first and second qubit. In one aspect a method includes establishing, by a first party and with a second party, an agreement to use a secure swap protocol; performing the quantum swap operation, comprising, for each two-qubit gate included in the quantum swap operation: performing, by the first party and according to the secure swap protocol, a respective preceding quantum gate cipher on the first qubit; performing, by the first party and the second party, the two-qubit gate on the first qubit and the second qubit; and performing, by the first party and according to the secure swap protocol, a respective succeeding quantum gate cipher on the first qubit. The preceding and succeeding quantum gate ciphers comprise computational bases that anti-commute with a computational basis of the two-qubit gate across a second axis of the Bloch sphere.

The purpose of the present disclosure is to transmit or receive data in a quantum communication system, and a method therefor may comprise the steps of: acquiring system information; performing a random access procedure on the basis of the system information; transmitting, to a second device, a first signal for measurement; receiving information related to a first measurement result from the second device; generating a data signal by performing data encoding on the basis of a quantum teleportation operator determined on the basis of the first measurement result; and transmitting the data signal to the second device.

This invention discloses a high-capacity teleportation method based on three-dimensional electron-photon entangled states: Step 1: Alice prepares electron-photon entangled pairs and splits them into photon sequences. P and electronic sequence E Step 2: Alice sequences the electrons. E Send to Bob; Step 3: Alice selects the unitary operation and applies it to the photon sequence. P Bob obtains the photon sequence and the electron sequence; Step 4: Bob uses phase-shifting electron holography to perform interferometric measurements on the electron sequence and acquires an interference hologram; Step 5: Bob informs Alice to measure the photon sequence and provides her with the photon number, state, and position; Step 6: Bob performs phase reconstruction on the interference hologram and decodes the original information. This invention, through a rationally designed coding phase interval and by controlling the extremely low decoding failure rate with a confidence coefficient, surpasses the theoretical limit of 2log23 bits for the coding capacity of traditional 3D photon Bell state ultra-dense coding, achieving a theoretical coding capacity of 8.5 bits with a bit error rate of 0.27%.

Transmitters, receivers, systems and methods for compensating for polarization drift caused by a communications channel are provided. One or more polarization reference signal(s) or sets of polarization reference signals may be transmitted in combination with a polarized communications signal. The combination may be via wavelength or time multiplexing. Polarization measurements of the one or more polarization reference signals or sets of polarization reference signals and subsequent heterodyne detections thereof may be used for compensation of the polarization drift of the combined signals which are received. The polarization compensation may be for a State of Polarization (SOP) of a polarized communications signal such as any one polarization basis. The polarization compensation may be for complete polarization channel compensation such as for three different polarization basis which are mutually unbiased.

This invention belongs to the field of wireless optical communication technology, specifically a sub-Poisson multi-user photon counting communication system and its design method based on the WMSE criterion. The invention includes constructing a multi-user, multi-input, single-output photon counting communication model and introducing a sub-Poisson photon counting reception mechanism; deriving the mean square error expression for each user under sub-Poisson conditions, introducing the reciprocal of the noise variance as a weighting coefficient, and constructing a noise-aware weighted MSE optimization objective; designing a multi-user precoding scheme using a continuous convex approximation method, and minimizing the system's weighted error and optimizing performance by updating the weighting coefficients in the outer layer and optimizing the precoding matrix in the inner layer. This invention can effectively suppress the impact of heteroscedastic noise on system performance under sub-Poisson noise conditions, significantly reduce the system's average bit error rate, and improve the transmission performance and noise immunity of the multi-user photon counting communication system; it can be applied to scenarios such as UAV networks, satellite-to-ground optical communication, and secure optical transmission.

The application provides a frequency stabilized laser device and a quantum communication system, and relates to the technical field of lasers.The frequency stabilized laser device comprises: a first distributed feedback laser for generating a first laser; a second distributed feedback laser for generating a second laser; an inner closed loop for cavity mode locking of the first distributed feedback laser and the second distributed feedback laser respectively, so as to suppress noise and cavity length disturbance and complete short-term stable regulation; and an outer closed loop for beat frequency processing of the first laser and the second laser according to a reference frequency, so that the frequencies of the first laser and the second laser remain stable, the long-term thermal drift of the first distributed feedback laser and the second distributed feedback laser is suppressed, and short-term and long-term stability is unified.The application can solve the technical problems that the existing laser cannot simultaneously realize short-term low noise and long-term low drift, the stable cavity effect is poor, and frequency difference monitoring is difficult, and realizes the unification of short-term stability and long-term stability of the laser signal.

The application provides a fluorescence attack detection method and device for a quantum communication system and the quantum communication system. The fluorescence attack detection device automatically collects count information before and after a test light signal is input into a to-be-detected device through various modules in the fluorescence attack detection device. Based on the background count information, peak count information, test count information and reference port reflection position obtained through detection, fluorescence attack detection of the to-be-detected device, fluorescence leakage rate calculation and security evaluation are realized. The application realizes forward detection and verification of fluorescence attack, and can demonstrate fluorescence attack based on actual needs. Through system analysis of multiple parameters, the security of the to-be-detected device can be more comprehensively reflected, and the actual security of the quantum communication system is effectively improved.

Techniques for exposing entangled quantum states is disclosed, comprising the following steps: • storing entangled quantum states in a quantum memory at a network node; • storing metadata associated with the quantum states in a classical metadata memory, wherein the metadata includes a physical storage address, a time slot identifier and a logical identifier; • requesting the entangled quantum states from the quantum memory via a classical API; • exposing the entangled quantum states to users of a quantum communication protocol over a quantum communication channel.

This invention discloses an attack-resistant quantum key distribution method and system based on real-time statistical monitoring of light sources, belonging to the field of quantum communication. This invention utilizes the second-order correlation function g of a subposon solid-state single-photon source. (2) (0) As a "security fingerprint," it achieves high-sensitivity, millisecond-level detection of photon number splitting (PNS) attacks by monitoring its statistical offset during communication in real time. In a secure state where no attack is confirmed, the system activates an enhanced mode, legally incorporating the key contribution of two-photon pulses within the framework of information-theoretic security through a security weight factor dynamically determined by the monitoring results, thereby overcoming the conservative limitation of unconditionally eliminating multi-photon pulses in the traditional GLLP framework. This invention significantly reduces the hardware requirements for the purity of single-photon sources, enabling efficient utilization of medium-purity light sources; simultaneously, in high-loss scenarios, the key rate can be increased by more than three orders of magnitude compared to existing technologies, significantly extending the relay-free secure transmission distance of QKD.

A system and method for distributing quantum entanglement using optically protected fiber optical paths is described. In some embodiments, multiple optical paths are used to connect a source site to a receiver site. Quantum entangled particles are transmitted from the source site to the receiver site using a first one of the multiple optical paths and related service channel information is transmitted from the source site to the receiver site using a second one of the multiple optical paths. In response to a failure of either the first or second optical path, an entanglement distribution controller automatically updates the routing such that the service channel information and the quantum entangled particles are routed concurrently on a remaining one of the first or second optical path.

A multiplexed communication system that can improve wavelength utilization efficiency and simplify the structure in two-way WDM communication is provided. The system includes an optical transmission line 31 for wavelength-multiplexed transmission in a first direction from a communication device 10 to a communication device 20; and an optical transmission line 32 for wavelength-multiplexed transmission in a second direction opposite to the first direction. The communication device 10 performs: first transmission in the first direction; and first two-way communication between the communication devices 10 and 20 in relation to the first transmission. The communication device 20 performs: second transmission in the second direction; and second two-way communication between the communication devices 10 and 20 related to the second transmission. The first transmission and the second transmission use communication light of a first wavelength λQ on the optical transmission lines 31 and 32. The first and second two-way communications use communication light of a wavelength λ1c, λ2c different from the first wavelength λQ on the optical transmission lines 31 and 32.

A method of determining an offset between a first time reference and a second time reference is disclosed. The method comprises obtaining (102) information relating to a detection time at a first node of a first photon of a first pair of photons, and a detection 5time at a second node of a second photon of the first pair of photons; obtaining (104) information relating to a detection time at the first node of a first photon of a second pair of photons, and a detection time at the first node of a third photon; and determining (106) an offset between a first time reference at the first node and a second time reference at the second node based on the obtained information. An apparatus, a computer program 0and a computer program product for determining an offset between a first time reference and a second time reference are disclosed.

A quantum node includes one or more communication qubits, one or more interior qubits coupled to the one or more communication qubits with interior tunable couplers, a communication tunable coupler coupled to each of the one or more communication qubits, and a communication resonator coupled to each of the communication tunable couplers. In addition, a distributed quantum computing system includes two or more quantum nodes, and one or more coaxial cables or coplanar waveguides connecting the two or more quantum nodes together using at least one of the communication resonators of the two or more quantum nodes. Entanglement and fabrication methods of the quantum nodes are also described.

Systems and methods for generating an entangled pair of bichromatic photons are described. The system includes an atomic vapor cell containing atoms of an atomic species located within beam paths of a first and second laser beam. The first and second laser beams are tuned to first and second wavelengths that are resonant with first and second atomic transitions of the atomic species such that the first and second laser beams cause a four-wave mixing process within the atomic vapor cell. As a result of the four-wave mixing process, entangled photon pairs having a third and fourth wavelength are generated and output from the atomic vapor cell. The first and second wavelengths may be selected to create electromagnetically-induced transparency (EIT) within the atomic vapor cell, the EIT creating a transparent medium within the atomic vapor cell at the third wavelength, improving spectral brightness and / or photon linewidths.

This invention provides a Rydberg-atom based electromagnetic field receiver for a wireless telecommunications network, the electromagnetic field receiver comprising a plurality of coupling laser with one being in active state and the other ones being in preparation state, allowing a fast switching between an active laser and a prepared laser in order to provide a fast frequency hopping scheme.

A method and system for time transfer between a first clock and a second clock. The system for time transfer comprises an entangled photon transmitter, a first photon receiver, and a second photon receiver. In the first embodiment, the entangled photon transmitter is located separate from the first photon receiver, and the second photon receiver. In the second embodiment, the second photon receiver is located separate from the entangled photon transmitter and the first photon receiver. The entangled photon transmitter and the first photon receiver are co-located. In the third embodiment, the second photon receiver and the entangled photon transmitter are located separate from the first photon receiver.

This invention discloses a method and system for implementing a completely reference-frame-independent quantum key distribution protocol, belonging to the field of quantum information technology. Alice and Bob, the communicating parties, randomly select mutually unbiased basis vectors to prepare quantum states and send them to a third party, Charlie. Charlie performs Bell state projection measurements and announces the success. Both parties publish the basis vector information, divide the dataset, and calculate the gain and bit error rate. A 3×3 correlation tensor matrix is ​​constructed and singular value decomposition is performed to obtain three reference-frame-independent singular values. The secure key rate is calculated based on the bit error rate. Finally, key negotiation and security enhancement are performed to extract the secure key. This invention does not require basis vector alignment, completely eliminating the dependence on reference frame calibration. It can still stably generate keys even with basis vector drift, and the amount of information required by eavesdroppers is lower, significantly improving the practicality and security of the quantum key distribution system.