WO-2026091926-A1 - QUANTUM RECEIVING APPARATUS AND METHOD, AND LASER TERMINAL

WO2026091926A1WO 2026091926 A1WO2026091926 A1WO 2026091926A1WO-2026091926-A1

Abstract

The present application relates to the technical field of quantum communications, and in particular, to a quantum receiving apparatus and method, and a laser terminal, which are used for reducing deployment cost of a telescope, and reducing response speed and time jitter of a detection module while improving a code rate of quantum key distribution. The quantum receiving apparatus comprises: a receiving array composed of multiple telescopes, used to receive quantum light emitted by a quantum transmitting apparatus by means of a quantum channel; a detection array composed of multiple detection modules, the multiple detection modules being corresponding one-to-one with the multiple telescopes, each detection module being used to detect a light beam output by a corresponding telescope; and a detection selection module, separately connected to the multiple detection modules, and used to select a target detection module from the multiple detection modules on the basis of a detection result of the multiple detection modules, and determine an output result on the basis of the detection result of the target detection module.

Inventors

SUN, JIANFENG
ZHENG, LEI
XU, XIAOFAN
MAO, Yan

Assignees

上海卫星互联网研究院有限公司

Dates

Publication Date: 20260507
Application Date: 20250912
Priority Date: 20241028

Claims (13)

A quantum receiving device, characterized in that it comprises: A receiving array consisting of multiple telescopes is used to receive quantum light; A detection array consisting of multiple detection modules, each of which corresponds one-to-one with a multiple telescope, with each detection module used to detect the beam output by the corresponding telescope; The detection selection module is connected to the plurality of detection modules respectively, and is used to select a target detection module from the plurality of detection modules according to the detection results of the plurality of detection modules, and determine the output result according to the detection results of the target detection module.
The apparatus according to claim 1 is characterized in that it further includes a plurality of polarization-maintaining elements located between the plurality of telescopes and the plurality of detection modules, wherein the plurality of polarization-maintaining elements correspond one-to-one with the plurality of telescopes; Each polarization-maintaining element is used to couple the beam output from the corresponding telescope to the corresponding detection module.
The device according to claim 2 is characterized in that the polarization maintaining element is a free space optical polarization maintaining mirror group or a polarization maintaining fiber link.
The apparatus according to claim 1 is characterized in that each detection module includes a polarization-maintaining beam splitter and multiple single-photon detectors; The polarization-maintaining beam splitter is used to split the received beam into multiple beams with different polarization states. Each single-photon detector is used to detect the power of its corresponding beam.
The apparatus according to claim 4, wherein the detection selection module is specifically used for: Select the target detection module containing the single-photon detector with the highest detection power from among the multiple detection modules; Select one beam from the multiple beams detected by the multiple single-photon detectors of the target detection module, and use the polarization state of the selected beam as the output result.
The apparatus according to any one of claims 1 to 5 is characterized in that it further comprises a control module connected to the detection selection module and a laser communication module connected to the control module; The control module is used to acquire the output result of the detection selection module and control the laser communication module to send the output result.
The apparatus according to claim 6, wherein the laser communication module comprises an optical communication component, an optical fiber amplifier, and an optical antenna; The optical communication component is used to convert the output result into an optical signal; The fiber amplifier is used to enhance the optical signal; The optical antenna is used to transmit enhanced optical signals.
The apparatus according to any one of claims 1 to 5 is characterized in that the aperture of each telescope is on the order of tens of millimeters or hundreds of millimeters.
The apparatus according to any one of claims 1 to 5 is characterized in that the receiving array composed of the plurality of telescopes includes a one-dimensional linear array, a two-dimensional planar array, or a three-dimensional array.
A quantum receiving method, characterized in that it includes: The quantum receiving device receives quantum light emitted by the quantum transmitting device through a receiving array composed of multiple telescopes; The quantum receiving device uses multiple detection modules to detect the light beams received by the corresponding telescopes; wherein, each of the multiple detection modules corresponds one-to-one with the multiple telescopes. The quantum receiving device selects a target detection module from the multiple detection modules based on the detection results of the target detection module, and determines the output result based on the detection results of the target detection module.
According to the method of claim 10, the step of detecting the light beam received by the corresponding telescope through multiple detection modules includes: Each detection module splits the beam received by the corresponding telescope into multiple beams with different polarization states, and uses multiple single-photon detectors to detect the power of their respective beams.
According to the method of claim 10, the quantum receiving device selects a target detection module from the plurality of detection modules based on the detection results of the target detection module, and determines the output result based on the detection results of the target detection module, including: The quantum receiving device selects the target detection module containing the single-photon detector with the highest detection power from the plurality of detection modules; Select one beam from the multiple beams detected by the multiple single-photon detectors of the target detection module, and use the polarization state of the selected beam as the output result.
A laser terminal, characterized in that it includes the quantum receiving device as described in any one of claims 1 to 9.

Description

A quantum receiving device, method and laser terminal Cross-reference of related applications This application claims priority to Chinese Patent Application No. 202411519408.X, filed on October 28, 2024, entitled "A Quantum Receiving Device, Method and Laser Terminal", the entire contents of which are incorporated herein by reference. Technical Field This application relates to the field of quantum communication technology, and in particular to a quantum receiving device, method and laser terminal. Background Technology Quantum key distribution (QKD) is a key technology in quantum communication. Based on the physical laws of quantum mechanics, it securely distributes encryption keys between two communicating parties. Discrete quantum key distribution typically uses the quantum states (such as polarization states) of a single photon to modulate bit information (i.e., binary numbers). However, single-photon transmission of bit information faces the problem of low key generation rate (i.e., low key distribution rate), especially for free-space channels. Single-photon transmission is affected by the atmospheric channel environment, resulting in low received power at the receiver, which is even more detrimental to key generation. Currently, the code generation rate can be directly improved by increasing the receiver gain and the photon emission repetition frequency of the quantum light source at the transmitter. On the one hand, the receiver gain can be increased by increasing the aperture of the telescope at the receiver. However, increasing the aperture of the telescope increases its size and weight, usually requiring customization, and the installation process and maintenance are more complex, resulting in high deployment costs. On the other hand, increasing the photon emission repetition frequency of the quantum light source will increase the requirements for the response speed and timing jitter of the detector at the receiver, and the detection difficulty will increase accordingly. Generally, as the photon emission repetition frequency increases, detectors with higher response speeds and lower timing jitter are required. Summary of the Invention This application provides a quantum receiving device, method, and laser terminal, which can improve the quantum key distribution coding rate while reducing the deployment cost of the telescope and reducing the requirements for the response speed and time jitter of the detection module. In a first aspect, embodiments of this application provide a quantum receiving device, comprising: A receiving array consisting of multiple telescopes is used to receive quantum light; A detection array consisting of multiple detection modules, each of which corresponds one-to-one with a multiple telescope, with each detection module used to detect the beam output by the corresponding telescope; The detection selection module is connected to the plurality of detection modules respectively, and is used to select a target detection module from the plurality of detection modules according to the detection results of the plurality of detection modules, and determine the output result according to the detection results of the target detection module. In this embodiment, receiving quantum light from different angles or paths using a receiving array composed of multiple telescopes increases the receiving gain, thereby improving the quantum key generation rate without increasing the aperture of a single telescope. This reduces the deployment cost of a single telescope, increases deployment flexibility, and facilitates large-scale production. Simultaneously, using multiple detection modules to detect quantum light and selecting the detection result of a target detection module from the results of multiple modules enables time-division detection of quantum light. This allows the high-repetition-frequency quantum light to be evenly distributed across each of the multiple detection modules, reducing the time jitter requirement for each module and lowering the detection difficulty. This facilitates increasing the photon emission repetition frequency of the quantum light source, thereby improving the quantum key generation rate. In one optional implementation, it further includes a plurality of polarization-maintaining elements located between the plurality of telescopes and the plurality of detection modules, wherein the plurality of polarization-maintaining elements correspond one-to-one with the plurality of telescopes; Each polarization-maintaining element is used to couple the beam output from the corresponding telescope to the corresponding detection module. In one alternative implementation, the polarization-maintaining element includes a free-space polarization-maintaining mirror assembly or a polarization-maintaining fiber optic link. In one alternative implementation, each detection module includes a polarization-maintaining beam splitter and multiple single-photon detectors; The polariza