Quantum communication and precision measurement fusion system and method

Abstract

The invention provides a quantum communication and precision measurement fusion system and method, and relates to the technical field of quantum communication, the quantum communication and precision measurement fusion system comprises a sending end device and a receiving end device, the sending end device comprises a density sensing control unit, a first QKD device, a DAS device and a combiner, the receiving end equipment comprises a second QKD device and a wave separator; the combiner in the transmitting end equipment is connected with the wave separator in the receiving end equipment through an optical fiber link, and the wave separator is also connected with the second QKD device; the density sensing control unit is respectively in communication connection with the first QKD device and the DAS device, and a negotiation signal interface, a synchronization signal interface and a quantum signal interface of the first QKD device are connected with the combiner and are respectively used for receiving and transmitting negotiation signals and sending synchronization signals and quantum signals; a sensing interface of the DAS device is connected with the combiner and is used for generating transmit-receive sensing signals. Transmission is carried out through the same optical fiber link, and the optical fiber resource utilization rate is improved.

Description

Technical Field

[0001] The present invention relates to the field of quantum communication technology, and in particular to a system and method for integrating quantum communication and precision measurement. Background Art

[0002] In existing technologies, quantum key distribution (QKD) and fiber-optic distributed acoustic sensing (DAS) are usually deployed using independent optical fiber links, resulting in waste of optical cable resources and high system costs. Summary of the Invention

[0003] The purpose of the present invention is to address the deficiencies in the above-mentioned prior art and provide a quantum communication and precision measurement fusion system and method, so as to achieve the coupling of four signals through the quantum communication and precision measurement fusion system and transmit them through the same optical fiber link, thereby improving the utilization rate of optical fiber resources, reducing costs, and avoiding the waste of optical cable resources.

[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows: In a first aspect, an embodiment of the present application provides a quantum communication and precision measurement fusion system, wherein the quantum communication and precision measurement fusion system includes: a transmitting device and a receiving device, wherein the transmitting device includes: a density control unit, a first quantum key distribution QKD device, a fiber distributed acoustic sensing DAS device, and a combiner, and the receiving device includes: a second QKD device and a demultiplexer; the demultiplexer in the transmitting device is connected to the demultiplexer in the receiving device via an optical fiber link, and the demultiplexer is also connected to the second QKD device; The density sensing control unit is communicatively connected to the first QKD device and the DAS device respectively; the negotiation signal interface, synchronization signal interface and quantum signal interface of the first QKD device are connected to the combiner, and are respectively used for sending and receiving negotiation signals, sending synchronization signals and quantum signals; the sensing interface of the DAS device is connected to the combiner for generating and receiving sensing signals.

[0005] In an optional embodiment, the first QKD device includes: a first QKD control processing unit, a first quantum signal generating unit, a first synchronization signal generating unit, a first negotiation signal transceiver unit, a random number generator and a signal power adaptation unit. The first QKD control processing unit is connected to the density control unit for receiving a control signal. The first QKD control processing unit is connected to the first quantum signal generating unit through the random number generator, so that the first quantum signal generating unit generates the quantum signal according to the random number and the control signal. The first quantum signal generating unit is connected to the signal power adaptation unit, so that the signal power adaptation unit attenuates the quantum signal. The first QKD control processing unit is also connected to the first synchronization signal generating unit and the first negotiation signal transceiver unit respectively, so as to control the first synchronization signal generating unit to generate the synchronization signal according to the control signal, and to control the first negotiation signal transceiver unit to transmit and receive the negotiation signal.

[0006] In an optional embodiment, the DAS device includes: a DAS control processing unit, a data processing unit, a balanced detection unit, a low-noise optical amplifier, a circulator, an acousto-optic modulator, an optical coupler, a narrow-linewidth laser, and an atomic clock reference source, wherein the atomic clock reference source is connected to the input end of the narrow-linewidth laser, the output end of the narrow-linewidth laser is connected to the input end of the optical coupler, the first output end of the optical coupler is used to output a reference optical signal, the second output end of the optical coupler is connected to the input end of the acousto-optic modulator, the output end of the acousto-optic modulator is connected to the first end of the circulator, and the second end of the circulator serves as a sensing interface of the DAS device, so as to enable the acousto-optic modulator to generate and output the sensing signal; The input end of the low-noise optical amplifier is connected to the third end of the circulator, the output end of the low-noise optical amplifier is connected to the input end of the balanced detection unit, the output end of the balanced detection unit is connected to the input end of the data processing unit, and the output end of the data processing unit is connected to the DAS control processing unit.

[0007] In a second aspect, an embodiment of the present application further provides a quantum communication and precision measurement method, which is applied to the density sensing control unit of any transmitting end device described in the first aspect above, and the method includes: Sending a quantum key generation control signal to a first QKD device in the transmitting end device of the quantum communication and precision measurement fusion system according to a preset first wavelength band, so that the first QKD device uses frequency division multiplexing technology to transmit negotiation signals, synchronization signals, and quantum signals according to the first wavelength band; According to the preset second band, a precision measurement control signal is sent to the DAS device in the transmitting end device, so that the DAS device transmits the sensing signal according to the second band.

[0008] In an optional embodiment, the method further comprises: Monitoring the central wavelength deviation of the sensing signal to obtain a monitoring result; Based on the monitoring results, the synchronization signal and the optical fiber compensation control signal corresponding to the quantum signal are generated and sent to the processing device corresponding to each signal, so that the processing device corresponding to each signal performs optical compensation on the corresponding signal based on the optical fiber compensation control signal to generate a corresponding compensated signal.

[0009] In an optional embodiment, the method further comprises: Acquiring a monitoring sensor signal collected by the DAS device for the optical fiber link; Acquire optical power monitoring data of the optical fiber link according to the monitoring sensor signal, and establish a link loss model; Predicting the power loss data of the optical fiber link according to the link loss model, the optical power monitoring data and the environmental parameters; generating a first adjustment signal for the first QKD device according to the power loss data, and sending the signal to the first QKD device, so that the first QKD device adjusts a signal power adaptation unit in the first QKD device based on the first adjustment signal; A second adjustment signal for the DAS device is generated according to the power loss data and sent to the DAS device, so that the DAS device adjusts the gain of the low-noise optical amplifier in the DAS device based on the second adjustment signal.

[0010] In an optional embodiment, the method further comprises: Obtaining a quantum key rate of the first QKD device according to a transmission parameter corresponding to the quantum signal; obtaining a sensing accuracy of the DAS device according to the sensing signal; Obtaining a first target power of the first QKD device and a second target power of the DAS device according to the quantum key rate and the sensing accuracy; performing global optimization on the first target power and the second target power; sending a first power feedback control signal to the first QKD device according to the optimized first target power, and performing power adjustment on a signal power adaptation unit in the first QKD device; A second power feedback control signal is sent to the DAS device according to the optimized second target power to adjust the power of a low-noise optical amplifier in the DAS device.

[0011] In an optional embodiment, the method further comprises: Acquiring a monitoring sensor signal collected by the DAS device for the optical fiber link; performing vibration detection on the optical fiber link according to the monitoring sensor signal; If a vibration event is detected in the optical fiber link, a key request signal is sent to the first QKD device, so that the first QKD device updates the random number key to generate a temporary session key, and uses the temporary session key to encrypt the event data block corresponding to the vibration event in the monitoring sensor signal.

[0012] In an optional embodiment, the method further comprises: Acquiring a monitoring sensor signal collected by the DAS device for the optical fiber link; acquiring phase noise data of the DAS device according to the monitoring sensor signal; The phase noise data is sent to the first QKD device as a quantum random number entropy source, so that the first QKD device optimizes random number parameters based on the quantum random number entropy source.

[0013] In an optional embodiment, the method further comprises: Acquiring a monitoring sensor signal collected by the DAS device for the optical fiber link; According to the optical fiber link phase of the monitoring sensing signal, a phase calibration signal is generated and sent to the quantum signal generation unit and the negotiation signal transceiver unit in the first QKD device, so that the quantum signal generation unit and the negotiation signal transceiver unit perform phase offset calibration based on the phase calibration signal and with the optical fiber link phase as a reference.

[0014] The beneficial effects of this application are: The embodiment of the present application provides a quantum communication and precision measurement fusion system and method, which includes: a transmitting end device and a receiving end device, wherein the transmitting end device includes: a density control unit, a first quantum key distribution QKD device, an optical fiber distributed acoustic sensor DAS device and a combiner, and the receiving end device includes: a second QKD device and a splitter; the splitter in the transmitting end device is connected to the splitter in the receiving end device via an optical fiber link, and the splitter is also connected to the second QKD device; the density control unit is respectively connected to the first QKD device and the DAS device, and the negotiation signal interface, synchronization signal interface and quantum signal interface of the first QKD device are connected to the combiner, respectively for sending and receiving negotiation signals, sending synchronization signals and quantum signals; the sensing interface of the DAS device is connected to the combiner for generating and receiving transceiver sensing signals. The coupling of four signals is achieved through the quantum communication and precision measurement fusion system, and they are transmitted through the same optical fiber link, thereby improving the utilization rate of optical fiber resources, reducing costs, and avoiding the waste of optical cable resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 A schematic diagram of a quantum communication and precision measurement fusion system provided in an embodiment of the present application; Figure 2 One of the flow charts of a quantum communication and precision measurement method provided in an embodiment of the present application; Figure 3 The second flowchart of a quantum communication and precision measurement method provided in an embodiment of the present application; Figure 4 The third flowchart of a quantum communication and precision measurement method provided in an embodiment of the present application; Figure 5 This is a fourth flow chart of a quantum communication and precision measurement method provided in an embodiment of the present application; Figure 6 Schematic diagram of a fifth flow chart of a quantum communication and precision measurement method provided in an embodiment of the present application; Figure 7 Flowchart 6 of a quantum communication and precision measurement method provided in an embodiment of the present application; Figure 8 This is the seventh flow chart of a quantum communication and precision measurement method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0018] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0019] In the description of this application, it should be noted that if the terms "upper", "lower", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the application is usually placed when in use. It is only for the convenience of describing this application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on this application.

[0020] In addition, the terms "first," "second," and the like in the description and claims of the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to these processes, methods, products, or apparatus.

[0021] It should be noted that, in the absence of conflict, the features in the embodiments of this application can be combined with each other.

[0022] Quantum Key Distribution (QKD), as the core technology of quantum secure communication, can provide an information-theoretically secure key distribution mechanism for both communicating parties, but its transmission distance and key rate are limited by the loss of the optical fiber link. In the field of precision measurement, fiber-optic distributed acoustic sensing (DAS) achieves real-time monitoring of environmental parameters by detecting phase changes in the optical fiber, but the existing system has insufficient anti-interference capabilities and lacks deep integration with secure communications. In addition, in the prior art, QKD and DAS are usually deployed using independent optical fiber links, resulting in waste of optical cable resources, high system costs, and the inability to achieve secure encrypted transmission of sensor data. Therefore, an embodiment of the present application provides a quantum communication and precision measurement fusion system that uses one optical fiber link for multi-channel signal transmission. Figure 1 A schematic diagram of a quantum communication and precision measurement fusion system provided in an embodiment of the present application is shown in FIG. Figure 1 As shown, the quantum communication and precision measurement fusion system includes: a transmitting device and a receiving device, wherein the transmitting device includes: a density control unit, a first quantum key distribution QKD device, a fiber distributed acoustic sensor DAS device and a combiner, and the receiving device includes: a second QKD device and a splitter; the combiner in the transmitting device is connected to the splitter in the receiving device through an optical fiber link, and the splitter is also connected to the second QKD device.

[0023] The density sensing control unit is communicatively connected to the first QKD device and the DAS device respectively. The negotiation signal interface, synchronization signal interface and quantum signal interface of the first QKD device are connected to the combiner, which are used to send and receive negotiation signals, send synchronization signals and quantum signals respectively; the sensing interface of the DAS device is connected to the combiner for generating and receiving sensing signals.

[0024] Specifically, the transmitting device is used to generate and transmit quantum signals, synchronization signals, negotiation signals, and sensing signals, and the receiving device is used to receive and process quantum signals, synchronization signals, and negotiation signals. The sensing control unit in the transmitting device is used to send a control signal to the first QKD device, so that the first QKD device generates quantum signals, negotiation signals, and synchronization signals based on the control signal, and sends the negotiation signal to the combiner via the negotiation signal interface, sends the quantum signal to the combiner via the quantum signal interface, and sends the synchronization signal to the combiner via the synchronization signal interface.

[0025] The density sensing control unit in the transmitting end device is further used to send a control signal to the DAS device, so that the DAS device generates a sensing signal based on the control signal and sends the sensing signal to the combiner through the sensing interface.

[0026] The combiner is used to couple the negotiation signal, quantum signal, synchronization signal, and sensing signal, and inject them into the same optical fiber link for transmission to the wavelength splitter of the receiving device. The wavelength splitter is used to separate the received signal to obtain the separated negotiation signal, quantum signal, and synchronization signal. The separated negotiation signal, quantum signal, and synchronization signal are then processed using a second QKD device. Specifically, the second QKD device includes: a second QKD control processing unit, a second negotiation signal transceiver unit, a second quantum signal generation unit, and a second synchronization signal generation unit. The second QKD control processing unit controls the second negotiation signal transceiver unit to process the separated negotiation signal, controls the second quantum signal generation unit to process the separated quantum signal, and controls the second synchronization signal generation unit to process the separated synchronization signal. The second quantum signal generation unit achieves quantum state demodulation through precise random basis vector measurement and single-photon detection, and completes key negotiation and output.

[0027] Optionally, the first QKD device includes: a first QKD control processing unit, a first quantum signal generating unit, a first synchronization signal generating unit, a first negotiation signal transceiver unit, a random number generator and a signal power adaptation unit. The first QKD control processing unit is connected to the density control unit for receiving a control signal. The first QKD control processing unit is connected to the first quantum signal generating unit through a random number generator, so that the first quantum signal generating unit generates a quantum signal according to the random number and the control signal. The first quantum signal generating unit is connected to the signal power adaptation unit, so that the signal power adaptation unit attenuates the quantum signal. The first QKD control processing unit is also connected to the first synchronization signal generating unit and the first negotiation signal transceiver unit respectively, so as to control the first synchronization signal generating unit to generate a synchronization signal according to the control signal, and to control the first negotiation signal transceiver unit to transmit and receive a negotiation signal.

[0028] Specifically, a random number generator provides the required random numbers to the first quantum signal generation unit. The first quantum signal uses a decoy state protocol to generate a quantum signal. Random numbers are used to control decoy state modulation and quantum state encoding. Finally, the signal power adaptation unit attenuates the quantum signal to a single photon quantum. This quantum signal is generated and sent to a combiner. The synchronization signal is generated by the first QKD control and processing unit as a periodic pulse signal, used to mark the continuity of the quantum signal. The generated synchronization signal is sent to the combiner and transmitted along with the quantum signal. The negotiation signal is generated by the first negotiation signal transceiver unit and used for key screening between the sending and receiving devices. The negotiation signal is also transmitted through the combiner / demultiplexer.

[0029] Optionally, the DAS device includes: a DAS control processing unit, a data processing unit, a balanced detection unit, a low-noise optical amplifier, a circulator, an acousto-optic modulator, an optical coupler, a narrow-linewidth laser and an atomic clock reference source, wherein the atomic clock reference source is connected to the input end of the narrow-linewidth laser, the output end of the narrow-linewidth laser is connected to the input end of the optical coupler, the first output end of the optical coupler is used to output a reference optical signal, the second output end of the optical coupler is connected to the input end of the acousto-optic modulator, the output end of the acousto-optic modulator is connected to the first end of the circulator, and the second end of the circulator serves as a sensing interface of the DAS device, so as to enable the acousto-optic modulator to generate and output a sensing signal.

[0030] The input end of the low-noise optical amplifier is connected to the third end of the circulator, the output end of the low-noise optical amplifier is connected to the input end of the balanced detection unit, the output end of the balanced detection unit is connected to the input end of the data processing unit, and the output end of the data processing unit is connected to the DAS control processing unit.

[0031] Specifically, the narrow-linewidth laser is synchronized by an atomic clock, and quantum precision measurement technology provides it with an ultra-stable operating frequency. The laser signal output by the narrow-linewidth laser is split into two paths through an optical coupler with a specific splitting ratio. The high-power path is used as the detection light signal and sent to an acousto-optic modulator, while the low-power path is used as the reference light signal and sent to a balanced detection unit. A fixed frequency offset is introduced by the acousto-optic modulator to generate a sensing light signal with a high extinction ratio. This signal is then input into a combiner through a circulator and then into the optical fiber link.

[0032] As incident light propagates forward in an optical fiber link, it continuously generates and returns corresponding Rayleigh scattered light (RBS). When external vibrations act on a specific location in the optical fiber link, the refractive index, length, and core diameter of the fiber at that location undergo subtle changes, causing phase shifts in both the transmitted light and the RBS light. Using a pre-set phase demodulation algorithm, the RBS phase shift can be demodulated, thereby restoring the externally disturbed waveform. Specifically, a circulator collects the RBS signal and transmits it to a low-noise optical amplifier. The low-noise optical amplifier amplifies the RBS signal and feeds it together with a reference optical signal output by an optical coupler into a balanced detection unit. The balanced detection unit then performs balanced detection and subtracts the detected electrical signals, removing DC components and common-mode noise while retaining the effective AC component. The AC component is then output to a data processing unit, which processes the AC component to generate a digital sensor signal, which is then returned to the DAS control processing unit.

[0033] In summary, the embodiment of the present application provides a quantum communication and precision measurement fusion system, which includes: a transmitting end device and a receiving end device, wherein the transmitting end device includes: a density control unit, a first quantum key distribution QKD device, an optical fiber distributed acoustic sensor DAS device and a combiner, and the receiving end device includes: a second QKD device and a splitter; the splitter in the transmitting end device is connected to the splitter in the receiving end device through an optical fiber link, and the splitter is also connected to the second QKD device; the density control unit is respectively connected to the first QKD device and the DAS device for communication, and the negotiation signal interface, synchronization signal interface and quantum signal interface of the first QKD device are connected to the combiner, which are respectively used to send and receive negotiation signals, send synchronization signals and quantum signals; the sensing interface of the DAS device is connected to the combiner for generating and receiving transceiver sensing signals. The coupling of four signals is achieved through the quantum communication and precision measurement fusion system, and they are transmitted through the same optical fiber link, which improves the utilization rate of optical fiber resources, reduces costs, and avoids waste of optical cable resources.

[0034] In order to avoid using the same optical fiber link to transmit four signals, which leads to an increase in the quantum communication bit error rate and a significant increase in the sensing phase noise, an embodiment of the present application also provides a quantum communication and precision measurement method, which is applied to the density control unit of the above-mentioned transmitting device. The quantum communication and precision measurement method provided by this application is illustrated by multiple examples in conjunction with the accompanying drawings. Figure 2 This is one of the flow charts of a quantum communication and precision measurement method provided in an embodiment of the present application, such as Figure 2 As shown, the method includes: S101. According to a preset first band, a quantum key generation control signal is sent to a first QKD device in a transmitting device in a quantum communication and precision measurement fusion system, so that the first QKD device adopts frequency division multiplexing technology according to the first band to transmit negotiation signals, synchronization signals and quantum signals.

[0035] S102 : Sending a precision measurement control signal to a DAS device in a transmitting end device according to a preset second band, so that the DAS device transmits a sensing signal according to the second band.

[0036] In this embodiment, the density control unit sends a quantum key generation control signal to the first QKD device, so that the first QKD device generates a negotiation signal, a synchronization signal and a quantum signal. At the same time, the density control unit also sends a precision measurement control signal to the DAS device, so that the DAS device generates a sensing signal.

[0037] The density control unit also pre-plans different dedicated bands for the first QKD device and the DAS device, namely the first band and the second band, so that after the first QKD device generates a negotiation signal, a synchronization signal and a quantum signal, the negotiation signal, the synchronization signal and the quantum signal are transmitted according to the first band; and after the DAS device generates a sensing signal, the sensing signal is transmitted according to the second band, thereby realizing cross-band isolation.

[0038] In addition, the first QKD device and the DAS device consider the idle time slots of the negotiation signal and the synchronization signal to transmit the DAS signal, so as to reduce the fluctuation of the overall optical signal.

[0039] In summary, an embodiment of the present application provides a quantum communication and precision measurement method, which includes: sending a quantum key generation control signal to a first QKD device in a transmitting device in a quantum communication and precision measurement fusion system according to a preset first band, so that the first QKD device uses frequency division multiplexing technology to transmit negotiation signals, synchronization signals, and quantum signals according to the first band; and sending a precision measurement control signal to a DAS device in the transmitting device according to a preset second band, so that the DAS device transmits sensing signals according to the second band. Through precise control of the preset band and cross-module collaboration, high-level isolation between cross-band and same-band time slots is achieved, meeting the coexistence requirements of single-photon quantum signals and high-power sensing signals, avoiding the increase in quantum communication bit error rate and sensing phase noise.

[0040] The present application also provides another possible implementation of quantum communication and precision measurement methods. Figure 3 The second flow chart of a quantum communication and precision measurement method provided in the embodiment of the present application is as follows: Figure 3 As shown, the method further includes: S201. Monitor the central wavelength deviation of the sensing signal to obtain a monitoring result.

[0041] S202. Generate a fiber compensation control signal corresponding to the synchronization signal and the quantum signal based on the monitoring results, and send it to the processing device corresponding to each signal, so that the processing device corresponding to each signal performs optical compensation on the corresponding signal based on the fiber compensation control signal to generate a corresponding compensated signal.

[0042] In this embodiment, a high-precision tunable optical filter is integrated at the monitoring port of the wavelength combiner / demultiplexer to perform spectral sampling on the sensor signal. The real-time spectrum is then analyzed using a fast Fourier transform (FFT) to extract the deviation between the center wavelength of the sensor signal and a preset value, thereby obtaining the monitoring result.

[0043] Based on the monitoring results and a pre-set optical compensation execution mechanism, a synchronization signal and a fiber compensation control signal corresponding to the quantum signal are generated and sent to the processing device corresponding to each signal. The processing device then performs optical compensation on the corresponding signal based on the fiber compensation control signal, generating the corresponding compensated signal. This achieves closed-loop control, resolves wavelength shift issues caused by factors such as fiber temperature drift and stress deformation, reduces transmission losses for each signal, and maintains spectral stability for quantum communication and precision sensing measurement signals over long distances.

[0044] The present application also provides another possible implementation of quantum communication and precision measurement methods. Figure 4 The third flow chart of a quantum communication and precision measurement method provided in the embodiment of the present application is as follows: Figure 4 As shown, the method further includes: S301: Acquire monitoring sensor signals collected by a DAS device for an optical fiber link.

[0045] S302: Obtain optical power monitoring data of the optical fiber link according to the monitoring sensor signal, and establish a link loss model.

[0046] S303: Predict the power loss data of the optical fiber link according to the link loss module, the optical power monitoring data and the environmental parameters.

[0047] S304: Generate a first adjustment signal for the first QKD device according to the power loss data, and send the signal to the first QKD device, so that the first QKD device adjusts the signal power adaptation unit in the first QKD device based on the first adjustment signal.

[0048] S305 : Generate a second adjustment signal for the DAS device according to the power loss data, and send the signal to the DAS device, so that the DAS device adjusts the gain of the low-noise optical amplifier in the DAS device based on the second adjustment signal.

[0049] In this embodiment, when a multi-channel signal optical fiber link is transmitted, a monitoring sensing signal, namely a backscattered signal, is generated. Specifically, the backscattered Rayleigh signal is collected by the circulator in the DAS device, and then processed by a low-noise optical amplifier, a balanced detection unit, and a data processing unit to obtain optical power monitoring data and establish a link loss module.

[0050] A pre-established link loss model is used to predict optical power monitoring data and environmental parameters (temperature, vibration) to obtain loss power data. The link loss model can adopt an LSTM neural network prediction architecture.

[0051] Based on the loss power data, a first adjustment signal is generated for the first QKD device and sent to the first QKD device, so that the first QKD device adjusts the signal power adaptation unit in the first QKD device based on the first adjustment signal, that is, adjusts the attenuation of the quantum signal by the signal power adaptation unit.

[0052] Based on the power loss data, a second adjustment signal is generated for the DAS device and sent to the DAS device, so that the DAS device adjusts the gain of the low-noise optical amplifier in the DAS device based on the second adjustment signal, that is, adjusts the gain strength of the noisy optical amplifier for the monitoring sensor signal.

[0053] By monitoring and predicting the optical power monitoring data, dynamic power adaptation between the first QKD device and the DAS device was achieved, ensuring that the quantum bit error rate remained stable at a low level while improving the DAS signal-to-noise ratio.

[0054] The present application also provides another possible implementation of quantum communication and precision measurement methods. Figure 5 This is a fourth flow chart of a quantum communication and precision measurement method provided in an embodiment of the present application, as shown in FIG. Figure 5 As shown, the method further includes: S401. Obtain a quantum key rate of a first QKD device according to a transmission parameter corresponding to a quantum signal.

[0055] S402: Obtain the sensing accuracy of the DAS device according to the sensing signal.

[0056] S403: Obtain a first target power of the first QKD device and a second target power of the DAS device according to the quantum key rate and the sensing accuracy.

[0057] S404: Globally optimize the first target power and the second target power.

[0058] S405: Send a first power feedback control signal to the first QKD device according to the optimized first target power, and perform power adjustment on the signal power adaptation unit in the first QKD device.

[0059] S406: Send a second power feedback control signal to the DAS device according to the optimized second target power, and adjust the power of the low-noise optical amplifier in the DAS device.

[0060] In this embodiment, the transmission parameters corresponding to the quantum signal may include: average photon number, signal state count rate, decoy state count rate, vacuum state count rate, signal state bit error rate, decoy state bit error rate, single photon bit error rate, etc., and the key rate calculation formula is used to calculate the quantum key rate of the first QKD device. The accuracy parameter is extracted from the sensor signal to obtain the sensing accuracy of the DAS device.

[0061] Using a multi-objective optimization function, the system balances quantum key rate and sensing accuracy through an optimization algorithm to obtain the first target power of the first QKD device and the second target power of the DAS device. The system then performs global optimization of the first and second target powers. Based on the optimized first target power, a first power feedback control signal is sent to the first QKD device, adjusting the power of the signal power adapter unit in the first QKD device. Based on the optimized second target power, a second power feedback control signal is sent to the DAS device, adjusting the power of the low-noise optical amplifier in the DAS device. In scenarios with high optical fiber link loss, this system improves the quantum key rate and sensing phase demodulation accuracy, enabling variable power allocation and breaking through the performance bottleneck of traditional fixed power allocation.

[0062] The present application also provides another possible implementation of quantum communication and precision measurement methods. Figure 6 This is a fifth flow chart of a quantum communication and precision measurement method provided in an embodiment of the present application, as shown in FIG. Figure 6 As shown, the method further includes: S501: Acquire monitoring sensor signals collected by a DAS device for an optical fiber link.

[0063] S502: Perform vibration detection on the optical fiber link according to the monitoring sensor signal.

[0064] S503. If a vibration event is detected in the optical fiber link, a key request signal is sent to the first QKD device, so that the first QKD device updates the random number key to generate a temporary session key, and uses the temporary session key to encrypt the event data block corresponding to the vibration event in the monitoring sensor signal.

[0065] In this embodiment, a backward Rayleigh scattering signal, i.e., a monitoring sensing signal, is generated in the optical fiber link. The monitoring sensing signal is collected by a circulator to obtain corresponding noise, and vibration detection is performed. For example, if it is determined that a noise jump occurs in the monitoring sensing signal, it is determined that a vibration event exists in the optical fiber link, and an event data block corresponding to the vibration event is obtained.

[0066] A key request signal is sent to the first QKD device to trigger the random number generator in the first QKD device to update the random number key and generate a temporary session key. The temporary session key is used to encrypt the event data block corresponding to the vibration event in the monitoring sensor signal, realizing the "abnormal event perception-key update-data encryption" closed loop and improving the response capability to real-time security threats.

[0067] The present application also provides another possible implementation of quantum communication and precision measurement methods. Figure 7The sixth flow chart of a quantum communication and precision measurement method provided in the embodiment of the present application is as follows: Figure 7 As shown, the method further includes: S601: Acquire monitoring sensor signals collected by a DAS device for an optical fiber link.

[0068] S602: Acquire phase noise data of the DAS device according to the monitoring sensor signal.

[0069] S603: Send the phase noise data as a quantum random number entropy source to the first QKD device, so that the first QKD device optimizes the random number parameters based on the quantum random number entropy source.

[0070] In this embodiment, a backward Rayleigh scattering signal, i.e., a monitoring sensor signal, is generated in the optical fiber link. The monitoring sensor signal is collected through a circulator to obtain corresponding phase noise data, including physical entropy sources such as environmental vibration and temperature fluctuations. The phase noise data is then used as a quantum random number entropy source and sent to the random number generator in the first QKD device. The random number parameters are dynamically optimized through the entropy estimation module to improve the pass rate of key randomness detection and meet higher security level requirements.

[0071] The present application also provides another possible implementation of quantum communication and precision measurement methods. Figure 8 The seventh flow chart of a quantum communication and precision measurement method provided in the embodiment of the present application is as follows: Figure 8 As shown, the method further includes: S701: Acquire monitoring sensor signals collected by a DAS device for an optical fiber link.

[0072] S702. Generate a phase calibration signal based on the optical fiber link phase of the monitored sensing signal and send it to the quantum signal generation unit and the negotiation signal transceiver unit in the first QKD device, so that the quantum signal generation unit and the negotiation signal transceiver unit perform phase offset calibration based on the phase calibration signal and the optical fiber link phase as a reference.

[0073] In this embodiment, a backward Rayleigh scattering signal, i.e., a monitoring sensing signal, is generated in the optical fiber link. The monitoring sensing signal is collected by a circulator to obtain the optical fiber link phase of the monitoring sensing signal. Then, based on the optical fiber link phase of the monitoring sensing signal, a phase calibration signal is generated and sent to the quantum signal generation unit and the negotiation signal transceiver unit in the first QKD device, so that the quantum signal generation unit and the negotiation signal transceiver unit perform phase offset calibration based on the phase calibration signal and with the optical fiber link phase as a reference.

[0074] Through the deep collaboration of DAS distributed phase monitoring and QKD phase calibration, a closed-loop control mechanism of "fiber link phase reference-real-time offset detection-dynamic calibration execution" was constructed, breaking through the limitations of traditional electrical signal calibration affected by temperature, eliminating the phase noise caused by temperature changes, and achieving improved accuracy of quantum state demodulation.

[0075] The above are only specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A quantum communication and precision measurement fusion system, characterized in that: The quantum communication and precision measurement fusion system includes: a transmitting device and a receiving device, wherein the transmitting device includes: a density control unit, a first quantum key distribution (QKD) device, a fiber distributed acoustic sensing (DAS) device, and a combiner, and the receiving device includes: a second QKD device and a demultiplexer; the demultiplexer in the transmitting device is connected to the demultiplexer in the receiving device via an optical fiber link, and the demultiplexer is also connected to the second QKD device; The density sensing control unit is communicatively connected to the first QKD device and the DAS device respectively; the negotiation signal interface, synchronization signal interface and quantum signal interface of the first QKD device are connected to the combiner, and are respectively used for sending and receiving negotiation signals, sending synchronization signals and quantum signals; the sensing interface of the DAS device is connected to the combiner for generating and receiving sensing signals.

2. The system according to claim 1, wherein: The first QKD device includes: a first QKD control processing unit, a first quantum signal generating unit, a first synchronization signal generating unit, a first negotiation signal transceiver unit, a random number generator and a signal power adaptation unit. The first QKD control processing unit is connected to the density control unit for receiving a control signal. The first QKD control processing unit is connected to the first quantum signal generating unit through the random number generator, so that the first quantum signal generating unit generates the quantum signal according to the random number and the control signal. The first quantum signal generating unit is connected to the signal power adaptation unit so that the signal power adaptation unit attenuates the quantum signal. The first QKD control processing unit is also connected to the first synchronization signal generating unit and the first negotiation signal transceiver unit respectively, so as to control the first synchronization signal generating unit to generate the synchronization signal according to the control signal, and to control the first negotiation signal transceiver unit to transmit and receive the negotiation signal.

3. The system according to claim 1, wherein: The DAS device includes: a DAS control processing unit, a data processing unit, a balanced detection unit, a low-noise optical amplifier, a circulator, an acousto-optic modulator, an optical coupler, a narrow-linewidth laser, and an atomic clock reference source, wherein the atomic clock reference source is connected to the input end of the narrow-linewidth laser, the output end of the narrow-linewidth laser is connected to the input end of the optical coupler, the first output end of the optical coupler is used to output a reference optical signal, the second output end of the optical coupler is connected to the input end of the acousto-optic modulator, the output end of the acousto-optic modulator is connected to the first end of the circulator, and the second end of the circulator serves as a sensing interface of the DAS device, so as to enable the acousto-optic modulator to generate and output the sensing signal; The input end of the low-noise optical amplifier is connected to the third end of the circulator, the output end of the low-noise optical amplifier is connected to the input end of the balanced detection unit, the output end of the balanced detection unit is connected to the input end of the data processing unit, and the output end of the data processing unit is connected to the DAS control processing unit.

4. A quantum communication and precision measurement method, characterized in that: The density sensing control unit applied to the transmitting end device according to any one of claims 1 to 3 above, the method comprising: Sending a quantum key generation control signal to a first QKD device in the transmitting end device of the quantum communication and precision measurement fusion system according to a preset first wavelength band, so that the first QKD device uses frequency division multiplexing technology to transmit negotiation signals, synchronization signals, and quantum signals according to the first wavelength band; According to the preset second band, a precision measurement control signal is sent to the DAS device in the transmitting end device, so that the DAS device transmits the sensing signal according to the second band.

5. The method according to claim 4, characterized in that The method further comprises: monitoring the central wavelength deviation of the sensing signal to obtain a monitoring result, Based on the monitoring results, the synchronization signal and the optical fiber compensation control signal corresponding to the quantum signal are generated and sent to the processing device corresponding to each signal, so that the processing device corresponding to each signal performs optical compensation on the corresponding signal based on the optical fiber compensation control signal to generate a corresponding compensated signal.

6. The method according to claim 4, characterized in that The method further comprises: Acquiring a monitoring sensor signal collected by the DAS device for the optical fiber link; Acquire optical power monitoring data of the optical fiber link according to the monitoring sensor signal, and establish a link loss model; Predicting the power loss data of the optical fiber link according to the link loss model, the optical power monitoring data and the environmental parameters; generating a first adjustment signal for the first QKD device according to the power loss data, and sending the signal to the first QKD device, so that the first QKD device adjusts a signal power adaptation unit in the first QKD device based on the first adjustment signal; A second adjustment signal for the DAS device is generated according to the power loss data and sent to the DAS device, so that the DAS device adjusts the gain of the low-noise optical amplifier in the DAS device based on the second adjustment signal.

7. The method according to claim 4, characterized in that The method further comprises: Obtaining a quantum key rate of the first QKD device according to a transmission parameter corresponding to the quantum signal; obtaining a sensing accuracy of the DAS device according to the sensing signal; Obtaining a first target power of the first QKD device and a second target power of the DAS device according to the quantum key rate and the sensing accuracy; performing global optimization on the first target power and the second target power; sending a first power feedback control signal to the first QKD device according to the optimized first target power, and performing power adjustment on a signal power adaptation unit in the first QKD device; A second power feedback control signal is sent to the DAS device according to the optimized second target power to adjust the power of a low-noise optical amplifier in the DAS device.

8. The method according to claim 4, characterized in that The method further comprises: Acquiring a monitoring sensor signal collected by the DAS device for the optical fiber link; performing vibration detection on the optical fiber link according to the monitoring sensor signal; If a vibration event is detected in the optical fiber link, a key request signal is sent to the first QKD device, so that the first QKD device updates the random number key to generate a temporary session key, and uses the temporary session key to encrypt the event data block corresponding to the vibration event in the monitoring sensor signal.

9. The method according to claim 4, characterized in that The method further comprises: Acquiring a monitoring sensor signal collected by the DAS device for the optical fiber link; acquiring phase noise data of the DAS device according to the monitoring sensor signal; The phase noise data is sent to the first QKD device as a quantum random number entropy source, so that the first QKD device optimizes random number parameters based on the quantum random number entropy source.

10. The method according to claim 4, characterized in that The method further comprises: Acquiring a monitoring sensor signal collected by the DAS device for the optical fiber link; According to the optical fiber link phase of the monitoring sensing signal, a phase calibration signal is generated and sent to the quantum signal generation unit and the negotiation signal transceiver unit in the first QKD device, so that the quantum signal generation unit and the negotiation signal transceiver unit perform phase offset calibration based on the phase calibration signal and with the optical fiber link phase as a reference.

Images