A quantum communication and sensing system based on synchronization signal multiplexing

Abstract

The application provides a quantum communication and sensing system based on synchronization signal multiplexing, and relates to the technical field of quantum communication. The system comprises a sending end device and a receiving end device. The sending end device comprises a first secret sensing control unit, a quantum signal generation and negotiation device, a synchronization signal multiplexing device and a combiner. The receiving end device comprises a second secret sensing control unit, a quantum signal receiving and negotiation device and a splitter. The combiner is connected to the splitter through an optical fiber link. The first secret sensing control unit is connected to the quantum signal generation and negotiation device and the synchronization signal multiplexing device. The negotiation signal interface and the quantum signal interface of the quantum signal generation and negotiation device are connected to the combiner, and are used for receiving and transmitting negotiation signals and sending quantum signals. The sensing interface of the synchronization signal multiplexing device is connected to the combiner, and generates and sends synchronization signal multiplexing as sensing signals. The second secret sensing control unit is connected to the splitter through the quantum signal receiving and negotiation device, and the number of signal optical paths is reduced.

Description

Technical Field

[0001] The present invention relates to the field of quantum communication technology, and in particular to a quantum communication and sensing system based on synchronous signal multiplexing. Background Art

[0002] In existing technologies, quantum key distribution (QKD) and fiber-based distributed acoustic sensing (DAS) are typically deployed using independent fiber links, resulting in wasted optical cable resources, high system costs, and the inability to securely and encryptedly transmit sensor data. Even attempts to integrate QKD and DAS through shared fiber transmission remain limited to hardware-level link sharing. Conventional combiners and splitters lack sufficient isolation capabilities to accommodate the coexistence of single-photon quantum signals and high-power sensor signals. Signal crosstalk can lead to increased bit error rates in quantum communication and significantly increased sensor phase noise. 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 sensing system based on synchronization signal multiplexing, so as to multiplex the synchronization signal into the sensing signal, reduce the number of sensing signal optical paths, and reduce the power interference suffered by the quantum signal.

[0004] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0005] In a first aspect, an embodiment of the present application provides a quantum communication and sensing system based on synchronous signal multiplexing, the quantum communication and sensing system comprising: a transmitting device and a receiving device, wherein the transmitting device comprises: a first density sensing control unit, a quantum signal generation and negotiation device, a synchronous signal multiplexing device, and a combiner; the receiving device comprises: a second density sensing control unit, a quantum signal reception and negotiation device, and a splitter; the splitter is connected to the splitter via an optical fiber link;

[0006] The first density sensing control unit is communicatively connected to the quantum signal generation and negotiation device and the synchronization signal multiplexing device, respectively. The negotiation signal interface and the quantum signal interface of the quantum signal generation and negotiation device are connected to the combiner, respectively for receiving and sending negotiation signals and sending quantum signals; the sensing interface of the synchronization signal multiplexing device is connected to the combiner, for generating and sending synchronization signals multiplexed into sensing signals, and receiving backward Rayleigh scattered RBS optical signals of the synchronization signals as sensing signals;

[0007] The second density control unit is connected to the splitter through the quantum signal receiving and negotiation device.

[0008] In an optional embodiment, the quantum signal generation and negotiation device includes: a first quantum key generation control unit, a random number generator, a negotiation signal transceiver unit, and a quantum signal generation unit;

[0009] The first quantum key generation control unit is connected to the first secret control unit, the first quantum key generation control unit is further connected to the random number generator, and the first quantum key generation control unit is further connected to the quantum signal generation unit for generating the quantum signal;

[0010] The first quantum key generation control unit is also connected to the negotiation signal transceiver unit for transmitting and receiving the negotiation signal.

[0011] In an optional embodiment, the synchronization signal multiplexing device includes: a precision sensing control unit, a synchronization signal generating unit, a circulator, and a sensing signal receiving unit;

[0012] The precision sensing control unit is connected to the first density sensing control unit, the precision sensing control unit is connected to the synchronization signal generating unit, the synchronization signal generating unit is further connected to the first end of the circulator, and is used to generate the synchronization signal and send it through the second end of the circulator;

[0013] The synchronization signal generating unit is also connected to the sensing signal receiving unit to output a reference optical signal. The sensing signal receiving unit is also connected to the third end of the circulator, and is used to receive the RBS optical signal collected by the second end of the circulator through the third end, and generate a digital sensing signal based on the reference optical signal and the RBS optical signal. The sensing signal receiving unit is also connected to the precision sensing control unit to transmit the digital sensing signal to the precision sensing control unit.

[0014] In an optional embodiment, the synchronization signal generating unit includes: an atomic clock reference source, a continuous light laser, a first optical coupler, and an acousto-optic modulator, wherein the atomic clock reference source is connected to an input end of the continuous light laser so that the continuous light laser generates a continuous light signal based on the atomic clock reference signal;

[0015] The control end of the continuous light laser is connected to the precision sensor control unit, the output end of the continuous light laser is connected to the input end of the first optical coupler, the first output end of the first optical coupler is used to output the reference light signal, and the second output end of the first optical coupler is connected to the input end of the acousto-optic modulator, so that the first optical coupler divides the continuous light signal into a detection light signal and the reference light signal; the output end of the acousto-optic modulator is connected to the first end of the circulator, so that the acousto-optic modulator generates and outputs the synchronization signal based on the detection light signal.

[0016] In an optional embodiment, the sensing signal receiving unit includes: a low-noise optical amplifier, a second optical coupler, a balanced detector, and a data processing unit; the input end of the low-noise optical amplifier is connected to the third end of the circulator for collecting the RBS optical signal, the output end of the low-noise optical amplifier is connected to the first input end of the second optical coupler, so that the low-noise optical amplifier amplifies the RBS optical signal, and the second input end of the second optical coupler is connected to the synchronization signal generating unit for receiving the reference optical signal;

[0017] The output end of the second optical coupler is connected to the input end of the balanced detector, so that the second optical coupler divides the enhanced RBS optical signal into two RBS optical signals based on the reference optical signal. The output end of the balanced detector is connected to the input end of the data processing unit, so that the balanced detector performs balanced detection on the two RBS optical signals and outputs the detection results to the data processing unit. The output end of the data processing unit is connected to the precision sensing control unit, so that the data processing unit processes the detection results and outputs the digital sensing signal to the precision sensing control unit.

[0018] In an optional embodiment, the precision sensing control unit is configured to perform closed-loop control on the frequency of the continuous light laser according to the digital sensing signal.

[0019] In an optional embodiment, the precision sensing control unit further performs closed-loop control on the amplification gain of the low-noise optical amplifier and the acquisition rate of the data processing unit according to the digital sensing signal.

[0020] In an optional embodiment, the quantum communication and sensing system further includes: a quantum key scheduling device, which is connected to the first key sensing control unit and is configured to generate a quantum key scheduling control signal according to a security requirement instruction of an upper-layer device, and send the signal to the first key sensing control unit, so that the first key sensing control unit generates a quantum key generation control signal according to the key scheduling control signal and sends the signal to the quantum signal generation and negotiation device, so that the quantum signal generation and negotiation device generates a quantum key.

[0021] In an optional embodiment, the quantum key scheduling device includes: a quantum key scheduling control unit, a management interface unit, and a key output unit;

[0022] The quantum key scheduling control unit is connected to the management interface unit to obtain the security requirement instruction through the management interface unit, and the quantum key scheduling control unit is also connected to the first secret control unit to obtain the quantum key generated by the quantum signal generation and negotiation device through the first secret control unit;

[0023] The quantum key scheduling control unit is also connected to the key output unit to send the quantum key to the upper-layer device through the key output unit.

[0024] In an optional embodiment, the quantum signal generation unit includes: a pulse laser, a decoy state modulation unit, a quantum state modulation unit, and a signal power adaptation unit, wherein the pulse laser is connected to the input end of the decoy state modulation unit to output a pulse laser to the decoy state modulation unit, and the output end of the decoy state modulation unit is connected to the input end of the quantum state modulation unit, so that the decoy state modulation unit switches the pulse laser to obtain a decoy state coded signal;

[0025] The output end of the quantum state modulation unit is connected to the input end of the signal power adaptation unit, so that the quantum state modulation unit encodes the decoy state coded signal to obtain the quantum signal to be attenuated. The output end of the signal power adaptation unit is connected to a combiner for attenuating the quantum signal to be attenuated, obtaining and outputting the quantum signal.

[0026] The beneficial effects of this application are:

[0027] An embodiment of the present application provides a quantum communication and sensing system based on synchronous signal multiplexing, and the quantum communication and sensing system includes: a transmitting end device and a receiving end device, wherein the transmitting end device includes: a first dense sensing control unit, a quantum signal generation and negotiation device, a synchronous signal multiplexing device and a combiner, and the receiving end device includes: a second dense sensing control unit, a quantum signal receiving and negotiation device and a splitter; the combiner is connected to the splitter through an optical fiber link; the first dense sensing control unit is communicatively connected to the quantum signal generation and negotiation device and the synchronous signal multiplexing device respectively, and the negotiation signal interface and the quantum signal interface of the quantum signal generation and negotiation device are connected to the combiner, which are respectively used to receive and send negotiation signals and send quantum signals; the sensing interface of the synchronous signal multiplexing device is connected to the combiner, which is used to generate and send synchronization signals multiplexed into sensing signals, and receive the backward Rayleigh scattered RBS optical signal of the synchronization signal as a sensing signal; the second dense sensing control unit is connected to the splitter through the quantum signal receiving and negotiation device. Since the synchronization signal is multiplexed into the sensing signal, the number of sensing signal optical paths is reduced, thereby effectively reducing the power interference suffered by the quantum signal. At the same time, the periodic characteristics of the synchronization signal are utilized to improve the time resolution of the sensing signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 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.

[0029] Figure 1 A schematic diagram of a quantum communication and sensing system based on synchronous signal multiplexing provided in an embodiment of the present application;

[0030] Figure 2 A schematic diagram of another quantum communication and sensing system based on synchronous signal multiplexing provided in an embodiment of the present application;

[0031] Figure 3 A schematic diagram of another quantum communication and sensing system based on synchronous signal multiplexing provided in an embodiment of the present application;

[0032] Figure 4 A schematic diagram of another quantum communication and sensing system based on synchronous signal multiplexing provided in an embodiment of the present application. DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] It should be noted that, in the absence of conflict, the features in the embodiments of this application can be combined with each other.

[0038] Quantum Key Distribution (QKD), a core technology for quantum secure communication, provides an information-theoretically secure key distribution mechanism for communicating parties based on fundamental principles of quantum mechanics (such as the quantum no-cloning theorem and measurement collapse). Combined with "one-time pad" encryption, QKD can mitigate the computational power attacks faced by traditional cryptography, enabling unconditionally secure confidential communication. However, QKD systems are sensitive to fiber link loss, and their transmission distance and key rate are limited by the attenuation characteristics of single-photon signals.

[0039] Fiber-based distributed acoustic sensing (DAS) achieves distributed, real-time monitoring of environmental parameters such as vibration and temperature by detecting phase changes in Rayleigh Backward Scattering (RBS) optical signals. However, DAS systems lack the ability to deeply integrate with QKD. The sensing signals are susceptible to noise interference and do not achieve secure encrypted transmission. Furthermore, when the weak QKD quantum signal (-70 dBm to -80 dBm) coexists with the DAS sensing signal, optical path crosstalk and insertion loss can easily lead to increased bit error rates or decreased sensing accuracy. Therefore, an embodiment of the present application provides a quantum communication and sensing system based on synchronous signal multiplexing. By multiplexing the QKD synchronous optical signal as the sensing signal carrier, the number of co-fiber transmission optical paths is reduced, achieving a deep integration of quantum communication and precision measurement functions.

[0040] The quantum communication and sensing system based on synchronous signal multiplexing provided by the present application is illustrated below through multiple examples in conjunction with the accompanying drawings. Figure 1 A schematic diagram of a quantum communication and sensing system based on synchronous signal multiplexing provided in an embodiment of the present application is shown in FIG. Figure 1As shown, the quantum communication and sensing system includes: a transmitting device and a receiving device, wherein the transmitting device includes: a first density sensing control unit, a quantum signal generating and negotiation device, a synchronization signal multiplexing device and a combiner, and the receiving device includes: a second density sensing control unit, a quantum signal receiving and negotiation device and a splitter; the combiner is connected to the splitter via an optical fiber link.

[0041] The first density sensing control unit is communicatively connected to the quantum signal generation and negotiation device and the synchronization signal multiplexing device respectively. The negotiation signal interface and the quantum signal interface of the quantum signal generation and negotiation device are connected to the combiner, which are respectively used to send and receive negotiation signals and send quantum signals; the sensing interface of the synchronization signal multiplexing device is connected to the combiner, which is used to generate and send synchronization signals multiplexed into sensing signals, and receive the backward Rayleigh scattered RBS optical signal of the synchronization signal as a sensing signal.

[0042] The second density control unit is connected to the splitter through the quantum signal receiving and negotiation device.

[0043] In this embodiment, the transmitting device is used to generate and transmit quantum signals, synchronization signals, negotiation signals, and sensing signals. Since the synchronization signal is multiplexed into the sensing signal in this application, the transmitting device only transmits the quantum signals, synchronization signals, and negotiation signals. The receiving device is used to receive and process the quantum signals, synchronization signals, and negotiation signals.

[0044] Among them, the first key-sensing control unit is used to centrally manage quantum key generation, scheduling and sensing functions, realize timing synchronization and dynamic resource allocation between modules, the quantum signal generation and negotiation device is used to generate quantum signals and negotiation signals, and the quantum signal receiving and negotiation device is used to receive quantum signals and negotiation signals.

[0045] The first density sensing control unit in the sending end device is used to send a control signal to the quantum signal generation and negotiation device, so that the quantum signal generation and negotiation device generates a quantum signal and a negotiation signal based on the control signal, and sends the negotiation signal to the combiner through the negotiation signal interface, and sends the quantum signal to the combiner through the quantum signal interface.

[0046] The first density sensing control unit in the sending end device is also used to send a control signal to the synchronization signal multiplexing device, so that the synchronization signal multiplexing device generates a synchronization signal, i.e., a sensing signal, based on the control signal, and sends the synchronization signal to the combiner through the sensing interface. The synchronization signal multiplexing device can also receive the backward Rayleigh scattered RBS optical signal of the synchronization signal in the optical fiber link through the sensing interface.

[0047] The combiner is used to couple the negotiation signal, quantum signal and synchronization signal, and inject them into the same optical fiber link for transmission to the splitter of the receiving device.

[0048] The wave splitter is used to separate the received signal to obtain a separated negotiation signal, quantum signal, and synchronization signal. The second key sensing control unit then processes the separated negotiation signal, quantum signal, and synchronization signal in the quantum signal receiving and negotiation device. Specifically, the quantum signal receiving and negotiation device includes: a second quantum key generation control unit, a negotiation signal receiving unit, a quantum signal receiving unit, and a synchronization signal receiving unit. The second quantum key generation control unit controls the negotiation signal receiving unit to process the separated negotiation signal, controls the quantum signal receiving unit to process the separated quantum signal, and controls the synchronization signal receiving unit to process the separated synchronization signal.

[0049] It should be noted that both the combiner and the splitter use high-isolation and low-insertion-loss devices to achieve physical isolation between quantum signals and sensing signals, i.e., synchronization signals, while reducing the insertion loss to below 0.3dB to avoid quantum signal attenuation.

[0050] In summary, an embodiment of the present application provides a quantum communication and sensing system based on synchronous signal multiplexing, and the quantum communication and sensing system includes: a transmitting end device and a receiving end device, wherein the transmitting end device includes: a first dense sensing control unit, a quantum signal generation and negotiation device, a synchronous signal multiplexing device and a combiner, and the receiving end device includes: a second dense sensing control unit, a quantum signal receiving and negotiation device and a splitter; the combiner is connected to the splitter through an optical fiber link; the first dense sensing control unit is respectively connected to the quantum signal generation and negotiation device and the synchronous signal multiplexing device, and the negotiation signal interface and the quantum signal interface of the quantum signal generation and negotiation device are connected to the combiner, which are respectively used to receive and send negotiation signals and send quantum signals; the sensing interface of the synchronous signal multiplexing device is connected to the combiner, which is used to generate and send synchronization signals multiplexed into sensing signals, and receive the backward Rayleigh scattered RBS optical signal of the synchronization signal as a sensing signal; the second dense sensing control unit is connected to the splitter through the quantum signal receiving and negotiation device. Since the synchronization signal is multiplexed into the sensing signal, the number of sensing signal optical paths is reduced, thereby effectively reducing the power interference suffered by the quantum signal. At the same time, the periodic characteristics of the synchronization signal are utilized to improve the time resolution of the sensing signal.

[0051] The present application also provides another possible implementation of a quantum communication and sensing system based on synchronous signal multiplexing. Figure 2 This is a schematic diagram of another quantum communication and sensing system based on synchronous signal multiplexing provided in an embodiment of the present application. Figure 2 As shown, the quantum signal generation and negotiation device includes: a first quantum key generation control unit, a random number generator, a negotiation signal transceiver unit and a quantum signal generation unit.

[0052] The first quantum key generation control unit is connected to the first secret control unit, the first quantum key generation control unit is also connected to the random number generator, and the first quantum key generation control unit is also connected to the quantum signal generation unit for generating quantum signals.

[0053] The first quantum key generation control unit is also connected to the negotiation signal transceiver unit for sending and receiving negotiation signals.

[0054] In this embodiment, the first key sensing control unit sends a control signal to the first quantum key generation control unit, and the random number generator is used to provide a random number to the first quantum key generation control unit, so that the first quantum key generation control unit controls the quantum signal generation unit to generate a quantum signal based on the control signal and the random number, and controls the negotiation signal transceiver unit to generate and transmit and receive a negotiation signal, wherein the negotiation signal is used for key screening by the sending device and the receiving device.

[0055] Optionally, the quantum signal generation unit includes: a pulse laser, a lured state modulation unit, a quantum state modulation unit and a signal power adaptation unit, the pulse laser is connected to the input end of the lured state modulation unit, and is used to output a pulse laser to the lured state modulation unit, and the output end of the lured state modulation unit is connected to the input end of the quantum state modulation unit, so that the lured state modulation unit switches the pulse laser to obtain a lured state coded signal.

[0056] The output end of the quantum state modulation unit is connected to the input end of the signal power adaptation unit, so that the quantum state modulation unit encodes the decoy state coded signal to obtain the quantum signal to be attenuated. The output end of the signal power adaptation unit is connected to the combiner, which is used to attenuate the quantum signal to be attenuated, obtain and output the quantum signal.

[0057] For details, please refer to Figure 2 The quantum signal generation unit uses the decoy state BB84 protocol for quantum key distribution. After the pulse laser generates pulse laser, the decoy state modulation unit realizes random switching between the signal state, decoy state and vacuum state, thereby obtaining the decoy state coded signal. The quantum state modulation unit then encodes the optical pulse, i.e., the decoy state coded signal, based on the two-dimensional Hilbert space orthogonal basis to obtain the quantum signal to be attenuated. The signal power adaptation unit attenuates the quantum signal to be attenuated to the single-photon level (-70 dBm ~ -80 dBm), and adjusts the transmission power in real time through the dynamic power management algorithm to reduce the quantum bit error rate, thereby obtaining the quantum signal and sending it to the combiner through the quantum signal interface.

[0058] The present application also provides another possible implementation of a quantum communication and sensing system based on synchronous signal multiplexing. Figure 3 This is a schematic diagram of another quantum communication and sensing system based on synchronous signal multiplexing provided in an embodiment of the present application. Figure 3 The synchronization signal multiplexing device comprises a precision sensing control unit, a synchronization signal generating unit, a circulator and a sensing signal receiving unit.

[0059] The precision sensing control unit is connected to the first sensitive control unit, and the precision sensing control unit is connected to the synchronization signal generating unit, and the synchronization signal generating unit is also connected to the first end of the circulator, for generating a synchronization signal and sending it out through the second end of the circulator.

[0060] The synchronization signal generating unit is also connected to the sensing signal receiving unit to output a reference light signal, and the sensing signal receiving unit is also connected to the third end of the circulator, for receiving the RBS light signal collected by the second end of the circulator through the third end, and generating a digital sensing signal according to the reference light signal and the RBS light signal, and the sensing signal receiving unit is also connected to the precision sensing control unit to transmit the digital sensing signal to the precision sensing control unit.

[0061] In this embodiment, the first sensitive control unit sends a control signal to the precision sensing control unit, so that the precision sensing control unit controls the synchronization signal generating unit to generate a synchronization signal and sends it to the combiner through the circulator, and controls the sensing receiving unit to receive and process the RBS light signal to obtain a digital sensing signal, and returns the digital sensing signal to the precision sensing control unit.

[0062] Optionally, the synchronization signal generating unit comprises an atomic clock reference source, a continuous light laser, a first optical coupler and an acousto-optic modulator, and the atomic clock reference source is connected to the input end of the continuous light laser, so that the continuous light laser generates a continuous light signal based on the atomic clock reference signal.

[0063] The control end of the continuous light laser is connected to the precision sensing control unit, the output end of the continuous light laser is connected to the input end of the first optical coupler, the first output end of the first optical coupler is used for outputting a reference light signal, and the second output end of the first optical coupler is connected to the input end of the acousto-optic modulator, so that the first optical coupler divides the continuous light signal into a probe light signal and a reference light signal; the output end of the acousto-optic modulator is connected to the first end of the circulator, for making the acousto-optic modulator generate and output a synchronization signal based on the probe light signal.

[0064] Specifically, the continuous light laser in the synchronization signal generating unit generates a high-stability continuous light signal based on the atomic clock reference source, and then divides the continuous light signal into two paths through the first optical coupler, one path as a probe light signal and the other path as a reference light signal, then sends the probe light signal to the acousto-optic modulator and the reference light signal to the sensing signal receiving unit. Then introduce a fixed frequency offset through the acousto-optic modulator, and generate a synchronization signal with high extinction ratio based on the probe light signal, that is, a sensing signal, and finally input it to the combiner through the circulator.

[0065] Optionally, the sensing signal receiving unit includes: a low-noise optical amplifier, a second optical coupler, a balanced detector, and a data processing unit; the input end of the low-noise optical amplifier is connected to the third end of the circulator for collecting the RBS optical signal, the output end of the low-noise optical amplifier is connected to the first input end of the second optical coupler, so that the low-noise optical amplifier enhances the RBS optical signal, and the second input end of the second optical coupler is connected to the synchronization signal generating unit for receiving the reference optical signal.

[0066] The output end of the second optical coupler is connected to the input end of the balanced detector, so that the second optical coupler divides the enhanced RBS optical signal into two RBS optical signals based on the reference optical signal. The output end of the balanced detector is connected to the input end of the data processing unit, so that the balanced detector performs balanced detection on the two RBS optical signals and outputs the detection results to the data processing unit. The output end of the data processing unit is connected to the precision sensing control unit, so that the data processing unit processes the detection results and outputs a digital sensing signal to the precision sensing control unit.

[0067] Specifically, since an RBS optical signal is generated when incident light propagates in an optical fiber, when external vibration acts on the sensing optical fiber, the phase of the RBS optical signal changes. Therefore, the sensing signal receiving unit collects the RBS optical signal generated in the optical fiber link through a circulator and transmits it to a low-noise optical amplifier. After the low-noise optical amplifier amplifies the RBS optical signal, it is input into a second optical coupler together with a reference optical signal. The second optical coupler divides the amplified RBS optical signal into two RBS optical signals based on the reference optical signal, and then outputs them to a balanced detector. The balanced detector performs balanced detection on the two RBS optical signals, removes DC components and common-mode noise, and retains effective AC components to obtain detection results. The detection results are then output to a data processing unit, which processes the detection results to obtain digital sensing information and returns it to the precision sensing control unit.

[0068] Because the synchronization signal is multiplexed into the sensing signal, there's no need to add a new sensing signal, thus preventing interference with the quantum signal and increasing both the code rate and transmission distance. Furthermore, phase changes in the RBS signal directly reflect environmental disturbances in the fiber link. By extracting effective information through an adaptive filtering algorithm and aligning it with the synchronization signal's timestamp, distributed sensing with sub-meter spatial resolution is possible.

[0069] Optionally, the precision sensing control unit is used to perform closed-loop control on the frequency of the continuous light laser according to the digital sensing signal.

[0070] Optionally, the precision sensing control unit is further configured to perform closed-loop control on the amplification gain of the low-noise optical amplifier and the acquisition rate of the data processing unit according to the digital sensing signal.

[0071] Specifically, the precision sensing control unit can perform closed-loop control of the frequency of the continuous light laser, the amplification gain of the low-noise optical amplifier, and the acquisition rate of the data processing unit based on the digital sensing signal fed back by the data processing unit, ensuring a dynamic balance between sensing accuracy and communication performance.

[0072] It should be noted that the precision sensing control unit can also monitor optical fiber link loss in real time, adjust quantum signal power, and balance sensing sensitivity and quantum bit error rate.

[0073] The present application also provides another possible implementation of a quantum communication and sensing system based on synchronous signal multiplexing. Figure 4 This is a schematic diagram of another quantum communication and sensing system based on synchronous signal multiplexing provided in an embodiment of the present application. Figure 4 As shown, the quantum communication and sensing system also includes: a quantum key scheduling device, which is connected to the first key sensing control unit and is used to generate a quantum key scheduling control signal according to the security requirement instruction of the upper-layer device, and send it to the first key sensing control unit, so that the first key sensing control unit generates a quantum key generation control signal according to the key scheduling control signal and sends it to the quantum signal generation and negotiation device, so that the quantum signal generation and negotiation device generates a quantum key.

[0074] In this embodiment, the quantum key scheduling device is used to generate a quantum key scheduling control signal according to the security requirement instruction of the upper-layer device, and send it to the first security control unit, and then receive the quantum key sent by the first security control unit and send it to the upper-layer device.

[0075] Optionally, the quantum key scheduling device includes: a quantum key scheduling control unit, a management interface unit, and a key output unit.

[0076] Among them, the quantum key scheduling control unit is connected to the management interface unit to obtain security requirement instructions through the management interface unit. The quantum key scheduling control unit is also connected to the first secret control unit to obtain the quantum key generated by the quantum signal generation and negotiation device through the first secret control unit.

[0077] The quantum key scheduling control unit is also connected to the key output unit to send the quantum key to the upper-layer device through the key output unit.

[0078] Specifically, the management interface unit receives security requirement instructions (such as key type, key update mode, key update frequency, etc.) from the upper-layer device and sends them to the quantum key scheduling control unit. The quantum key scheduling control unit generates a quantum key scheduling control signal based on the security requirement instructions and sends it to the first secret sensing control unit. The first secret sensing control unit controls the first quantum key generation control unit to generate a quantum key based on the received control signal and temporarily stores it in the first secret sensing control unit. The first secret sensing control unit then sends the quantum key to the quantum key scheduling control unit. The key output unit outputs the quantum key to the upper-layer device on demand based on the received control instructions, thereby achieving secure distribution of quantum keys. The quantum key scheduling control module in the first secret sensing control unit dynamically allocates key resources through a priority scheduling algorithm and integrates quantum random number encryption functions to support real-time encrypted transmission of sensor data.

[0079] 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 sensing system based on synchronous signal multiplexing, characterized in that: The quantum communication and sensing system includes: a transmitting device and a receiving device, wherein the transmitting device includes: a first density sensing control unit, a quantum signal generation and negotiation device, a synchronization signal multiplexing device, and a combiner; the receiving device includes: a second density sensing control unit, a quantum signal reception and negotiation device, and a splitter; the splitter is connected to the splitter via an optical fiber link; The first density sensing control unit is communicatively connected to the quantum signal generation and negotiation device and the synchronization signal multiplexing device, respectively. The negotiation signal interface and the quantum signal interface of the quantum signal generation and negotiation device are connected to the combiner, respectively for receiving and sending negotiation signals and sending quantum signals; the sensing interface of the synchronization signal multiplexing device is connected to the combiner, for generating and sending synchronization signals multiplexed into sensing signals, and receiving backward Rayleigh scattered RBS optical signals of the synchronization signals as sensing signals; The second density sensing control unit is connected to the wave splitter via the quantum signal receiving and negotiation device; The synchronization signal multiplexing device includes: a precision sensing control unit, a synchronization signal generating unit, a circulator and a sensing signal receiving unit; The precision sensing control unit is connected to the first density sensing control unit, the precision sensing control unit is connected to the synchronization signal generating unit, the synchronization signal generating unit is further connected to the first end of the circulator, and is used to generate the synchronization signal and send it through the second end of the circulator; The synchronization signal generating unit is also connected to the sensing signal receiving unit to output a reference optical signal. The sensing signal receiving unit is also connected to the third end of the circulator, and is used to receive the RBS optical signal collected by the second end of the circulator through the third end, and generate a digital sensing signal based on the reference optical signal and the RBS optical signal. The sensing signal receiving unit is also connected to the precision sensing control unit to transmit the digital sensing signal to the precision sensing control unit.

2. The system according to claim 1, wherein: The quantum signal generation and negotiation device includes: a first quantum key generation control unit, a random number generator, a negotiation signal transceiver unit, and a quantum signal generation unit; The first quantum key generation control unit is connected to the first secret control unit, the first quantum key generation control unit is further connected to the random number generator, and the first quantum key generation control unit is further connected to the quantum signal generation unit for generating the quantum signal; The first quantum key generation control unit is also connected to the negotiation signal transceiver unit for transmitting and receiving the negotiation signal.

3. The system according to claim 1, wherein: The synchronization signal generating unit includes: an atomic clock reference source, a continuous light laser, a first optical coupler, and an acousto-optic modulator, wherein the atomic clock reference source is connected to an input end of the continuous light laser so that the continuous light laser generates a continuous light signal based on the atomic clock reference signal; The control end of the continuous light laser is connected to the precision sensor control unit, the output end of the continuous light laser is connected to the input end of the first optical coupler, the first output end of the first optical coupler is used to output the reference light signal, and the second output end of the first optical coupler is connected to the input end of the acousto-optic modulator, so that the first optical coupler divides the continuous light signal into a detection light signal and the reference light signal; the output end of the acousto-optic modulator is connected to the first end of the circulator, so that the acousto-optic modulator generates and outputs the synchronization signal based on the detection light signal.

4. The system according to claim 1, wherein: The sensing signal receiving unit includes: a low-noise optical amplifier, a second optical coupler, a balanced detector, and a data processing unit; the input end of the low-noise optical amplifier is connected to the third end of the circulator for collecting the RBS optical signal; the output end of the low-noise optical amplifier is connected to the first input end of the second optical coupler, so that the low-noise optical amplifier enhances the RBS optical signal; the second input end of the second optical coupler is connected to the synchronization signal generating unit for receiving the reference optical signal; The output end of the second optical coupler is connected to the input end of the balanced detector, so that the second optical coupler divides the enhanced RBS optical signal into two RBS optical signals based on the reference optical signal. The output end of the balanced detector is connected to the input end of the data processing unit, so that the balanced detector performs balanced detection on the two RBS optical signals and outputs the detection results to the data processing unit. The output end of the data processing unit is connected to the precision sensing control unit, so that the data processing unit processes the detection results and outputs the digital sensing signal to the precision sensing control unit.

5. The system according to claim 3, wherein: The precision sensing control unit is used to perform closed-loop control on the frequency of the continuous light laser according to the digital sensing signal.

6. The system according to claim 4, characterized in that The precision sensing control unit also performs closed-loop control on the amplification gain of the low-noise optical amplifier and the acquisition rate of the data processing unit according to the digital sensing signal.

7. The system according to claim 1, wherein: The quantum communication and sensing system also includes: a quantum key scheduling device, which is connected to the first key sensing control unit and is used to generate a quantum key scheduling control signal according to the security requirement instruction of the upper-layer device, and send it to the first key sensing control unit, so that the first key sensing control unit generates a quantum key generation control signal according to the key scheduling control signal and sends it to the quantum signal generation and negotiation device, so that the quantum signal generation and negotiation device generates a quantum key.

8. The system according to claim 7, characterized in that The quantum key scheduling device includes: a quantum key scheduling control unit, a management interface unit and a key output unit; The quantum key scheduling control unit is connected to the management interface unit to obtain the security requirement instruction through the management interface unit, and the quantum key scheduling control unit is also connected to the first secret control unit to obtain the quantum key generated by the quantum signal generation and negotiation device through the first secret control unit; The quantum key scheduling control unit is also connected to the key output unit to send the quantum key to the upper-layer device through the key output unit.

9. The system according to claim 2, wherein: The quantum signal generation unit includes: a pulse laser, a decoy state modulation unit, a quantum state modulation unit, and a signal power adaptation unit. The pulse laser is connected to the input end of the decoy state modulation unit to output a pulse laser to the decoy state modulation unit. The output end of the decoy state modulation unit is connected to the input end of the quantum state modulation unit, so that the decoy state modulation unit switches the pulse laser to obtain a decoy state coded signal. The output end of the quantum state modulation unit is connected to the input end of the signal power adaptation unit, so that the quantum state modulation unit encodes the decoy state coded signal to obtain the quantum signal to be attenuated. The output end of the signal power adaptation unit is connected to a combiner for attenuating the quantum signal to be attenuated, obtaining and outputting the quantum signal.

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