Quantum key distribution device and method based on soliton optical comb

Abstract

The invention relates to the technical field of quantum key distribution, in particular to a quantum key distribution device and method based on soliton optical combs. A soliton optical comb chip is used as a light source, the light source enters a quantum key coding chip, quantum state coding is achieved after pulse light generation, wavelength multiplexing, multi-quantum key protocol coding and light attenuation, and the light source is input to a multi-wavelength multi-path optical switching chip for path selection. After passing through the optical fiber channel, the signal light is input into the quantum key decoding chip to be decoded and detected. According to the invention, multiple users can use different protocols to carry out quantum key distribution, quantum states carrying different coding modes carry out quantum communication with different communication parties based on wavelength decoupling, and construction of a quantum communication network can be supported.

Description

Technical Field

[0001] The present invention relates to the technical field of quantum key distribution, and particularly relates to a quantum key distribution device and method based on a soliton optical comb. Background Technique

[0002] With the development of quantum computers and quantum algorithms, some existing cryptographic systems, especially public-key cryptographic systems, have been severely impacted and challenged. However, with the continuous development of quantum information technology, the maturity of quantum key distribution technology based on the basic principles of quantum mechanics provides security for cyberspace. Quantum key distribution can securely realize the key negotiation between communication parties, and combined with the one-time pad scheme, it can achieve information-theoretically absolutely secure confidential communication.

[0003] Quantum key distribution can be divided into discrete variable protocols and continuous variable protocols according to its encoding dimension. Discrete variable protocols can transmit long distances and their security has been fully demonstrated. Discrete variable quantum key distribution systems can now achieve key distribution beyond one thousand kilometers, and can achieve data transmission exceeding one hundred megabits at short distances. Quantum key distribution systems are currently developing towards networking and integration. Quantum communication based on trusted relays has realized the integration of free space and fiber optic networks. With the maturity of integrated unit devices, integrated quantum key distribution systems are also gradually moving towards fully integrated and networked systems.

[0004] In terms of the integration of quantum key distribution systems, the integration of system modulation modules has matured, and the encoding and decoding parts of protocols such as polarization, phase, and time phase can be integrated. However, the integration methods of light sources and single-photon detectors are still in the exploratory stage. How to construct a star-shaped quantum communication network centered on each user node through the integration of light sources and single-photon detectors has become a new research direction in the field of quantum key distribution for confidential communication. Summary of the Invention

[0005] Therefore, the present invention provides a quantum key distribution device and method based on a soliton optical comb to solve the problem that the integration of light sources and single-photon detectors in existing quantum key distribution systems is not ideal, which affects the application and deployment in confidential communication networks.

[0006] According to the design scheme provided by the present invention, on the one hand, a quantum key distribution device based on a soliton optical comb is provided, including:

[0007] A soliton optical comb chip for generating N wavelength channel light sources in the C band, where N≥2;

[0008] A quantum key encoding chip, which, as a transmitting end, modulates the light source generated by the soliton photonic crystal chip and encodes it into a quantum state to obtain a signal light after quantum state encoding;

[0009] An optical switching chip, which is used to select paths for the signal lights of each user transmitted through an optical fiber channel and distribute the signal lights to corresponding paths;

[0010] A quantum key decoding chip, which, as a receiving end, decodes each protocol signal light and performs quantum state detection to obtain a quantum key.

[0011] As a quantum key distribution device based on soliton optical comb of the present invention, further, the soliton photonic crystal chip includes: a pump light source and a double-layer silicon nitride waveguide microring resonator. The pump light source is obtained by using an on-chip external cavity laser, and the pump light is transmitted to the on-chip silicon nitride microring resonator through the silicon nitride waveguide in the on-chip external cavity laser, and continuous light with a wavelength number of N is generated in the C band by using the nonlinearity of the on-chip silicon nitride microring resonator under the temperature control of a semiconductor refrigerator.

[0012] As a quantum key distribution device based on soliton optical comb of the present invention, further, the quantum key encoding chip includes: a modulation module, a demultiplexing module, a multi-protocol encoding module, and an adjustable optical attenuation module. Among them, the modulation module is used to chop and modulate the light source through an on-chip cascaded intensity modulator in the time domain; the demultiplexing module is used to separate the light source in the waveguide by adjusting the resonance position of the microring array; the multi-protocol encoding module is used to encode information on the photon modulation by using a protocol encoding method, and the encoded optical pulse is selectively output to the waveguide through an optical switch; the adjustable optical attenuation module is used to attenuate the power of the encoded optical pulse to the single-photon level.

[0013] As a quantum key distribution device based on soliton optical comb of the present invention, further, the modulation module includes a three-stage Mach-Zehnder structure. Among them, the first-stage Mach-Zehnder structure uses a 1×2 multimode interference coupler to split the input light source into two paths. The two paths of light are respectively tuned by thermo-optic tunable phase shifters on the upper and lower arms and then input into a 2×2 multimode interference coupler. The output power ratio of the two ports is realized by adjusting the thermo-optic tunable phase shifter to ensure that the optical powers of the two output ports are the same; the second-stage intensity modulator intensity-modulates the light output by the first-stage Mach-Zehnder structure, and the intensity-modulated output light is then input into the third-stage modulator for secondary modulation, and pulsed light with a corresponding extinction ratio is output at the output port of the 2×1 multimode interference coupler.

[0014] As the quantum key distribution device based on soliton optical comb of the present invention, further, the demultiplexing module performs wavelength decomposition multiplexing of N-channel wavelength signals according to the number of participating nodes in the quantum key distribution network and by using micro-rings and waveguide arrays, and allocates point-to-point communication party wavelength channels in the wavelength decomposition multiplexing channels according to the participating node numbers of the network.

[0015] As the quantum key distribution device based on soliton optical comb of the present invention, further, the optical switching chip includes N input ports and N output ports, and realizes the routing selection of N-path inputs in the optical switching chip through an external power supply strategy.

[0016] As the quantum key distribution device based on soliton optical comb of the present invention, further, the quantum key decoding chip includes an optical switch, several protocol decoding units and a single-photon detection array. Among them, the optical switch is used to input the signal light into the corresponding protocol decoding unit according to the negotiation protocol between the communication parties, the protocol decoding unit is used to decode the signal light, and the single-photon detection array is used to detect the decoded signal light and obtain the quantum key.

[0017] On the other hand, the present invention also provides a quantum key distribution method based on soliton optical comb, including:

[0018] Generating N wavelength channel light sources in the C band by using a soliton optical frequency comb chip, where N≥2;

[0019] Modulating the light source generated by the soliton optical frequency comb chip and encoding it into a quantum state to obtain a signal light after quantum state encoding;

[0020] Performing path selection on the signal lights of each user transmitted through the optical fiber channel and allocating the signal lights to the corresponding optical fiber paths;

[0021] Decoding and quantum state detecting the signal light of the negotiation protocol between the communication parties to obtain the quantum key.

[0022] Advantages of the present invention:

[0023] The present invention uses a soliton optical comb chip as a light source. The light source is input into the quantum key encoding chip, and quantum state encoding is realized after pulse light generation, wavelength multiplexing, multiple quantum key protocol encodings and optical attenuation. Then it is input into a multi-wavelength multi-path optical switching chip for path selection. After the signal light passes through the optical fiber channel, it is input into the quantum key decoding chip to realize decoding and detection. It supports multiple users to perform quantum key distribution using different protocols, and carries quantum based on wavelength decoupling with different coding methods to perform quantum communication with different communication parties, which is beneficial to supporting the construction of a quantum communication network. Description of the Drawings

[0024] Figure 1Schematic diagram of the structure of the quantum key distribution device based on soliton optical comb in the embodiment;

[0025] Figure 2 Schematic diagram of the structure of the soliton optical comb chip in the embodiment;

[0026] Figure 3 Schematic diagram of the structure of the quantum key encoding chip in the embodiment;

[0027] Figure 4 Example of the demultiplexing module in the embodiment;

[0028] Figure 5 Example of the multi-wavelength module switching chip in the embodiment;

[0029] Figure 6 Schematic diagram of the structure of the quantum key decoding chip in the embodiment. Specific implementation manners

[0030] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and technical solutions.

[0031] An integrated soliton optical comb can realize a multi-wavelength light source at a relatively low cost. Since the characteristic of quantum key distribution lies in its point-to-point communication, an integrated wavelength division multiplexing system using an optical frequency comb can construct a star network centered on each user node at a lower cost, which is beneficial to the large-scale deployment of a quantum network communication system. In order to ensure the security of information transmission in the network, in view of the current situation of the development of quantum key distribution systems and integrated optical devices, in the embodiments of this case, a quantum key distribution device based on a soliton optical comb is provided, including:

[0032] A soliton optical sparse chip, which is used to generate N wavelength channel light sources in the C band, where N≥2;

[0033] A quantum key encoding chip, which, as a sending end, modulates and encodes the light source generated by the soliton optical sparse chip into a quantum state to obtain a signal light after quantum state encoding;

[0034] An optical switching chip, which is used to select the paths of the signal lights of each user transmitted through the optical fiber channel and distribute the signal lights to the corresponding paths;

[0035] A quantum key decoding chip, which, as a receiving end, decodes and performs quantum state detection on each protocol signal light and obtains a quantum key.

[0036] Such as Figure 1As shown, the optical part in the device is composed of chips, which can greatly reduce the volume of the device. Its structure consists of a soliton optical comb chip, a quantum key encoding chip, a multi-wavelength multi-path optical switching chip, and a quantum key decoding chip. The quantum key encoding chip is composed of a high extinction ratio pulsed light modulation module, a demultiplexing module, a multi-protocol encoding module, and an adjustable optical attenuation module. By means of the nonlinear effect of the double-layer silicon nitride waveguide microring resonator, an N-wavelength optical frequency comb can be obtained only after inputting a single-wavelength pump light, greatly reducing the cost of the light source in the integrated wavelength division multiplexing system. The quantum key encoding chip can realize the chopping of continuous light input, wavelength division demultiplexing, encoding of multiple quantum key distribution protocols, and single-photon attenuation of pulsed light. A single node can use N-channel signal lights of different wavelengths as carriers for N communication parties respectively. It can also be applicable to the encoding and decoding of multiple quantum key distribution protocols. There are N-channel signal lights of different wavelengths carrying M encoding methods at the output end of the quantum key encoding chip. These N-channel signals will be input into the multi-wavelength multi-path optical switching chip to realize the routing of each channel signal light in the integrated quantum key distribution network. After the path selection of the multi-wavelength multi-path optical switching chip, the signal light enters the optical fiber channel and will be received by the receiving-end chip. After the signal light enters the receiving-end chip, it first enters the optical switch to select a set protocol for path selection and decoding. The signal light output by the decoding module will be detected by a single-photon detector to complete the key negotiation between the two communication parties of point-to-point communication, ensuring the information transmission security of the secure communication network. Among them, the quantum key encoding chip, the multi-wavelength multi-path optical switching chip, and the quantum key decoding chip are all fabricated on silicon-on-insulator wafers.

[0037] Among them, the soliton optical comb chip is used to generate continuous light with a wavelength number N (N≥2), such as Figure 2 shown, which includes a pump light source and a double-layer silicon nitride waveguide microring resonator. Among them, the pump light source can be realized by an on-chip external cavity laser. The external cavity laser has wide wavelength tunability, and the center wavelength of the pump light can be adjusted by adjusting the voltage of the silicon nitride external cavity micro-ring. The pump light is input into the double-layer silicon nitride waveguide microring resonator through the silicon nitride waveguide in the external cavity laser. Under the temperature control of the thermoelectric cooler, an optical frequency comb with a line spacing of about 100 GHz can be generated in the C band by using the nonlinear effect of the microring resonator.

[0038] such as Figure 3As shown, the quantum key encoding chip can be designed to include: a modulation module, a demultiplexing module, a multi-protocol encoding module and an adjustable optical attenuation module, wherein the modulation module is used to chop and modulate the light source in the time domain through an on-chip cascade intensity modulator; the demultiplexing module is used to separate the light source in the waveguide by adjusting the resonance position of the microring array; the multi-protocol encoding module is used to encode information on photon modulation using a protocol coding method, and select the encoded light pulses to be output to the waveguide through an optical switch; the adjustable optical attenuation module is used to attenuate the power of the encoded light pulse to the single photon level.

[0039] The high extinction ratio pulse light modulation module is used to chop continuous light in the time domain to generate high extinction ratio pulse light. Continuous light chopping is achieved through a Mach-Zehnder structure thermo-optical modulator and two intensity modulators. The continuous light is input into the Mach-Zehnder structure to balance the optical power input to the two arms of the modulator. The light first enters the 1×2 multimode interference coupler MMI to split the light into two parts. The two paths of light pass through the thermo-optical tunable phase shifter TOP of the upper and lower arms respectively and are input into the 2×2 multimode interference coupler MMI. The output power ratio of the two arms can be achieved by adjusting the DC voltage applied to the thermo-optical tunable phase shifter TOP to balance the optical power output from the two arms of the MMI. The output light of the MMI enters the Mach-Zehnder structure intensity modulator MOD. The phase difference between the upper and lower arms is adjusted by adjusting the AC signal loaded on the intensity modulator. The interference destructive at the multimode interference coupler realizes two cascade intensity modulations. Finally, multi-wavelength high extinction ratio pulse light is output at the output port of the 2×1 multimode interference coupler MMI. The intensity modulation of the entrapped state is realized by an intensity modulator, which is composed of a Mach-Zehnder structure intensity modulator. The light first enters the 1×2 multimode interference coupler MMI to split the light into two parts and enter the intensity modulator MOD. The upper and lower arms are phase modulated by loading AC signals to achieve intensity modulation, respectively according to the probabilities P1, P2…, P k Randomly modulate k intensities A1, A2, ...A k The pulse light is output from the 2×1 multimode interference coupler MMI, thereby realizing the function of a high extinction ratio pulse light modulation module. The high extinction ratio pulse light intensity encoding is used for high extinction ratio pulse light modulation of multi-level decoy states (level number ≥ 2).

[0040] The demultiplexing module realizes the wavelength division multiplexing of N wavelength signals according to the number of participating nodes in the quantum key distribution network and utilizes micro-rings and waveguide arrays, and allocates wavelength channels for point-to-point communication within the wavelength division multiplexing channel according to the network participating node numbers.

[0041] like Figure 4As shown, the demultiplexing module implements the function of optical wave decomposition and multiplexing. It consists of a bus waveguide, N pairs of cascaded micro-rings, and N output waveguides. The optical signal first enters the waveguide and passes through the demultiplexing structure, which can separate the individual wavelengths of the optical frequency comb teeth and output them through the output waveguides from ports Out1, Out2, … Out N Output.

[0042] When the quantum key distribution system network is working, the control process of the demultiplexing module can be summarized as follows:

[0043] Step1: The communication users of the quantum key distribution system network are numbered according to the time of entering the network when accessing the network. The nodes that need to participate send signals to each other through the classical channel to confirm their participation in the network communication.

[0044] Step2: According to the signals received through the classical channel by the participating network nodes, when the demultiplexing module receives n classical signals, it indicates that the number of network participating nodes is n + 1. At this time, the demultiplexing module determines the power-on strategy according to the number of participating nodes, and realizes that the wave decomposition and multiplexing channels for n-channel wavelength signals are respectively (C1, C2, …, C n );

[0045] Step3: Allocate the wavelength channels of the point-to-point communication parties in the channel according to the node numbers, that is, allocate the wavelength channels in ascending order of the sum of the two parties' numbers.

[0046] Step4: When m new nodes join the network, these m new nodes send broadcast signals through the classical channel. The current participants in the quantum network that receive the signal send feedback signals to the new nodes and change the power-on strategy of the demultiplexing module to generate n + m (C1, C2, …, C n+m ) wavelength channels;

[0047] Step5: The channel allocation of the new nodes does not occupy the wavelengths used by the original nodes, so it does not affect the quantum communication of the initial n + 1 nodes. C1, C2, …, C n+m The channels are allocated according to the steps of Step2 and Step3 to realize the increase of quantum network nodes;

[0048] Step6: When l quantum network nodes withdraw, the used wavelength channels remain unchanged, and the demultiplexing module reduces the demultiplexing of l-channel wavelengths.

[0049] The above demultiplexing module can be implemented by a micro-ring and waveguide array or a Mach-Zehnder interferometer structure. After the quantum key distribution system confirms the number of nodes n + 1 participating in the communication in the network, a working voltage will be applied to n groups of cascaded micro-rings, and the corresponding wavelength pulses will be separated from the bus waveguide to the demultiplexing module outlet (Out1, Out2, …, Outn ) to separate the light of N wavelength channels through the thermal tuning of N on-chip microrings, and each separated channel is respectively output to a multi-protocol encoding module.

[0050] The multi-protocol encoding module is used to realize the selectivity of the system encoding protocol. The multi-protocol encoding module consists of two 1×M optical switches and M encoding modules. Single-wavelength pulsed light is input into the 1×M optical switch, and the user selects a protocol to modulate the pulsed light. The light enters the i-th encoding module to modulate the selection basis and encoding information, and finally enters the M×1 optical switch to output the light.

[0051] When single-wavelength pulsed light is input into the multi-protocol encoding module, it first enters the 1×M optical switch for path selection. Different encoding methods of different protocols can be selected by choosing the path. The single-wavelength pulsed light enters the encoding module to modulate the encoding information of the photons in each pulse. Finally, the optical pulse is output to the waveguide through the optical switch. Among them, the high extinction ratio pulsed light intensity encoding in the multi-protocol encoding module can be realized by cascading intensity modulators with Mach-Zehnder structures integrated with thermal tuning phase shifters on both arms. The multi-protocol encoding module can include M protocol encoding methods such as intensity encoding, phase encoding, polarization encoding, and time-phase encoding.

[0052] The tunable optical attenuation module is used to attenuate the optical pulse power to the single-photon level. This module is based on two cascaded Mach-Zehnder structures and realizes the attenuation of the optical power by integrating thermo-optical tunable phase shifters on both arms. The light output from the multi-protocol encoding module enters a 1×2 multimode interference coupler (MMI) and is split into two paths. The two paths of light respectively pass through the thermo-optical tunable phase shifters (TOP) on the upper and lower arms and then enter a 2×2 multimode interference coupler (MMI). The phase difference is adjusted by adjusting the DC voltage applied to the thermo-optical tunable phase shifters (TOP) on both arms, and interference cancellation occurs at the 2×2 multimode interference coupler (MMI) to achieve optical attenuation. Tunable attenuation of light can be achieved by cascading the same structure. When the output optical power reaches the single-photon intensity, it is output to the quantum key encoding chip.

[0053] As Figure 5 shown, the optical switching chip includes N input ports and N output ports, and realizes the routing selection of N-path input in the optical switching chip through an external power supply strategy.

[0054] The multi-wavelength multi-path optical switching chip is used to realize the routing of different single-wavelength pulsed lights in the quantum network communication system, satisfy the path selection of L×L for N wavelengths, and can realize the path connection between a user and other L nodes. The key is distributed through different wavelength channels between each node. N paths of different wavelength pulsed lights are input into the multi-wavelength optical switching chip through N ports. Routing selection can be realized for the N-path input in the optical switching chip through external power supply, and finally output at the N output ports.

[0055] According to the wavelength channel settings of the demultiplexing module, the control process of the multi-wavelength multi-path optical switching chip can be summarized as follows:

[0056] Step1: The network nodes of the quantum key distribution system are determined according to the corresponding optical fiber links of the current participating nodes in the network. Assume that there are n + 1 node users in the network, and each user needs to use n wavelength channels. These n channels (C1, C2,..., C n ) are respectively input into n entrances (In1, In2,..., In n ) of the optical switching chip in sequence;

[0057] Step2: The multi-wavelength multi-path optical switching chip determines the power-on strategy according to the actual optical fiber physical link, so that the n-channel input signals are respectively output to the wavelength channels allocated by the demultiplexing module for both sides of the quantum communication nodes;

[0058] Step3: When m new nodes join the network, the paths of the new nodes will not interfere with the existing paths. These m new nodes respectively input from (In n+1 , In n+2 , …, In n+m ) into the optical switching chip, and set the power-on strategy of the optical switching chip according to the optical fiber paths connected between the actual nodes;

[0059] Step4: When l nodes exit the network, the paths of the l exiting nodes will not interfere with the existing path settings, and the optical switching chip changes the power-on strategy.

[0060] As Figure 6 shown, the quantum key decoding chip includes an optical switch, several protocol decoding units and a single-photon detection array. Among them, the optical switch is used to input the signal light into the corresponding protocol decoding unit according to the negotiation protocol between the two communication parties. The protocol decoding unit is used to decode the signal light, and the single-photon detection array is used to detect the decoded signal light and obtain the quantum key.

[0061] The quantum key decoding chip receives the signal light from the optical fiber for decoding and detection. After the signal light is edge-coupled into the waveguide, the optical switch selects the corresponding decoding module according to the encoding protocol of the sender and performs detection.

[0062] Furthermore, based on the above system, the embodiment of the present invention also provides a quantum key distribution method based on soliton optical comb, including:

[0063] Generating N wavelength channel light sources in the C band by using a soliton optical comb chip, where N ≥ 2;

[0064] Modulating the light source generated by the soliton optical comb chip and encoding it into a quantum state to obtain a signal light after quantum state encoding;

[0065] Select the paths of the optical signals of each user transmitted through the optical fiber channel and allocate the optical signals to the corresponding optical fiber paths;

[0066] Decode the optical signals of the negotiation protocol between the two communication parties and perform quantum state detection to obtain quantum keys.

[0067] Unless otherwise specifically stated, the relative steps, numerical expressions, and numerical values of the components and steps set forth in these embodiments do not limit the scope of the present invention.

[0068] The various embodiments in this specification are described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method part.

[0069] The units and method steps of the various examples described in combination with the embodiments disclosed herein can be implemented by optical devices, electronic hardware, computer software, or a combination of the three. To clearly illustrate the interchangeability of hardware and software, the composition and steps of the various examples have been generally described according to functions in the above description. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Those of ordinary skill in the art can use different methods to implement the described functions for each specific application, but such implementation is not considered to exceed the scope of the present invention.

[0070] Those of ordinary skill in the art can understand that all or part of the steps in the above methods can be completed by instructing relevant hardware through a program. The program can be stored in a computer-readable storage medium, such as a read-only memory, a magnetic disk, or an optical disc, etc. Optionally, all or part of the steps of the above embodiments can also be implemented using one or more integrated circuits. Correspondingly, the various modules / units in the above embodiments can be implemented in the form of hardware or in the form of software function modules. The present invention is not limited to any specific form of the combination of hardware and software.

[0071] Finally, it should be noted that the above-described embodiments are only specific embodiments of the present invention, used to illustrate the technical solutions of the present invention, rather than limiting it. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that any technician familiar with the technical field of the present invention can still modify the technical solutions recorded in the foregoing embodiments or easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. A quantum key distribution device based on a soliton optical comb, characterized in that, Comprising: An optical soliton low-index chip, which serves as a light source for generating N wavelength channels in the C band, where N ≥ 2; A quantum key encoding chip, which serves as a transmitting end, modulates and encodes the continuous light generated by the optical soliton low-index chip into a quantum state to obtain a signal light after quantum state encoding; An optical switching chip, which is used to select the paths of the user signal lights transmitted through the optical fiber channels and distribute the signal lights to the corresponding paths; A quantum key decoding chip, which serves as a receiving end, decodes and performs quantum state detection on each protocol signal light and obtains the quantum key.

2. The quantum key distribution device based on a soliton optical comb according to claim 1, wherein The optical soliton low-index chip comprises: a pump light source and a double-layer silicon nitride waveguide microring resonator. Under the temperature control of a semiconductor refrigerator, the pump light source is realized by an on-chip external cavity laser and the pump light is transmitted to the on-chip silicon nitride microring resonator by using a double-layer silicon nitride waveguide, so as to generate continuous light with the number of wavelengths being N in the C band by using the nonlinearity of the on-chip silicon nitride microring resonator.

3. The quantum key distribution device based on a soliton optical comb according to claim 1, characterized in that The quantum key encoding chip includes: a modulation module, a demultiplexing module, a multi-protocol encoding module, and an adjustable optical attenuation module. Among them, the modulation module is used to chop and modulate the light source through an on-chip cascaded intensity modulator in the time domain; the demultiplexing module is used to separate the light source in the waveguide by adjusting the resonant position of the microring array; the multi-protocol encoding module is used to encode information on the photon modulation by using a protocol encoding method, and the encoded optical pulses are selectively output to the waveguide through an optical switch; the adjustable optical attenuation module is used to attenuate the power of the encoded optical pulses to the single-photon level.

4. The quantum key distribution device based on a soliton optical comb according to claim 3, wherein The modulation module comprises a three-stage Mach-Zehnder structure. Among them, the first-stage Mach-Zehnder structure uses a 1×2 multimode interference coupler to split the input light source into two paths. The two paths of light are respectively tuned by thermo-optic tunable phase shifters on the upper and lower arms and then input into a 2×2 multimode interference coupler. The output power ratio of the two ports is realized by adjusting the thermo-optic tunable phase shifter to ensure that the optical powers of the two output ports are the same; the second-stage intensity modulator modulates the output light of the first-stage Mach-Zehnder structure, and the intensity-modulated output light is then input into the third-stage modulator for secondary modulation, and pulsed light with a corresponding extinction ratio is output at the output port of the 2×1 multimode interference coupler.

5. The quantum key distribution device based on a soliton optical comb according to claim 3, wherein The demultiplexing module realizes the wavelength demultiplexing of N-channel signals by using a cascaded microring resonator array and a bus waveguide according to the number of participating nodes in the quantum key distribution network, and distributes the point-to-point communication party wavelength channels in the wavelength demultiplexing channel according to the network participating node numbers.

6. The quantum key distribution device based on a soliton optical comb according to claim 1, characterized in that, The optical switching chip comprises N input ports and N output ports, and realizes the routing selection of N-path inputs in the optical switching chip through an external power-on strategy.

7. The quantum key distribution device based on a soliton optical comb according to claim 1, characterized in that The quantum key decoding chip includes an optical switch, several protocol decoding units, and a single-photon detection array. Among them, the optical switch is used to input the signal light into the corresponding protocol decoding unit according to the negotiation protocol between the communication parties. The protocol decoding unit is used to decode the signal light, and the single-photon detection array is used to detect the decoded signal light and obtain the quantum key.

8. A quantum key distribution method based on a soliton optical comb, characterized in that, The implementation based on the system described in claim 1 includes the following steps: Using a soliton photonic crystal fiber chip to generate N wavelength channel light sources in the C band, where N ≥ 2; Modulating the continuous light generated by the soliton photonic crystal fiber chip and encoding it into a quantum state to obtain the signal light after quantum state encoding; Selecting the paths of the signal lights of each user transmitted through the optical fiber channel and allocating the signal lights to the corresponding optical fiber paths; Decoding and performing quantum state detection on the signal lights of the negotiation protocol between the two communication parties to obtain quantum keys.

9. An electronic device, characterized in that, It includes: At least one processor, and a memory coupled to the at least one processor; Wherein, the memory stores a computer program, and the computer program can be executed by the at least one processor to execute the method described in claim 8, or to run the system described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, A computer program is stored in the computer-readable storage medium. When the computer program is executed, it implements the system described in any one of claims 1 to 7, or runs the method described in claim 8.

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