Dynamic user quantum communication system based on polarization selection
By introducing optical switch combinations into the quantum communication system, polarization selection based on phase coding is realized, which solves the problem of inflexible user switching in traditional systems, reduces the complexity and cost of system adjustment, and improves the flexibility and efficiency of the system.
Patent Information
- Application Number
- CN202423310831.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-11-28
- Estimated Expiration
- 2034-12-31
AI Technical Summary
Traditional quantum communication systems lack flexibility and cannot meet the dynamic communication needs of multiple users switching freely. The system adjustment complexity and cost are high.
A phase-coded polarization-selective user quantum communication system is adopted. By using a combination of a first optical switch and a second optical switch, one-to-one and one-to-many user switching can be achieved through optical path adjustment, reducing the system adjustment complexity and cost.
It enables easy addition or replacement of users without reconfiguring the network, reducing the complexity and cost of system adjustments and improving the system's flexibility and efficiency.
Smart Images
Figure CN223613344U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of quantum communication and quantum network, and particularly relates to a dynamic user quantum communication system based on polarization selection. BACKGROUND
[0002] Quantum communication is a new technology that uses quantum mechanics to transmit information. Compared with traditional communication methods, quantum communication has higher security, especially in preventing eavesdropping and information leakage. Quantum Key Distribition (QKD) is a representative technology in quantum communication and quantum network applications, which uses the uncertainty principle in quantum mechanics to ensure the security of key transmission.
[0003] The quantum signals of quantum communication pass through certain paths during transmission, which can be optical fibers, free space (such as satellite-to-ground communication), or other media that can carry quantum states. In quantum communication, quantum states (such as qubits) are transmitted through these fixed paths, usually modulated with phase, polarization, and other optical degrees of freedom to load information, to achieve information encryption or transmission. With the development of quantum communication technology, how to achieve efficient and flexible quantum information transmission in complex network environments has become an important research direction. Traditional quantum communication systems usually use fixed paths for information transmission, which is simple but lacks flexibility and cannot meet the needs of dynamic communication with multiple users freely switching.
[0004] Therefore, it is necessary to improve the prior art and propose a quantum communication system based on polarization selection of users with phase encoding, which reduces the complexity and cost of system adjustment. SUMMARY
[0005] To solve the above technical problems, a quantum communication system based on polarization selection of users with phase encoding is proposed, which reduces the complexity and cost of system adjustment.
[0006] To achieve the above purpose, the technical solution adopted by the present application is as follows: a dynamic user quantum communication system based on polarization selection, comprising a sending end Alice and a plurality of receiving ends Bob, the plurality of receiving ends Bob being a first receiving end Bob1, a second receiving end Bob2, a third receiving end Bob3, …, and an Nth receiving end Bobn, wherein;
[0007] The sending end Alice is connected with the first receiving end Bob1; the first receiving end Bob1, the second receiving end Bob2, the third receiving end Bob3, …, and the Nth receiving end Bobn are sequentially connected in order;
[0008] The sending end Alice is used for sending a phase-modulated pulse signal to any one of the first receiving end Bob1 or the plurality of receiving ends Bob.
[0009] After receiving the pulse signal, any receiving end Bob receiving the pulse signal receives the pulse signal, and the pulse signal is returned to the Alice end along the original route after being phase-modulated, polarization-compensated, and reflected by a fiber delay.
[0010] Preferably, the receiving end Bob includes a first optical switch and a second optical switch, and the first optical switch and the second optical switch each include three paths.
[0011] The three paths of the first optical switch are a first path, a second path, and a third path.
[0012] The three paths of the second optical switch are a fourth path, a fifth path, and a sixth path.
[0013] Preferably, the sending end Alice is connected to the receiving end Bob through the first path of the first optical switch of any receiving end Bob; the first optical switch of any receiving end Bob is connected to the second optical switch, and the sixth path of the second optical switch of the previous receiving end Bob is connected to the first optical switch of the next adjacent receiving end Bob.
[0014] Preferably, the pulse signal of the sending end Alice is connected into the first receiving end Bob1 through the first path of the first optical switch.
[0015] Or the pulse signal of the sending end Alice is connected to the second optical switch of the first receiving end Bob1 through the third path of the first optical switch, and the sixth path of the second optical switch of the first receiving end Bob1 is connected to the first path of the first optical switch of the second receiving end Bob2 to enter the second receiving end Bob2.
[0016] Or the pulse signal of the sending end Alice is connected to the second optical switch of the second receiving end Bob2 through the third path of the first optical switch of the second receiving end Bob2, and the sixth path of the second optical switch of the second receiving end Bob2 is connected to the first path of the first optical switch of the third receiving end Bob3 to enter the third receiving end Bob3.
[0017] By analogy, the pulse signal of the sending end Alice enters the Nth receiving end Bobn.
[0018] Preferably, any receiving end Bob includes a first optical switch, a circulator, a Faraday rotator, a Sagnac ring device, a second optical switch, a fiber delay line, and a Faraday mirror.
[0019] The first path of the first optical switch is connected with a sending terminal Alice.
[0020] The second path of the first optical switch is sequentially connected with a circulator, a Faraday rotator and a Sagnac loop device.
[0021] The circulator is connected with a second optical switch through a fourth path of the second optical switch.
[0022] The third path of the first optical switch is connected with the second switch.
[0023] The fifth path of the second switch is sequentially connected with a fiber delay line and a Faraday mirror.
[0024] The sixth path of the second switch is connected with the first path of a first optical switch of a next receiving terminal Bob adjacent to the second switch.
[0025] Preferably, the Sagnac loop device is used for phase modulation of the pulse signal at the Bob terminal.
[0026] Preferably, the Faraday rotator is used for compensating for polarization change introduced by the Sagnac loop device.
[0027] Preferably, the fiber delay line is used for delaying the pulse signal to avoid collision between the pulse reflected by the Faraday mirror and the next pulse signal being transmitted.
[0028] Preferably, the Sagnac loop device comprises a beam splitter, a phase modulator and a Faraday rotator, and the beam splitter, the phase modulator and the Faraday rotator are sequentially connected in a ring shape.
[0029] The present application has the beneficial technical effects that: the present application sets the first optical switch and the second optical switch in the system, and the cooperation of the two optical switches can increase or replace users, and the adjustment of the optical path by the two optical switches can easily realize 1 to 1, 1 to many, and realize arbitrary selection of the receiving terminal, without the need to reconfigure the entire network, thereby reducing the complexity and cost of system adjustment. BRIEF DESCRIPTION OF DRAWINGS
[0030] Figure 1 It is a whole structure block diagram of a dynamic user quantum communication system based on polarization selection.
[0031] Figure 2 It is a structure schematic diagram of a Sagnac loop device of a dynamic user quantum communication system based on polarization selection. DETAILED DESCRIPTION
[0032] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below with examples, but the scope of the present application claimed is not limited to the following specific examples.
[0033] As shown in Figure 1 A dynamic user quantum communication system based on polarization selection, comprising a sending end Alice and a plurality of receiving ends Bob, the plurality of receiving ends Bob are respectively a first receiving end Bob1, a second receiving end Bob2, a third receiving end Bob3, …, and an Nth receiving end Bobn, wherein;
[0034] The sending end Alice is connected with the first receiving end Bob1 through an optical fiber; the first receiving end Bob1, the second receiving end Bob2, the third receiving end Bob3, …, and the Nth receiving end Bobn are sequentially connected through optical fibers;
[0035] The sending end Alice is used to send a phase-modulated pulse signal to the first receiving end Bob1 or any one of the plurality of receiving ends Bob;
[0036] After receiving the pulse signal, any receiving end Bob receiving the pulse signal performs phase modulation, polarization compensation, and reflected fiber delay on the pulse signal, and returns the processed pulse signal to the Alice end along the original route for detection.
[0037] Specifically, the detailed connection relationship between the sending end Alice and any one of the receiving ends Bob is as follows:
[0038] The receiving end Bob comprises a first optical switch 101 and a second optical switch 105, both of which comprise three paths,
[0039] The three paths of the first optical switch 101 are respectively a first path 1, a second path 2, and a third path 3;
[0040] The three paths of the second optical switch 105 are respectively a fourth path 4, a fifth path 5, and a sixth path 6.
[0041] The sending end Alice is connected with the receiving end Bob through the first path 1 of the first optical switch 101 of any receiving end Bob; the first optical switch 101 of any receiving end Bob is connected with the second optical switch 105, and the sixth path 6 of the second optical switch 105 of a previous receiving end Bob is connected with the first optical switch 101 of its next adjacent receiving end Bob.
[0042] After the pulse signal of the sending end Alice enters the receiving end Bob, it enters the first receiving end Bob1 through the first path 1 of the first optical switch 101 of the receiving end Bob.
[0043] Or the pulse signal of the sending end Alice is connected with the second optical switch 105 of the first receiving end Bob1 through the third path 3 of the first optical switch 101, and the sixth path 6 of the second optical switch 105 of the first receiving end Bob1 is connected with the first path 1 of the first optical switch 101 of the second receiving end Bob2 to enter the second receiving end Bob2;
[0044] Or the pulse signal of the sending end Alice is connected with the second optical switch 105 of the second receiving end Bob2 through the third path 3 of the first optical switch 101 of the second receiving end Bob2, and the sixth path 6 of the second optical switch 105 of the second receiving end Bob2 is connected with the first path 1 of the first optical switch 101 of the third receiving end Bob3 to enter the third receiving end Bob3;
[0045] By analogy, the pulse signal of the sending end Alice enters the Nth receiving end Bobn.
[0046] Specifically, the internal structure and connection relationship of any receiving end Bob are as follows:
[0047] Any receiving end Bob includes a first optical switch 101, a circulator 102, a Faraday rotator 103, a Sagnac ring device 104, a second optical switch 105, a fiber delay line 106 and a Faraday mirror 107;
[0048] The first path 1 of the first optical switch 101 is connected with the sending end Alice;
[0049] The second path 2 of the first optical switch 101 is sequentially connected with the circulator 102, the Faraday rotator 103 and the Sagnac ring device 104 in sequence;
[0050] The circulator 102 is connected with the second optical switch 105 through the fourth path 4 of the second optical switch 105;
[0051] The third path 3 of the first optical switch 101 is connected with the second optical switch 105;
[0052] The second optical switch 105 is sequentially connected with the fiber delay line 106 and the Faraday mirror 107 through the fifth path 5;
[0053] The sixth path 6 of the second optical switch 105 is connected with the first path 1 of the first optical switch 101 of the next receiving end Bob adjacent to it.
[0054] The functions of each device are as follows:
[0055] The Sagnac ring device 104 is used for phase modulation of the pulse signal entering the Bob end;
[0056] The Faraday rotator 103 is used to compensate the polarization change introduced by the Sagnac loop device 104.
[0057] The optical fiber delay line 106 is used to delay the pulse signal to avoid the collision between the pulse signal reflected by the Faraday mirror 103 and the next pulse signal being transmitted.
[0058] Specifically, the Sagnac loop device 104 comprises a beam splitter 201, a phase modulator 202 and a Faraday rotator 203, which are connected in sequence in a ring shape.
[0059] For the convenience of understanding, we describe two cases of communication between the sending end Alice and the receiving end Bob1 and the communication between the sending end Alice and the receiving end Bob2.
[0060] Communication case 1: the sending end Alice communicates with the receiving end Bob1:
[0061] First, the partially phase-modulated pulse signal generated by the sending end Alice is transmitted to Bob1, and the pulse signal enters the first path after the first optical switch 101, and then enters the second path 2 through the port of the first optical switch 101. After passing through the circulator 102, the pulse signal first enters the Faraday rotator 103, and then the Sagnac loop device 104 performs phase modulation at the Bob end. At this time, the pulse signal has the phase modulation information of Alice and Bob1, that is, the pulse signal contains the key information at this time. At this time, the pulse signal containing the key information comes out of the Sagnac loop device 104, enters the Faraday rotator 103 to compensate the polarization change caused by the Sagnac loop device, and then passes through the circulator 102 to the fourth path 4. At this time, because Alice selects the communication user Bob1, the pulse signal enters the second optical switch 105 through the fourth path 4, and then enters the fifth path 5 through the port of the second optical switch 105. After entering the path 5, the pulse signal first passes through the optical fiber delay line 106, and then passes through the Faraday mirror 107 to be reflected again through the optical fiber delay line 106. Finally, the pulse signal carrying the key information returns to the Alice end along the original path for detection.
[0062] The approximate process of the pulse signal carrying the key information returning along the original path is as follows:
[0063] The pulse signal enters the fourth path 4 through the second optical switch 105; after passing through the circulator 102, it goes to the second path 2, and then the pulse signal returns to the Alice end through the first path 1 of the first optical switch 101 for detection at the Alice end.
[0064] The pulse signal is detected at the Alice end using the existing quantum communication detection method, which is not the main point of the present application, and thus will not be described in detail.
[0065] Communication case 12: the sending end Alice communicates with the receiving end Bob2:
[0066] First, the partially phase-modulated pulse signal generated by the sending end Alice is transmitted to Bob1. After the pulse signal reaches the first optical switch 101, it is connected to the third path 3 through the port of the first optical switch 101, and the third path 3 is connected to the sixth path 6 of the second optical switch 105. The sixth path 6 is connected to the first path 1 of the first switch 101 of Bob2, and the pulse signal enters Bob2 through the first path 1 of the first switch 101 of Bob2. Similarly, the pulse signal is connected to the second path 2 through the port of the first optical switch 101 of Bob2, just like the communication between Alice and Bob1. After the pulse signal passes through the circulator 102 of Bob2, it first enters the Faraday rotator 103 of Bob2, and then passes through the Sagnac loop device 104 of Bob2 for phase modulation at the Bob end. At this time, the pulse signal has the phase modulation information of Alice and Bob2, i.e., the key information. After the pulse signal comes out of the Sagnac loop device 104 of Bob2, it enters the Faraday rotator 103 of Bob2 to compensate for the polarization change caused by the Sagnac loop device 104 of Bob2, and then passes through the circulator 102 of Bob2 to the fourth path 4. The pulse signal enters the second switch 105 through the fourth path 4, and then enters the fifth path 5 through the second switch 105. After entering the fifth path 5, the pulse signal first passes through the fiber delay line 106 of Bob2, and then passes through the Faraday mirror 107 of Bob2 to reflect and pass through the fiber delay line 106 again. The pulse signal returns to the Alice end along the original path for detection.
[0067] A quantum communication method based on phase encoding and polarization selection corresponding to the present system is as follows:
[0068] Step S1: the sending end Alice sends a phase-modulated pulse signal;
[0069] The pulse signal enters the receiving end Bob end in the following two ways:
[0070] The first way is:
[0071] Step S2-1: the pulse signal enters the first receiving end Bob1 through the first path 1 of the first switch 101, and enters the second path 2 of the first switch 101 of the receiving end Bob1;
[0072] Step S2-2: In the second path 2, the pulse signal enters the Faraday rotator 103 through the circulator 102, and then enters the Bob end phase modulation through the ring device 104 to obtain the key information.
[0073] Step S2-3: After the key information comes out of the Sagnac ring device 104, it enters the Faraday rotator 103 to compensate for the polarization change caused by the Sagnac ring device 104, and then enters the fourth path 4 of the second optical switch 105 through the circulator 102.
[0074] Step S2-4: From the fourth path 4 to the fifth path 5 of the second optical switch 105.
[0075] Step S2-5: In the fifth path 5, the key information enters the optical fiber delay line 106, and then is reflected back to the optical fiber delay line 106 through the Faraday mirror 107, and returns to the Alice end along the original path for detection.
[0076] The second way is:
[0077] Step S3-1: The pulse signal enters the third path 3 of the first receiving end Bob1 through the first switch 101 of the first receiving end Bob1, and then enters the sixth path 6 of the first receiving end Bob1 through the second optical switch 105 of the first receiving end Bob1.
[0078] Step S3-2: The pulse signal enters the first switch 101 of the second receiving end Bob2 from the sixth path 6 of the first receiving end Bob1, and then enters the second path 2 of the first switch 101 of the second receiving end Bob2 to realize the same signal processing operation as the first way.
[0079] Similarly, through the second way, the pulse signal can enter the Nth receiving end Bobn.
[0080] The present application sets the first optical switch and the second optical switch in the system, and through the cooperation of the two optical switches, the user can be increased or replaced, and through the adjustment of the optical path by the two optical switches, 1 to 1, 1 to many, and any selected receiving end can be easily realized, without the need to reconfigure the entire network, thereby reducing the complexity and cost of system adjustment.
[0081] According to the disclosure and teaching of the above description, those skilled in the art can also make changes and modifications to the above embodiments. Therefore, the present application is not limited to the specific embodiments disclosed and described above, and some modifications and changes of the application should also fall within the protection scope of the claims of the present application. In addition, although some specific terms are used in the present specification, these terms are only for convenience of description and do not constitute any limitation on the application.
Claims
1. A dynamic user quantum communication system based on polarization selection, characterized in that, Including a sending end Alice and a plurality of receiving end users Bob, a plurality of receiving ends Bob are respectively a first receiving end Bob1, a second receiving end Bob2, a third receiving end Bob3,..., and an N receiving end Bobn, wherein; The sending end Alice is connected with the first receiving end Bob1;The first receiving end Bob1, the second receiving end Bob2, the third receiving end Bob3,..., and the N receiving end Bobn are sequentially connected in order; The sending end Alice is used to send a phase modulated pulse signal to the first receiving end Bob1 or any one of the plurality of receiving ends Bob; Any receiving end Bob receiving the pulse signal receives the pulse signal, and the pulse signal is returned to the Alice end along the original route after being phase modulated, polarization compensated and reflected fiber delayed.
2. A dynamic user quantum communication system based on polarization selection according to claim 1, characterized in that, The receiving end Bob includes a first optical switch and a second optical switch, and the first optical switch and the second optical switch each include three paths, The three paths of the first optical switch are respectively a first path, a second path and a third path; The three paths of the second optical switch are respectively a fourth path, a fifth path and a sixth path.
3. A dynamic user quantum communication system based on polarization selection according to claim 2, characterized in that, The sending end Alice is connected with the receiving end Bob through the first path of the first optical switch of any receiving end Bob;The first optical switch of any receiving end Bob is connected with the second optical switch, and the sixth path of the second optical switch of the previous receiving end Bob is connected with the first optical switch of the next adjacent receiving end Bob.
4. A dynamic user quantum communication system based on polarization selection according to claim 3, characterized in that, The pulse signal of the sending end Alice is connected into the first receiving end Bob1 through the first path of the first optical switch; Or the pulse signal of the sending end Alice is connected with the second optical switch of the first receiving end Bob1 through the third path of the first optical switch, and the sixth path of the second optical switch of the first receiving end Bob1 is connected with the first path of the first optical switch of the second receiving end Bob2 to enter the second receiving end Bob2; Or the pulse signal of the sending end Alice enters the N receiving end Bobn through the above path through the third path of the first optical switch of the second receiving end Bob2 and the second optical switch of the second receiving end Bob2, and the sixth path of the second optical switch of the second receiving end Bob2 is connected with the first path of the first optical switch of the third receiving end Bob3 to enter the third receiving end Bob3; By analogy, the pulse signal of the sending end Alice enters the N receiving end Bobn.
5. A dynamic user quantum communication system based on polarization selection according to claim 4, characterized in that, Any receiving end Bob includes a first optical switch, a circulator, a Faraday rotator, a Sagnac ring device, a second optical switch, a fiber delay line and a Faraday mirror; The first path of the first optical switch is connected with the sending end Alice; The second path of the first optical switch is sequentially connected with the circulator, the Faraday rotator and the Sagnac ring device in order; The circulator is connected with the second optical switch through the fourth path of the second optical switch; The third path of the first optical switch is connected with the second optical switch; The second optical switch is sequentially connected with the fiber delay line and the Faraday mirror through the fifth path. The sixth path of the second optical switch is connected with the first path of the first optical switch of the next receiving end Bob adjacent thereto.
6. A dynamic user quantum communication system based on polarization selection as claimed in claim 5 wherein, The Sagnac ring device is used for phase modulation of the pulse signal at the Bob end.
7. A polarization selection based dynamic user quantum communication system as claimed in claim 6, wherein, The Faraday rotator is used for compensating the polarization change introduced by the Sagnac ring device.
8. A dynamic user quantum communication system based on polarization selection according to claim 7, characterized in that, The optical fiber delay line is used for delaying the pulse signal, so as to avoid collision between the pulse reflected by the Faraday mirror and the next pulse signal being transmitted.
9. A dynamic user quantum communication system based on polarization selection according to claim 8, characterized in that, The Sagnac ring device comprises a beam splitter, a phase modulator and a Faraday rotator, and the beam splitter, the phase modulator and the Faraday rotator are sequentially connected in a ring shape.