CN105897413B - Sagnac loop-based phase modulation polarization encoded QKD system - Google Patents
Sagnac loop-based phase modulation polarization encoded QKD system Download PDFInfo
- Publication number
- CN105897413B CN105897413B CN201610362025.5A CN201610362025A CN105897413B CN 105897413 B CN105897413 B CN 105897413B CN 201610362025 A CN201610362025 A CN 201610362025A CN 105897413 B CN105897413 B CN 105897413B
- Authority
- CN
- China
- Prior art keywords
- polarization
- polarized light
- light
- beam splitter
- optical
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
- H04L9/0819—Key transport or distribution, i.e. key establishment techniques where one party creates or otherwise obtains a secret value, and securely transfers it to the other(s)
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
- H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
- H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
- H04L9/0852—Quantum cryptography
- H04L9/0858—Details about key distillation or coding, e.g. reconciliation, error correction, privacy amplification, polarisation coding or phase coding
Landscapes
- Engineering & Computer Science (AREA)
- Computer Security & Cryptography (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Theoretical Computer Science (AREA)
- Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)
- Optical Communication System (AREA)
Abstract
The invention discloses a phase modulation polarization coding QKD system based on a sagnac loop; the horizontal polarized light and the vertical polarized light are respectively transmitted in the polarization maintaining optical fiber along the clockwise direction and the anticlockwise direction; the horizontally polarized light reaches the polarization beam splitter PBS1; the vertically polarized light reaches the polarization beam splitter PBS1; the horizontal polarized light and the vertical polarized light are converged by the PBS1, then are emitted to the optical attenuator VOA through the optical circulator Cir1 and are attenuated to the single photon level by the optical attenuator VOA, so that the safe transmission on a channel is ensured. And then the light emitted by the synchronous light Laser _ S is combined to a common channel through a wavelength division multiplexer WDM. After the base selection is carried out by a polarization controller (PC 3), two groups of bases with orthogonal polarization directions are separated by a polarization beam splitter PBS3, and the detection and counting are carried out by a single photon detector. In a word, the invention has the advantages of good stability, simple structure and low cost.
Description
Technical Field
The invention relates to a quantum key distribution system based on polarization characteristics of optical photons, in particular to a phase modulation polarization coding QKD system based on a sagnac loop.
Background
The quantum cryptography is an encryption technology which is proved to be absolutely safe physically based on the Heisenberg inaccurate measurement principle and the theorem that a single quantum cannot be cloned. Based on the absolute safety, the technology has good application prospect in the aspects of military affairs, commerce, bank systems and the like. Polarization is one of basic physical quantities of light quantum, is an important resource which can be used for realizing quantum information technology, realizes effective utilization of the light quantum, and has important significance for the development of the quantum information technology. Quantum key distribution systems (QKD) based on the polarization properties of light quanta are also currently very common and innovative quantum cryptography systems are constantly being improved.
At present, the quantum cryptography technology enters a practical stage, and the stability, the integration and the economy of a quantum cryptography system are the problems which need to be concerned and solved currently. The stability includes the stability (temperature drift, vibration, change of polarization state and the like) of each module in the system operation, and the integration and the economical consideration are optical devices and hardware control modules with higher cost used by a transmitting end and a receiving end in the system, so that the system is more stable and portable by using the saved cost on the premise of not changing the principle and the safety.
Disclosure of Invention
The invention aims to provide a phase modulation polarization coding QKD system based on a sagnac loop, aiming at the defects of the prior art, and the phase modulation polarization coding QKD system based on the sagnac loop has the advantages of good stability, simple structure and low cost.
In order to achieve the technical purpose, the technical scheme adopted by the invention is as follows: a sagnac loop based phase modulated polarization encoded QKD system; the system comprises a transmitting end Alice and a receiving end Bob; the transmitting end Alice and the receiving end Bob are in European connection through an optical fiber channel; the method is characterized in that: the transmitting end Alice comprises a Laser _ Q, a Laser _ S, a polarization controller PC1, an optical circulator Cir, an optical attenuator VOA, a wavelength division multiplexer WDM and a transmitting end sagnac ring; the transmitting end sagnac ring comprises a polarization beam splitter PBS1, a phase modulator PMA, an optical rotator rotor 1 and a Delay1; polarization maintaining optical fibers are sequentially adopted among the polarization beam splitter PBS1, the phase modulator PMA, the optical rotator rotor 1 and the Delay1 to be connected in series, and the Delay1 and the polarization beam splitter PBS1 are also connected by the polarization maintaining optical fibers; the phase modulator PMA is used for adjusting single polarization; the Laser _ Q and the Laser _ S are used for generating pulsed light, and the pulsed light generated by the Laser _ Q is used as a quantum signal for system coding to generate a secret key; pulsed light generated by the Laser _ S is used as synchronous light and is used for synchronizing signals at two ends of the system; the polarization controller PC1 is used for converting the quantum optical signal into 45-degree linearly polarized light and emitting the linearly polarized light into the polarization beam splitter PBS1; the polarization beam splitter PBS1 is used for splitting 45-degree linearly polarized light into horizontal polarized light and vertical polarized light, and the horizontal polarized light and the vertical polarized light are respectively transmitted in the polarization maintaining optical fiber along clockwise direction and anticlockwise direction; the horizontal polarized light sequentially passes through a phase modulator PMA, a delayer 1 and a rotator1 to reach a polarization beam splitter PBS1; the vertically polarized light sequentially passes through a rotator1, a delayer 1 and a phase modulator PMA to reach a polarization beam splitter PBS1; the optical rotator1 is used for rotating the horizontal polarized light propagating clockwise by 90 degrees into vertical polarized light and rotating the polarization of the vertical polarized light propagating counterclockwise by 90 degrees into horizontal polarized light; the Delay1 is used for delaying the waiting time, wherein the waiting time is the waiting time required by modulating the phase, namely the clockwise or anticlockwise phase of the polarized light which is required by modulating the phase and is transmitted clockwise or anticlockwise, and the waiting time required by the other direction is only required by modulating the phase; the phase modulator PMA is used to modulate the phase of polarized light in a clockwise or counterclockwise direction; the horizontal polarized light and the vertical polarized light are converged by PBS1, then are emitted to an optical attenuator VOA through an optical circulator Cir and are attenuated to set light intensity by the optical attenuator VOA, then are multiplexed and combined to a common channel with light emitted by a Laser _ S through a wavelength division multiplexer WDM, and then are transmitted to a receiving end Bob through an optical fiber channel;
the receiving end Bob comprises a strong light Detector, a wavelength division multiplexer DWDM, a single photon Detector SPD, a polarization controller PC2, a polarization controller PC3, an optical circulator Cir, a polarization beam splitter PBS3 and a receiving end sagnac ring; the receiving end sagnac loop comprises a polarization beam splitter PBS2, a phase modulator PMB, an optical rotator rotor 2 and a Delay2; after the optical pulse reaches a receiving end Bob, the optical pulse is demultiplexed by a wavelength division multiplexer DWDM, namely, split light is obtained, synchronous light and quantum light are respectively transmitted along different paths, and the synchronous light is detected by a strong light Detector to realize photoelectric conversion for system synchronization; the quantum light pulse is rectified by a polarization controller PC2 and then enters a sagnac ring of a receiving end Bob through a circulator Cir, the working mode of each optical device in the sagnac ring of the receiving end Bob is the same as that of an emitting end Alice, the quantum light pulse modulated by the sagnac ring of the receiving end Bob is subjected to base selection by a polarization controller PC3, then two groups of bases orthogonal in polarization direction are separated by a polarization beam splitter PBS3, and then the detection and counting are carried out by an electro-optic violet detector.
As a further improved technical scheme of the invention, in a double-detector mode, the single-photon detectors are two groups of single-photon detector detection SPDs 1 and single-photon detector SPDs 2.
As a further improved technical scheme of the invention, in a single detector mode, the single-photon detector is a single-photon detector SPD3; one group of bases is connected to a 50 beam splitter BS through a Delay3, the other group of bases is directly connected to the 50 beam splitter BS, and the two groups are combined by the beam splitter BS to a single-photon detector SPD3 for detection and counting.
As a further improved technical scheme of the invention, the Delay value of the Delay3 is D, and D = T/2,T is the system cycle.
As a further improved technical scheme of the invention, the set light intensity is the light intensity of single photon level.
As a further improved technical scheme of the invention, the light pulse of the horizontal polarized light which propagates clockwise is
By adjusting the phase modulator to
Passes through the polarization-maintaining fiber and then returns to the polarization beam splitter PBS1 to become
The quantum state of the light pulse when the counterclockwise-propagating vertically polarized light returns to the polarization beam splitter PBS1 is
As a further improved technical scheme of the invention, a matrix of the optical pulse after passing through the sagnac loop at the Bob end is expressed as follows:
the common phase factor is omitted, and each polarization state can be generated by adjusting the phase difference of the two ends. When the horizontally polarized light and the vertically polarized light are subjected to the optical attenuator VOAWhen the attenuated light is transmitted to a Bob end through an optical fiber channel, a common phase factor is added to both the horizontal polarized light and the vertical polarized light
The light pulses of the horizontally polarized light and the vertically polarized light at this time are represented in a matrix as follows:
the encoding principle of the present invention is that phase modulation polarization state realizes polarization encoding quantum key distribution, and the schemes of the principle have been proposed and proved to be available, but in those schemes, the optical pulse needs to be wound round in both communication sides and returned to the transmitting end, which makes the sagnac loop of phase encoding interferometry limited in realizing long-distance communication. The scheme utilizes a ring type single polarization phase modulation method, namely, the two parties encode by adjusting the phase, the Bob end performs polarization measurement, and the polarization state is transmitted in a channel. The invention has simple structure, low cost, better electrical regulation and polarization control than mechanical control, good system stability, high-speed operation and realization of micro-sized packaging by integrated optical technology in the future; when the receiving end Bob adopts the time-sharing multiplexing technology, one detector is used, and theoretically safe detection is achieved through a corresponding algorithm, so that the purpose of saving the system cost is achieved. As shown in fig. 1, one light beam enters the polarization beam splitter PBS1 and becomes two light beams orthogonal to each other, and then propagates in two directions along the same path, respectively, and after being phase-modulated by the phase modulator PMA, each polarization state of the light can be formed at the exit end of the polarization beam splitter PBS 1. The receiving end Bob can realize active base selection measurement by adjusting the phase, and overcomes the attack to the imperfect BS under the passive base selection. In a word, the invention has the advantages of good stability, simple structure and low cost.
Drawings
Fig. 1 is a schematic view of the structural principle of the present invention.
Fig. 2 is a schematic structural diagram of embodiment 2.
FIG. 3 is a phase difference to polarization state mapping table.
Fig. 4 is a table of the key generation matrix of fig. 3.
Detailed Description
Example 1
Referring to fig. 1, a basic sagnac loop based phase modulated polarization encoded QKD system; the system comprises a transmitting end Alice and a receiving end Bob; the transmitting end Alice and the receiving end Bob are connected through an optical fiber channel; the method is characterized in that: the transmitting end Alice comprises a Laser _ Q, a Laser _ S, a polarization controller PC1, an optical circulator Cir, an optical attenuator VOA, a wavelength division multiplexer WDM and a transmitting end sagnac ring; the transmitting end sagnac ring comprises a polarization beam splitter PBS1, a phase modulator PMA, an optical rotator rotor 1 and a Delay1; polarization maintaining optical fibers are sequentially adopted among the polarization beam splitter PBS1, the phase modulator PMA, the optical rotator1 and the delayer 1 to be connected in series, and the delayer 1 and the polarization beam splitter PBS1 are also connected by the polarization maintaining optical fibers; the phase modulator PMA is used for adjusting single polarization; the Laser _ Q and the Laser _ S are used for generating pulsed light, and the pulsed light generated by the Laser _ Q is used as a quantum signal for system coding to generate a secret key; pulsed light generated by the Laser _ S is used as synchronous light and is used for synchronizing signals at two ends of the system; the polarization controller PC1 is used for converting the quantum optical signal into 45-degree linearly polarized light and transmitting the linearly polarized light to the polarization beam splitter PBS1; the polarization beam splitter PBS1 is used for splitting 45-degree linearly polarized light into horizontal polarized light and vertical polarized light, and the horizontal polarized light and the vertical polarized light are respectively transmitted in polarization-maintaining optical fibers along clockwise and counterclockwise directions; the horizontal polarized light sequentially passes through a phase modulator PMA, a delayer 1 and a rotator1 to reach a polarization beam splitter PBS1; the vertically polarized light sequentially passes through a rotator1, a delayer 1 and a phase modulator PMA to reach a polarization beam splitter PBS1; the optical rotator1 is used for rotating the horizontal polarized light propagating clockwise by 90 degrees into vertical polarized light and rotating the polarization of the vertical polarized light propagating counterclockwise by 90 degrees into horizontal polarized light; the delayer 1 is used for delaying the waiting time, wherein the waiting time is the waiting time required by the polarized light which is required to be transmitted clockwise and anticlockwise when the phase is modulated, and the polarized light only modulates the phase in the clockwise or anticlockwise direction, and the waiting time is required in the other direction; the phase modulator PMA is used to modulate the phase of polarized light in a clockwise or counterclockwise direction; the horizontal polarized light and the vertical polarized light are converged by PBS1, then are emitted to an optical attenuator VOA through an optical circulator Cir and are attenuated to set light intensity by the optical attenuator VOA, then are multiplexed and combined to a common channel with light emitted by a Laser _ S through a wavelength division multiplexer WDM, and then are transmitted to a receiving end Bob through an optical fiber channel;
the receiving end Bob comprises a strong light Detector, a wavelength division multiplexer DWDM, a single photon Detector SPD, a polarization controller PC2, a polarization controller PC3, an optical circulator Cir, a polarization beam splitter PBS3 and a receiving end sagnac ring; the receiving end sagnac loop comprises a polarization beam splitter PBS2, a phase modulator PMB, an optical rotator rotor 2 and a Delay2; after the optical pulse reaches a receiving end Bob, the optical pulse is demultiplexed by a wavelength division multiplexer DWDM, namely, split light is obtained, synchronous light and quantum light are respectively transmitted along different paths, and the synchronous light is detected by a strong light Detector to realize photoelectric conversion for system synchronization; the quantum light pulse is rectified by a polarization controller PC2 and then enters a sagnac ring of a receiving end Bob through a circulator Cir, the working mode of each optical device in the sagnac ring of the receiving end Bob is the same as that of an emitting end Alice, the quantum light pulse modulated by the sagnac ring of the receiving end Bob is subjected to base selection by a polarization controller PC3, then two groups of bases orthogonal in polarization direction are separated by a polarization beam splitter PBS3, and then the detection and counting are carried out by an electro-optic violet detector.
When in a double-detector mode, the single-photon detectors are two groups of single-photon detectors SPD1 and SPD2 on the basis of two groups; the single-photon detector SPD1 and the single-photon detector SPD2 are used for detecting and counting. The Delay value of the Delay3 is D, and D = T/2,T is the system cycle. The set light intensity is the light intensity of a single photon level. The light pulse of the horizontally polarized light propagating clockwise is
By adjusting the phase modulator to
Passes through the polarization-maintaining fiber and then returns to the polarization beam splitter PBS1 to become
The quantum state of the light pulse when the counterclockwise-propagating vertically polarized light returns to the polarization beam splitter PBS1 is
When the horizontally polarized light and the vertically polarized light reach the Bob end after being attenuated by the optical attenuator VOA and transmitted through the optical fiber channel, a common phase factor is added to the horizontally polarized light and the vertically polarized light
The light pulses of the horizontally polarized light and the vertically polarized light at this time are represented in a matrix as follows:
as shown in fig. 1, after the Laser1 generates pulsed light, the pulsed light is made into 45 ° linearly polarized light by the action of the polarization controller PC1 and is incident into the polarization beam splitter PBS1, and at this time, the polarized light is split into horizontal polarized light and vertical polarized light by the polarization beam splitter PBS1, and the two beams of light propagate in the polarization maintaining fiber in the clockwise direction and the counterclockwise direction, respectively. The transmitting end Alice adjusts the clockwise propagating optical pulse by adjusting the single-polarization phase modulator PMA. For a counterclockwise propagating optical pulse, the optical pulse first passes through an optical rotator1 to rotate its polarization by 90 °, and then reaches the phase modulator PMA after a certain Delay through a Delay1, where the voltage of the phase modulator PMA has already been removed. If it is used
Indicating a clockwise propagating optical pulse, becomes by adjusting the phase modulator PMA
Passes through the polarization-maintaining fiber and then returns to the polarization beam splitter PBS1 to become
Accordingly, the quantum state of the counterclockwise propagating optical pulse eventually becomes
The two light pulses are converged at a polarization beam splitter PBS1, are firstly attenuated to certain light intensity by an optical attenuator VOA1 through an optical circulator Cir1, and then are transmitted to a receiving end Bob through an optical fiber channel, and at the moment, a common phase factor is added to the two light pulses
The light pulse is now represented in a matrix as:
the receiving end sagnac loop is completely the same as the transmitting end sagnac loop, and the receiving end Bob realizes coding by adjusting the phase modulator PMB. The quantum state of the light pulse coming out of the polarizing beam splitter PBS2 now changes to
By omitting the common phase factor, we know that individual polarization states can be generated by adjusting the phase difference.
The invention has another advantage that Bob end can realize active base selection measurement by adjusting the phase, thus overcoming the attack to imperfect BS under passive base selection. Phase difference between two ends
The relationship to the modulated polarization state is shown in fig. 3: we specify that the phase 0, pi represents the "0" group,
representing the "1" basis, alice randomly modulates the phase: 0,
π，
bob also randomly modulates the phase: 0,
π，
the Bob end corresponds to the gating measurement. If Alice modulates the phase on the base of '0', bob modulates the phase on the base of 0, pi, namely the base of '0', the phase is considered to be selected as the base, and the code can be formed by detection if Bob selects the base
That is, the phase at the "1" base is considered to have no selected pairing base, and in this case, the pairing base is discarded when both the communication parties pair. The law of formation of the traffic key quantity is shown in FIG. 4, in which
Indicating that the detector can detect with 50% probability, 1 (SPD 1) indicating that the SPD1 detector detects 100%, 1 (SPD 2) indicating that the SPD2 detector detects 100% of SPD1, and two single-photon detectors at the receiving ends of the SPD2.
Example 2
As shown in fig. 2, a receiver Bob of the QKD system based on phase modulation polarization coding of a sagnac loop time-division multiplexes a detector, i.e., a single-probe sagnac loop system, i.e., in a single detector mode, and the single-photon detector is a single-photon detector SPD3; one group of bases is connected to a 50 beam splitter BS through a Delay3, the other group of bases is directly connected to the 50 beam splitter BS, and the two groups are combined by the beam splitter BS to a single-photon detector SPD3 for detection and counting. At this time, the equal probability of the two groups of bases needs to be considered, so that the theoretical absolute safety is realized. The rest of the process is the same as in example 1 and will not be described in detail.
Claims (5)
1. A sagnac loop based phase modulated polarization encoded QKD system; the system comprises a transmitting end Alice and a receiving end Bob; the transmitting end Alice and the receiving end Bob are connected through an optical fiber channel; the method is characterized in that: the transmitting end Alice comprises a Laser _ Q, a Laser _ S, a polarization controller PC1, an optical circulator Cir, an optical attenuator VOA, a wavelength division multiplexer WDM and a transmitting end sagnac ring; the transmitting end sagnac ring comprises a polarization beam splitter PBS1, a phase modulator PMA, an optical rotator rotor 1 and a Delay1; polarization maintaining optical fibers are sequentially adopted among the polarization beam splitter PBS1, the phase modulator PMA, the optical rotator1 and the delayer 1 to be connected in series, and the delayer 1 and the polarization beam splitter PBS1 are also connected by the polarization maintaining optical fibers; the phase modulator PMA is used for adjusting single polarization; the Laser _ Q and the Laser _ S are used for generating pulsed light, and the pulsed light generated by the Laser _ Q is used as a quantum signal for system coding to generate a secret key; pulsed light generated by the Laser _ S is used as synchronous light and is used for synchronizing signals at two ends of the system; the polarization controller PC1 is used for converting the quantum optical signal into 45-degree linearly polarized light and emitting the linearly polarized light into the polarization beam splitter PBS1; the polarization beam splitter PBS1 is used for splitting 45-degree linearly polarized light into horizontal polarized light and vertical polarized light, and the horizontal polarized light and the vertical polarized light are respectively transmitted in the polarization maintaining optical fiber along clockwise direction and anticlockwise direction; the horizontal polarized light sequentially passes through a phase modulator PMA, a delayer 1 and a rotator1 to reach a polarization beam splitter PBS1; the vertically polarized light sequentially passes through a rotator1, a Delay1 and a phase modulator PMA to reach a polarization beam splitter PBS1; the optical rotator1 is used for rotating the horizontal polarized light propagating clockwise by 90 degrees into vertical polarized light and rotating the polarization of the vertical polarized light propagating counterclockwise by 90 degrees into horizontal polarized light; the delayer 1 is used for delaying the waiting time, wherein the waiting time is the waiting time required by the polarized light which is required to be transmitted clockwise and anticlockwise when the phase is modulated, and the polarized light only modulates the phase in the clockwise or anticlockwise direction, and the waiting time is required in the other direction; the phase modulator PMA is used for modulating the phase of polarized light in the clockwise direction or the anticlockwise direction, the horizontally polarized light and the vertically polarized light are converged by the PBS1, then are emitted to the optical attenuator VOA through the optical circulator Cir and are attenuated to set light intensity by the optical attenuator VOA, then are multiplexed and combined to a public channel through the wavelength division multiplexer WDM with the light emitted by the Laser _ S, and then are transmitted to the receiving end Bob through the optical fiber channel;
the receiving end Bob comprises a strong light Detector, a wavelength division multiplexer DWDM, a single photon Detector SPD, a polarization controller PC2, a polarization controller PC3, an optical circulator Cir, a polarization beam splitter PBS3 and a receiving end sagnac ring; the receiving end sagnac loop comprises a polarization beam splitter PBS2, a phase modulator PMB, an optical rotator rotor 2 and a Delay2;
after the optical pulse reaches a receiving end Bob, the optical pulse is demultiplexed by a wavelength division multiplexer DWDM, namely, split light is obtained, synchronous light and quantum light are respectively transmitted along different paths, and the synchronous light is detected by a strong light Detector to realize photoelectric conversion for system synchronization; the quantum light pulse is rectified by a polarization controller PC2 and then enters a sagnac ring of a receiving end Bob through a circulator Cir, the working modes of optical devices in the sagnac ring of the receiving end Bob are the same as that of an emitting end Alice, the quantum light pulse modulated by the sagnac ring of the receiving end Bob is subjected to base selection by a polarization controller PC3, then two groups of bases orthogonal in polarization direction are separated by a polarization beam splitter PBS3, and then the quantum light pulse is detected and counted by a single-photon detector.
2. The sagnac loop-based phase modulated polarization encoded QKD system of claim 1, wherein: in the double-detector mode, the single-photon detectors are two groups of single-photon detectors SPD1 and SPD2 on the basis of one group.
3. The sagnac loop-based phase modulated polarization encoded QKD system of claim 1, wherein: when in the single detector mode, the single-photon detector is a single-photon detector SPD3; one group of bases is connected to a 50 beam splitter BS through a Delay3, the other group of bases is directly connected to the 50 beam splitter BS, and the two paths are combined by the beam splitter BS to a single-photon detector SPD3 for detection and counting.
4. The sagnac loop-based phase modulated polarization encoded QKD system of claim 3, wherein: the Delay value of the Delay3 is D, and D = T/2,T is the system cycle.
5. The sagnac loop-based phase modulated polarization encoded QKD system of claim 3, wherein: the set light intensity is the light intensity of a single photon level.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610362025.5A CN105897413B (en) | 2016-05-26 | 2016-05-26 | Sagnac loop-based phase modulation polarization encoded QKD system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610362025.5A CN105897413B (en) | 2016-05-26 | 2016-05-26 | Sagnac loop-based phase modulation polarization encoded QKD system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN105897413A CN105897413A (en) | 2016-08-24 |
| CN105897413B true CN105897413B (en) | 2022-10-18 |
Family
ID=56717959
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610362025.5A Active CN105897413B (en) | 2016-05-26 | 2016-05-26 | Sagnac loop-based phase modulation polarization encoded QKD system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN105897413B (en) |
Families Citing this family (31)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107872314B (en) | 2016-09-27 | 2020-06-26 | 华为技术有限公司 | Encoding device, light reflector and quantum key distribution equipment and system based on light reflector |
| CN108075885B (en) * | 2016-11-15 | 2021-02-12 | 上海朗研光电科技有限公司 | Phase modulation polarization coding high-speed quantum key distribution system |
| CN107070561B (en) * | 2016-12-19 | 2022-10-14 | 北京大学 | Channel multiplexing device based on double-circuit plug-and-play QKD system |
| CN106850213B (en) * | 2017-03-08 | 2023-08-25 | 浙江九州量子信息技术股份有限公司 | Quantum key distribution system and method |
| CN106789048B (en) * | 2017-03-08 | 2023-08-18 | 浙江九州量子信息技术股份有限公司 | Quantum key distribution system and method based on two-way single photon detection |
| CN106656494B (en) * | 2017-03-08 | 2023-08-18 | 浙江九州量子信息技术股份有限公司 | Quantum key distribution system and method based on continuous photointerruption |
| CN108737082B (en) | 2017-04-24 | 2020-11-17 | 华为技术有限公司 | Signal receiving device and receiving method |
| CN107135071B (en) * | 2017-06-01 | 2023-08-18 | 浙江九州量子信息技术股份有限公司 | Quantum key distribution system and method based on time division multiplexing |
| CN107276758A (en) * | 2017-07-28 | 2017-10-20 | 浙江九州量子信息技术股份有限公司 | A kind of quantum key dispatching system and method based on Waveguide interference ring |
| CN107276757A (en) * | 2017-07-28 | 2017-10-20 | 浙江九州量子信息技术股份有限公司 | A kind of quantum key dispatching system controlled based on photoswitch and method |
| CN107241189B (en) * | 2017-07-28 | 2023-08-25 | 浙江九州量子信息技术股份有限公司 | Quantum key distribution system and method based on vacuum state non-triggering |
| CN107437966B (en) * | 2017-08-08 | 2019-08-09 | 安徽问天量子科技股份有限公司 | Both ends polarization state initial method based on phase-modulated polarized state coding QKD system |
| CN113810116B (en) * | 2017-09-01 | 2023-02-03 | 华为技术有限公司 | Optical signal transmission system and optical signal transmission method |
| CN109560876B (en) * | 2017-09-26 | 2020-05-15 | 中国科学技术大学 | Time phase-polarization encoding device, decoding device, and quantum communication system |
| CN109962772B (en) * | 2017-12-14 | 2024-04-16 | 科大国盾量子技术股份有限公司 | Silicon-based integrated quantum key distribution chip based on coupling polarization beam splitter |
| CN107979463B (en) * | 2018-01-22 | 2020-06-26 | 中国科学技术大学 | Phase encoder-decoder and quantum key distribution system |
| CN108667527B (en) * | 2018-04-11 | 2019-11-22 | 中国人民解放军战略支援部队信息工程大学 | A kind of detection device and method of single-photon detector detection efficient mismatch |
| CN108923919B (en) * | 2018-07-18 | 2020-12-08 | 安徽问天量子科技股份有限公司 | Control method and control system for base selection device of base-biased quantum cryptography system |
| CN109327266A (en) * | 2018-08-24 | 2019-02-12 | 中国电子科技集团公司第三十研究所 | A kind of High Extinction Ratio light pulse production method suitable for CVQKD system |
| CN109257104A (en) * | 2018-08-24 | 2019-01-22 | 中国电子科技集团公司第三十研究所 | A kind of light amplitude modulator approach suitable for CVQKD system |
| CN110620654B (en) * | 2018-11-02 | 2022-09-16 | 科大国盾量子技术股份有限公司 | Random polarization state transmitting device, receiving device and quantum communication system |
| CN109946941A (en) * | 2019-04-17 | 2019-06-28 | 上海师范大学 | The optical image encryption system and method for interference based on Sagnac effect |
| CN110380853A (en) * | 2019-07-24 | 2019-10-25 | 赵义博 | A kind of polarization encoder quantum key distribution system |
| CN112104452B (en) * | 2019-09-04 | 2022-05-03 | 科大国盾量子技术股份有限公司 | Light splitting assembly, polarization decoding device for quantum key distribution and receiving end |
| CN111464302A (en) * | 2020-05-10 | 2020-07-28 | 神盾迅波(北京)量子科技发展有限公司 | Quantum key distribution system based on B92 protocol |
| CN111526019A (en) * | 2020-05-26 | 2020-08-11 | 中国科学技术大学 | Two-stage polarization encoding device, encoding method and quantum key distribution light source |
| CN113504030B (en) * | 2021-07-20 | 2024-03-12 | 安徽问天量子科技股份有限公司 | Phase randomization testing device and method for high-speed pulse laser |
| CN113810191B (en) * | 2021-10-29 | 2023-10-27 | 武汉船舶通信研究所（中国船舶重工集团公司第七二二研究所） | Quantum key distribution system, encoder, decoder and method based on circularly polarized light |
| CN114531226B (en) * | 2021-12-28 | 2023-06-30 | 华南师范大学 | Multi-user sagnac ring QKD system and method based on time division-mode division multiplexing |
| CN114553402B (en) * | 2021-12-31 | 2023-06-30 | 华南师范大学 | QKD system and method based on sagnac loop and irrelevant to reference system irrelevant measurement equipment |
| CN116723054B (en) * | 2023-08-08 | 2023-10-27 | 合肥量芯科技有限公司 | Method for resisting detection efficiency mismatch loopholes introduced in calibration process |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103969841A (en) * | 2013-01-30 | 2014-08-06 | 中国科学院空间科学与应用研究中心 | All optical fiber high-speed polarization controlling system and method |
| CN205912068U (en) * | 2016-05-26 | 2017-01-25 | 安徽问天量子科技股份有限公司 | QKD system of phase modulation polarization code based on sagnac ring |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8433070B2 (en) * | 2010-05-17 | 2013-04-30 | Raytheon Bbn Technologies Corp. | Systems and methods for stabilization of interferometers for quantum key distribution |
-
2016
- 2016-05-26 CN CN201610362025.5A patent/CN105897413B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103969841A (en) * | 2013-01-30 | 2014-08-06 | 中国科学院空间科学与应用研究中心 | All optical fiber high-speed polarization controlling system and method |
| CN205912068U (en) * | 2016-05-26 | 2017-01-25 | 安徽问天量子科技股份有限公司 | QKD system of phase modulation polarization code based on sagnac ring |
Non-Patent Citations (2)
| Title |
|---|
| 全光纤量子通信系统中的高速偏振控制方案;李申等;《物理学报》;20130423(第08期);全文 * |
| 基于双偏振分束器的量子密钥分发系统;马海强等;《物理学报》;20051112(第11期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN105897413A (en) | 2016-08-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105897413B (en) | Sagnac loop-based phase modulation polarization encoded QKD system | |
| Vagniluca et al. | Efficient time-bin encoding for practical high-dimensional quantum key distribution | |
| Zhang et al. | Continuous-variable QKD over 50 km commercial fiber | |
| US9401766B2 (en) | Quantum communication network | |
| CN106161011B (en) | Plug-and-play quantum key distribution system and method based on time-phase coding, sending end and receiving end | |
| CN103414553B (en) | The quantum key distribution system compensated based on time slot interleaving active polarization and method | |
| CA2254767C (en) | Method and apparatus for polarisation-insensitive quantum cryptography | |
| EP2081317A2 (en) | Quantum key distribution system and method of performing quantum key distribution | |
| WO2018059338A1 (en) | Encoding apparatus, and quantum key distribution device and system based on same | |
| CN110620652A (en) | Quantum key distribution system and communication method thereof | |
| CN206506541U (en) | A kind of high speed quantum key distribution system of phase-modulated polarized coding | |
| CN106161010A (en) | The high one-tenth point-to-point QKD system of code check and transmitting terminal, receiving terminal and QKD method | |
| WO2006074151A2 (en) | Secure use of a single single-photon detector in a qkd system | |
| WO2007033560A1 (en) | Method and system for quantum key distribution over multi-user wdm network with wavelength routing | |
| CN109039475A (en) | Continuous variable quantum key delivering method and system based on free space | |
| CN210112021U (en) | Polarization encoding quantum key distribution system | |
| Avesani et al. | Deployment-ready quantum key distribution over a classical network infrastructure in Padua | |
| Li et al. | Free-space and fiber-integrated measurement-device-independent quantum key distribution under high background noise | |
| CN112039671A (en) | Efficient quantum key distribution system and method | |
| CN114629563A (en) | Polarization multiplexing quantum key distribution device and full-time full-pass quantum key distribution network | |
| CN205912068U (en) | QKD system of phase modulation polarization code based on sagnac ring | |
| Scalcon et al. | Cross‐Encoded Quantum Key Distribution Exploiting Time‐Bin and Polarization States with Qubit‐Based Synchronization | |
| CN104065476A (en) | Multifunctional quantum secret communication node structure based on time division-wavelength division multiplexing | |
| CN210629516U (en) | Quantum key distribution system for polarization and phase composite coding | |
| CN110351070B (en) | Quantum key distribution system and method based on Y waveguide |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |