CN109150522B - Quantum key distribution time bit-phase decoding method and device and corresponding system - Google Patents
Quantum key distribution time bit-phase decoding method and device and corresponding system Download PDFInfo
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- 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
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/70—Photonic quantum communication
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/50—Transmitters
- H04B10/516—Details of coding or modulation
- H04B10/524—Pulse modulation
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- H—ELECTRICITY
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- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
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- H04B10/516—Details of coding or modulation
- H04B10/532—Polarisation modulation
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- H04B10/516—Details of coding or modulation
- H04B10/548—Phase or frequency modulation
- H04B10/556—Digital modulation, e.g. differential phase shift keying [DPSK] or frequency shift keying [FSK]
- H04B10/5561—Digital phase modulation
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Abstract
The invention provides a quantum key distribution time bit-phase decoding method and device based on polarization orthogonal rotation reflection and a corresponding system. The method comprises the following steps: splitting an input optical pulse into first and second optical pulses; according to the quantum key distribution protocol, the first path of optical pulse is subjected to phase decoding and the second path of optical pulse is subjected to time bit decoding. The phase decoding of the first path of light pulse comprises the steps of splitting the first path of light pulse into two sub-light pulses through a beam splitter, respectively transmitting the two sub-light pulses along two sub-light paths, relatively delaying the two sub-light pulses, respectively reflecting the two sub-light pulses back to the beam splitter through two reflecting devices for beam combination output, wherein when each sub-light pulse is reflected by the corresponding reflecting device, two orthogonal polarization states of the sub-light pulse are subjected to polarization orthogonal rotation reflection, and the first path of light pulse or one of the two sub-light pulses obtained by splitting the first path of light pulse is subjected to phase modulation. The invention provides a time bit-phase coding quantum key distribution decoding scheme which is easy to realize and apply and is resistant to polarization induced fading.
Description
Technical Field
The present invention relates to the field of optical transmission secret communication technologies, and in particular, to a method and an apparatus for decoding a quantum key distribution time bit-phase based on polarization orthogonal rotation reflection, and a quantum key distribution system including the apparatus.
Background
Quantum secret communication technology is the leading-edge hotspot field combining quantum physics and information science. Based on the quantum key distribution technology and the one-time secret code principle, the quantum secret communication can realize the safe transmission of information in a public channel. The quantum key distribution is based on the physical principles of quantum mechanics Hessenberg uncertainty relation, quantum unclonable theorem and the like, can realize safe sharing of keys among users, can detect potential eavesdropping behaviors, and can be applied to the fields of national defense, government affairs, finance, electric power and other high-safety information transmission requirements.
The time bit-phase encoded quantum key distribution employs a set of time bases encoded using time patterns of two different time positions and a set of phase bases encoded using two phase differences of the front and rear light pulses. The ground quantum key distribution is mainly based on fiber channel transmission, but the optical fiber manufacturing has non-ideal conditions of non-circular symmetry in section, non-uniform distribution of refractive index of fiber cores along radial directions and the like, and the optical fiber is influenced by temperature, strain, bending and the like in an actual environment, so that random birefringence effect can be generated. The polarization state of the light pulse is randomly changed when the light pulse reaches a receiving end after the light pulse is transmitted by a long-distance optical fiber under the influence of the random birefringence of the optical fiber. The time base decoding in the time bit-phase coding is not influenced by the change of the polarization state, however, when the phase base is in interference decoding, the problem of polarization induced fading exists due to the influence of double refraction of a transmission optical fiber and a decoding interferometer optical fiber, so that the decoding interference is unstable, the error rate is increased, correction equipment is required to be added, the complexity and the cost of a system are increased, and stable application is difficult to realize under the condition of strong interference such as an overhead optical cable, a road bridge optical cable and the like. For a quantum key distribution time bit-phase encoding scheme, how to stably and efficiently perform phase interference decoding is a hotspot and a difficulty in quantum secret communication application based on the existing optical cable infrastructure.
Disclosure of Invention
The invention mainly aims to provide a quantum key distribution time bit-phase decoding method and device based on polarization orthogonal rotation reflection, which are used for solving the problem of unstable phase decoding interference caused by polarization induced fading in phase base decoding in time bit-phase coding quantum key distribution application.
The invention provides at least the following technical scheme:
1. a quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection, the method comprising:
splitting an incident input light pulse with any polarization state into a first light pulse and a second light pulse; and
according to the quantum key distribution protocol, the first path of light pulse is subjected to phase decoding and the second path of light pulse is subjected to time bit decoding,
wherein phase decoding the first optical pulse includes:
splitting the first path of optical pulse into two sub-optical pulses through a beam splitter; and
transmitting the two sub-optical pulses along two sub-optical paths respectively, and reflecting the two sub-optical pulses back to the beam splitter via two reflecting devices respectively after relative delay to be output by the beam splitter, wherein for each of the two sub-optical pulses:
The two orthogonal polarization states of the sub-light pulse are polarization-orthogonally rotated for reflection when the sub-light pulse is reflected by the respective one of the two reflecting means, such that after reflection by the respective reflecting means, each orthogonal polarization state of the sub-light pulse is transformed into a polarization state orthogonal thereto,
the input optical pulse before splitting is subjected to phase modulation according to a quantum key distribution protocol, or the first optical pulse is subjected to phase modulation according to the quantum key distribution protocol before splitting, or at least one of the two sub-optical pulses transmitted on the two sub-optical paths is subjected to phase modulation according to the quantum key distribution protocol in the process of splitting the first optical pulse to combining the beams.
2. The quantum key distribution time bit-phase decoding method based on polarization orthogonal rotation reflection according to claim 1, wherein the two reflection devices are circular polarization orthogonal rotation reflection devices.
3. The quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection according to claim 2, wherein the two reflection means each include a mirror.
4. The quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection according to any one of aspects 1 to 3, wherein the beam splitter is a circular polarization maintaining beam splitter.
5. The quantum key distribution time bit-phase decoding method based on polarization orthogonal rotation reflection according to claim 1, wherein the two reflection devices are linear polarization orthogonal rotation reflection devices.
6. The quantum key distribution time bit-phase decoding method based on polarization orthogonal rotation reflection according to claim 5, wherein the two reflection devices each include a mirror and a quarter wave plate, the mirror is integrally formed with the quarter wave plate at a rear end of the quarter wave plate, and an included angle between a polarization direction of one of two orthogonal polarization states of each of the two sub-optical pulses and a fast axis or a slow axis of the quarter wave plate is 45 degrees.
7. The quantum key distribution time bit-phase decoding method based on polarization orthogonal rotation reflection according to claim 1 or 5 or 6, wherein the beam splitter is a line polarization maintaining beam splitter.
8. The quantum key distribution time bit-phase decoding method based on polarization orthogonal rotation reflection according to claim 1, wherein the two reflection devices are elliptical polarization orthogonal rotation reflection devices.
9. The quantum key distribution time bit-phase decoding method based on polarization orthogonal rotation reflection according to claim 1 or 8, wherein the beam splitter is an elliptical polarization maintaining beam splitter.
10. The quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection according to any one of schemes 1 to 9, wherein for each of the two sub-optical pulses:
the two orthogonal polarization states of the sub-optical pulse are kept unchanged during the beam splitting by the beam splitter to the reflection of the corresponding reflection means and unchanged during the beam combining by the corresponding reflection means.
11. The quantum key distribution time bit-phase decoding method based on polarization orthogonal rotation reflection according to claim 1, wherein the two reflection devices each comprise a 90-degree rotating faraday mirror, and the beam splitter is a polarization-maintaining beam splitter or a non-polarization-maintaining beam splitter.
12. The quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection according to claim 1, wherein time bit decoding the second path of light pulse comprises:
directly outputting the second path of light pulse for detection; or alternatively
And splitting the second path of light pulse and outputting the split light pulse for detection.
13. A quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection, the decoding device comprising:
the front beam splitter is used for splitting one path of input light pulse with any incident polarization state into a first path of light pulse and a second path of light pulse; the method comprises the steps of,
a phase decoder optically coupled to the pre-splitter for phase decoding the first optical pulse,
the phase decoder comprises a first beam splitter, two reflecting devices and two sub-optical paths optically coupled with the first beam splitter and the two reflecting devices, wherein
The first beam splitter is used for splitting the first path of light pulse into two sub-light pulses;
the two sub-optical paths are used for respectively transmitting the two sub-optical pulses and realizing the relative delay of the two sub-optical pulses;
the two reflecting devices are used for respectively reflecting the two sub-optical pulses transmitted by the two sub-optical paths from the first beam splitter back to the first beam splitter to be output by the first beam splitter;
Wherein the two reflecting means are configured such that, for each of the two sub-light pulses: the two orthogonal polarization states of the sub-light pulse are polarization-orthogonally rotated for reflection when the sub-light pulse is reflected by the respective one of the two reflecting means, such that after reflection by the respective reflecting means, each orthogonal polarization state of the sub-light pulse is transformed into a polarization state orthogonal thereto,
wherein the decoding device is provided with a phase modulator positioned at the front end of the front beam splitter or at the front end of the first beam splitter or on any one of the two sub-optical paths, the phase modulator is used for carrying out phase modulation on the light pulse passing through the phase modulator according to a quantum key distribution protocol,
wherein the pre-splitter outputs the second optical pulse for temporal bit decoding.
14. The quantum key distribution time bit-phase decoding apparatus based on polarization orthogonal rotation reflection according to claim 13, wherein the two reflection apparatuses are circular polarization orthogonal rotation reflection apparatuses.
15. The quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection according to claim 14, wherein the two reflection apparatuses each include a mirror.
16. The quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection according to any one of claims 13 to 15, wherein the first beam splitter is a circular polarization maintaining beam splitter.
17. The quantum key distribution time bit-phase decoding apparatus based on polarization orthogonal rotation reflection according to claim 13, wherein the two reflection apparatuses are linear polarization orthogonal rotation reflection apparatuses.
18. The quantum key distribution time bit-phase decoding apparatus based on polarization orthogonal rotation reflection according to claim 17, wherein the two reflecting means each include a reflecting mirror and a quarter wave plate, the reflecting mirror being integrally formed with the quarter wave plate at a rear end thereof, wherein the quarter wave plate is configured such that a polarization direction of one of two orthogonal polarization states of each of the two sub-optical pulses is 45 degrees from a fast axis or a slow axis of the quarter wave plate.
19. The quantum key distribution time bit-phase decoding apparatus based on polarization orthogonal rotation reflection according to claim 13 or 17 or 18, wherein the first beam splitter is a line polarization maintaining beam splitter.
20. The quantum key distribution time bit-phase decoding apparatus based on polarization orthogonal rotation reflection according to claim 13, wherein the two reflection apparatuses are elliptical polarization orthogonal rotation reflection apparatuses.
21. The quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection according to claim 13 or 20, wherein the first beam splitter is an elliptical polarization maintaining beam splitter.
22. The quantum key distribution time bit-phase decoding apparatus based on polarization orthogonal rotation reflection according to any one of claims 13 to 21, wherein the two sub-optical paths are polarization maintaining optical paths, and the optical devices on the two sub-optical paths are polarization maintaining optical devices and/or non-birefringent optical devices.
23. The quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection of claim 13, wherein the two reflection devices each comprise a 90 degree rotating faraday mirror, and the first beam splitter is a polarization maintaining beam splitter or a non-polarization maintaining beam splitter.
24. The quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection of claim 13, wherein the decoding apparatus further comprises a second beam splitter optically coupled to the front beam splitter for receiving the second optical pulse and splitting the second optical pulse for output for time bit decoding.
25. A quantum key distribution system comprising:
the quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection according to any one of schemes 13 to 24, which is provided at a receiving end of the quantum key distribution system for time bit-phase decoding; and/or
The quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection according to any one of claims 13 to 24, which is provided at a transmitting end of the quantum key distribution system for time bit-phase encoding.
The invention achieves unexpected beneficial effects through creative configuration. Aiming at the time bit-phase coding quantum key distribution application, the invention utilizes the polarization orthogonal rotation reflection to control the phase difference of two orthogonal polarization states of light pulses in phase-based decoding to be equal in transmission of two arms of a decoding interference ring, realizes the effective interference output of the two orthogonal polarization states at an output port, thereby realizing the phase-based decoding function of environment interference immunity and realizing the stable time bit-phase coding quantum key distribution solution of environment interference immunity. The present invention provides a time bit-phase encoded quantum key distribution solution that is easy to implement and apply that is resistant to polarization induced fading while avoiding the need for complex deskewing equipment.
Drawings
FIG. 1 is a flow chart of a quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection according to a preferred embodiment of the present invention;
FIG. 2 is a schematic diagram showing the structure of a quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection according to a preferred embodiment of the present invention;
FIG. 3 is a schematic diagram showing the constitution of a quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection according to another preferred embodiment of the present invention;
FIG. 4 is a schematic diagram showing the constitution of a quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection according to another preferred embodiment of the present invention;
fig. 5 is a schematic diagram showing the composition and structure of a quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection according to another preferred embodiment of the present invention.
Detailed Description
Preferred embodiments of the present invention are described in detail below with reference to the attached drawing figures, which form a part of the present application and, together with the embodiments of the present invention, serve to explain the principles of the invention. For the purposes of clarity and simplicity, detailed descriptions of known functions and configurations incorporated herein will be omitted when it may obscure the subject matter of the present invention.
A quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection according to a preferred embodiment of the present invention is shown in fig. 1, and includes the following steps:
step S101: and splitting an incident input light pulse with any polarization state into a first light pulse and a second light pulse.
The input light pulse is in any polarization state, and can be linear polarized, circular polarized or elliptical polarized completely polarized light, or can be partial polarized light or unpolarized light.
Step S102: and according to a quantum key distribution protocol, performing phase decoding on the first path of optical pulse and performing time bit decoding on the second path of optical pulse.
As will be appreciated by those skilled in the art, each light pulse may be seen as consisting of two orthogonal polarization states. Naturally, two sub-optical pulses, which are obtained by splitting an optical pulse, can also be seen as consisting of the same two orthogonal polarization states as the optical pulse.
According to the present invention, phase decoding the first optical pulse may include:
splitting the first path of optical pulse into two sub-optical pulses through a beam splitter; and
transmitting the two sub-optical pulses along two sub-optical paths respectively, and reflecting the two sub-optical pulses back to the beam splitter via two reflecting devices respectively after relative delay to be output by the beam splitter, wherein for each of the two sub-optical pulses:
The two orthogonal polarization states of the sub-light pulse are polarization-orthogonally rotated for reflection when the sub-light pulse is reflected by a respective one of the two reflecting means, such that each orthogonal polarization state of the sub-light pulse is transformed into a polarization state orthogonal thereto upon reflection by the respective reflecting means.
For example, assuming that the two orthogonal polarization states are an x polarization state and a y polarization state, respectively, the x polarization state transmitted to one reflecting device along the optical path is transformed into a polarization state orthogonal thereto, i.e., a y polarization state, after polarization orthogonal rotation reflection at the reflecting device, and the y polarization state transmitted to the reflecting device along the optical path is transformed into a polarization state orthogonal thereto, i.e., an x polarization state, after polarization orthogonal rotation reflection at the reflecting device.
In this way, by utilizing polarization orthogonal rotation reflection at the reflecting device, the phase difference of the x polarization state of each path of light pulse obtained by beam splitting is exactly equal to the phase difference of the y polarization state of the light pulse transmitted by the two sub-optical paths in the beam splitting to beam combining process of the beam splitter.
In the method, two sub-optical pulses are respectively reflected by two reflecting devices for odd times or respectively reflected by two reflecting devices for even times (including zero times, namely direct transmission) and then are output by the beam splitter.
In the method of fig. 1, the phase modulation is performed as follows in the phase decoding of the first optical pulse according to the quantum key distribution protocol: before splitting the first path of light pulse, carrying out phase modulation on the first path of light pulse according to a quantum key distribution protocol; or in the process of beam splitting of the beam splitter to beam combining of the beam splitter, at least one of the two sub-optical pulses transmitted on the two sub-optical paths is subjected to phase modulation according to a quantum key distribution protocol. In the former case, for example, phase modulation of a first optical pulse according to the quantum key distribution protocol may be achieved by phase modulating one of the two input optical pulses adjacent to each other in the optical pulse.
The relative delay and phase modulation are performed as required and specified by the quantum key distribution protocol and are not described in detail herein.
According to one possible configuration, the two reflecting means are circularly polarized orthogonal rotating reflecting means. For example, the two reflecting means each comprise a mirror. In this case, the beam splitter may be a circular polarization maintaining beam splitter. Here, the circularly polarized orthogonal rotation reflecting device is a reflecting device capable of performing polarization orthogonal rotation reflection on incident circularly polarized light, that is, converting the polarization state of the circularly polarized light into a polarization state orthogonal thereto when reflecting the incident circularly polarized light, that is: the incident left-handed circularly polarized light is reflected by the circular polarization orthogonal rotation reflecting device and then is converted into right-handed circularly polarized light orthogonal to the circular polarization orthogonal rotation reflecting device, and the incident right-handed circularly polarized light is reflected by the circular polarization orthogonal rotation reflecting device and then is converted into left-handed circularly polarized light orthogonal to the circular polarization orthogonal rotation reflecting device.
According to another possible configuration, the two reflecting means are linear polarization orthogonal rotating reflecting means. For example, each of the two reflecting devices includes a reflecting mirror and a quarter-wave plate, the reflecting mirror is integrally formed with the quarter-wave plate at the rear end of the quarter-wave plate, wherein an included angle between a polarization direction of each of two orthogonal polarization states of the two sub-optical pulses and a fast axis or a slow axis of the quarter-wave plate is 45 degrees. In this case, the beam splitter may be a line polarization maintaining beam splitter. The reflecting device comprising the reflecting mirror and the quarter wave plate can be called as a quarter wave plate reflecting mirror for short, can be realized by plating the reflecting mirror on the surface of a crystal of the quarter wave plate, and can also be realized by plating the reflecting mirror on the end face of the polarization maintaining optical fiber with the phase difference of 90 degrees in the fast and slow axes. Here, the linear polarization orthogonal rotation reflecting device is a reflecting device capable of performing polarization orthogonal rotation reflection on incident linear polarization state light, that is, converting the polarization state of the linear polarization state light into a polarization state orthogonal thereto when reflecting the incident linear polarization state light, that is: the incident x-ray polarized light is reflected by the linear polarization orthogonal rotation reflecting device and then is converted into y-ray polarized light orthogonal to the incident x-ray polarized light, and the incident y-ray polarized light is reflected by the linear polarization orthogonal rotation reflecting device and then is converted into x-ray polarized light orthogonal to the incident y-ray polarized light.
According to yet another possible configuration, the two reflecting means are elliptical polarization orthogonal rotation reflecting means, and the beam splitter may be an elliptical polarization maintaining beam splitter. In this case, a suitable reflecting means may be selected according to the specific elliptical polarization maintaining beam splitter. Here, the elliptical polarization orthogonal rotation reflecting device is a reflecting device capable of performing polarization orthogonal rotation reflection on incident elliptical polarized light, that is, converting the polarized state of the elliptical polarized light into a polarized state orthogonal thereto when reflecting the incident elliptical polarized light, that is: the incident left-handed elliptical polarized light is reflected by the elliptical polarization orthogonal rotation reflecting device and then is converted into right-handed elliptical polarized light orthogonal to the elliptical polarization orthogonal rotation reflecting device, and the incident right-handed elliptical polarized light is reflected by the elliptical polarization orthogonal rotation reflecting device and then is converted into left-handed elliptical polarized light orthogonal to the elliptical polarization orthogonal rotation reflecting device.
For the above several configurations, advantageously, for each of the two sub-optical pulses obtained by beam splitting of the first optical pulse: the two orthogonal polarization states of the sub-optical pulse are kept unchanged during the beam splitting by the beam splitter to the reflection of the corresponding reflection means and unchanged during the beam combining by the corresponding reflection means. This may be achieved, for example, by configuring the two sub-optical paths as polarization maintaining optical paths and configuring the optical devices on the two sub-optical paths as polarization maintaining optical devices and/or non-birefringent optical devices.
According to yet another possible configuration, the two reflecting means each comprise a 90 degree rotating faraday mirror. In this case, the beam splitter may be a polarization maintaining beam splitter or a non-polarization maintaining beam splitter.
The phase modulating the first path of light pulse according to the quantum key distribution protocol may include: the first path of light pulse is randomly subjected to 0-degree phase modulation or 180-degree phase modulation. Phase modulating at least one of the two sub-optical pulses transmitted on the two sub-optical paths according to a quantum key distribution protocol may comprise: one of the two sub-optical pulses transmitted on the two sub-optical paths is randomly subjected to 0-degree phase modulation or 180-degree phase modulation. Here, randomly performing 0-degree phase modulation or 180-degree phase modulation means randomly performing phase modulation selected from both 0-degree phase modulation and 180-degree phase modulation.
In the method of fig. 1, time bit decoding the second optical pulse includes: directly outputting the second path of light pulse for detection; or the second path of light pulse is output for detection after being split.
A quantum key distribution time bit-phase decoding device based on polarization orthogonal rotation reflection according to a preferred embodiment of the present invention is shown in fig. 2, and includes the following components: front beam splitter 201, beam splitters 202 and 205, phase modulator 206, and two reflecting devices 207 and 208. The two sub-optical paths are interposed between beam splitter 205 and two reflecting means 207 and 208, optically coupled to beam splitter 205 and optically coupled to two reflecting means 207 and 208, respectively. One of the two sub-optical paths is provided with a phase modulator 206. The beam splitter 205, the two reflecting means 207 and 208 and the two sub-optical paths therebetween may be collectively referred to as a phase decoder. The two reflecting means 207 and 208 are each one polarization orthogonal rotating reflecting means.
Here, the polarization orthogonal rotation reflecting means refers to a reflecting means capable of polarization orthogonal rotation reflecting two orthogonal polarization states of a reflected light pulse, that is, converting each orthogonal polarization state of an incident light pulse into a polarization state orthogonal thereto when reflecting the light pulse.
The front beam splitter 201 is configured to split an incident input optical pulse with any polarization into two optical pulses.
The phase decoder is optically coupled to the pre-splitter 201 for receiving and phase decoding one of the two optical pulses. For convenience, the one optical pulse is hereinafter also referred to as the first optical pulse.
The beam splitter 202 is optically coupled to the front beam splitter 201, and is configured to receive the other of the two optical pulses, split the other optical pulse, and output the split optical pulse for time bit decoding. Here, it should be noted that the beam splitter 202 is optional. It is possible that the further optical pulse is directly output by the pre-splitter 201 for time bit decoding.
The phase decoders constitute an unequal arm michelson interferometer, in which:
the beam splitter 205 is configured to split the first optical pulse into two sub-optical pulses;
The two sub-optical paths are used for respectively transmitting the two sub-optical pulses and realizing the relative delay of the two sub-optical pulses;
the phase modulator 206 is configured to phase modulate the sub-optical pulses passing therethrough according to a quantum key distribution protocol;
two reflecting means 207 and 208 are used to reflect the two sub-optical pulses transmitted via the two sub-optical paths from beam splitter 205 back to the beam splitter, respectively, for beam combining output by the beam splitter.
Since both reflecting means 207 and 208 are polarization orthogonal rotating reflecting means, for each of the two sub-optical pulses obtained by splitting the first optical pulse: the two orthogonal polarization states of the sub-light pulse are polarization-orthogonally rotated for reflection when the sub-light pulse is reflected by a respective one of the two reflecting means, such that each orthogonal polarization state of the sub-light pulse is transformed into a polarization state orthogonal thereto upon reflection by the respective reflecting means.
The relative delay of the two sub-optical pulses can be achieved by adjusting the optical path physical length of either of the two sub-optical paths between beam splitter 205 and the two reflecting means 207 and 208.
The phase modulator 206 may be used to randomly perform either 0 degree phase modulation or 180 degree phase modulation on the light pulses passing therethrough. The phase modulator 206 may be a polarization independent phase modulator or a polarization dependent phase modulator.
The polarization independent phase modulator is adapted to perform identical phase modulation of two orthogonal polarization states of the optical pulse and is therefore referred to as polarization independent. For example, the polarization independent phase modulator may be implemented by two birefringent phase modulators in series or in parallel. Depending on the case, the phase modulation may be achieved by a number of specific means. For example, these means may include: the length of the free space optical path is modulated, or the length of the optical fiber is modulated, or a series or parallel optical waveguide phase modulator or the like is utilized. For example, the desired phase modulation may be achieved by varying the length of the free-space optical path with a motor. For another example, the length of the optical fiber may be modulated by a fiber stretcher using a piezoelectric effect, thereby achieving phase modulation. In addition, the phase modulator may be of other types suitable for voltage control, and the desired phase modulation may be achieved by applying a suitable voltage to the polarization independent phase modulator to perform the same phase modulation on the two orthogonal polarization states of the light pulse.
A polarization dependent phase modulator, such as a birefringent phase modulator, is adapted to apply different tunable phase modulations to two orthogonal polarization states passing therethrough. For example, the birefringent phase modulator may be a lithium niobate phase modulator, and by controlling the voltage applied to the lithium niobate crystal, the phase modulation experienced by each of the two orthogonal polarization states passing through the lithium niobate phase modulator may be controlled and adjusted.
Although fig. 2 shows that a phase modulator is provided on one of the two sub-optical paths, i.e. one of the two sub-optical pulses obtained by splitting the first optical pulse during the splitting to combining of the beam splitter 205 is phase modulated according to the quantum key distribution protocol, it is also possible that a phase modulator is provided at the front end of the beam splitter 205, i.e. the first optical pulse is phase modulated according to the quantum key distribution protocol before it is split. Furthermore, it is also possible to provide a phase modulator, i.e. to phase modulate the incoming one input light pulse, before the front beam splitter 201.
In addition, although a phase decoder having only one phase modulator is shown in fig. 2, it is also possible to provide one phase modulator on each of the two sub-optical paths between the beam splitter 205 and the two reflecting means 207 and 208. In the case where two phase modulators are provided, the difference in the phases modulated by the two phase modulators is determined by the quantum key distribution protocol.
The above-described phase decoder may optionally have the following settings:
a) The two reflecting means 207 and 208 are circularly polarized orthogonal rotating reflecting means, for example, the two reflecting means 207 and 208 each comprise a mirror; beam splitter 205 is a circular polarization maintaining beam splitter.
b) The two reflecting means 207 and 208 are linear polarization orthogonal rotation reflecting means, for example, the two reflecting means 207 and 208 each comprise a reflecting mirror and a quarter wave plate, the reflecting mirror is integrally formed with the quarter wave plate at the rear end of the quarter wave plate, wherein the included angle between the polarization direction of one of the two orthogonal polarization states of each of the two sub-optical pulses and the fast axis or the slow axis of the quarter wave plate is 45 degrees; beam splitter 205 is a line polarization maintaining beam splitter.
c) The two reflecting means 207 and 208 are elliptical polarization orthogonal rotation reflecting means; beam splitter 205 is an elliptical polarization maintaining beam splitter. In this case, a suitable reflecting means may be selected according to the specific elliptical polarization maintaining beam splitter.
d) The two reflecting means 207 and 208 each comprise a 90 degree rotating faraday mirror; beam splitter 205 is a polarization maintaining beam splitter or a non-polarization maintaining beam splitter.
In case of using the settings a), b) or c), advantageously, in the phase decoder, for each of the two sub-optical pulses obtained by splitting the first optical pulse: the two orthogonal polarization states of the sub-optical pulse are kept unchanged during the reflection of the beam splitter beam to the corresponding reflection means and during the reflection of the corresponding reflection means to the beam splitter beam combination. This may be achieved, for example, by configuring the two sub-optical paths as polarization maintaining optical paths and configuring the optical devices on the two sub-optical paths as polarization maintaining optical devices and/or non-birefringent optical devices.
The unequal arm michelson interferometer formed by the phase decoders may be a polarization maintaining unequal arm michelson interferometer or a non-polarization maintaining unequal arm michelson interferometer, depending on the particular configuration.
The decoding apparatus of fig. 2 may further include an optical circulator as needed. The optical circulator may be located at the front end of beam splitter 205. In this case, the input port and the output port of the unequal arm michelson interferometer constituted by the phase decoder may be the same port. The first optical pulse from the pre-splitter 201 may be input from a first port of the optical circulator and output from a second port of the optical circulator to the splitter 205, and the combined beam output from the splitter 205 may be input to a second port of the optical circulator and output from a third port of the optical circulator.
Another preferred embodiment of the present invention is a quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection, as shown in fig. 3, comprising the following components: beam splitters 303 and 304, polarization maintaining beam splitter 307, phase modulator 308, and mirrors 309 and 310. The polarization maintaining beam splitter 307 is a circular polarization maintaining fiber beam splitter.
The splitter 303 acts as a front splitter with one of the two ports 301 and 302 on one side acting as the input port for the device. The beam splitter 304 splits a light pulse from the beam splitter 303 and outputs the split light pulse from the port 305 or 306. Polarization maintaining beam splitter 307 and mirrors 309, 310 form a polarization maintaining unequal arm michelson interferometer, and the two sub-optical paths therebetween are polarization maintaining fiber optical paths. The phase modulator 308 is inserted into either of the two arms of the polarization maintaining unequal arm michelson interferometer. The light pulse input to the polarization-maintaining unequal arm michelson interferometer is decoded and output from port 311.
In operation, an input optical pulse enters the beam splitter 303 through port 301 or 302 of the beam splitter 303 and is split into two optical pulses for transmission by the beam splitter 303. One optical pulse from the beam splitter 303 is input to the beam splitter 304, split by the beam splitter 304, and output via the port 305 or 306 for temporal bit decoding. The other path of light pulse from the beam splitter 303 is input to the polarization maintaining beam splitter 307, and split into two sub-light pulses by the polarization maintaining beam splitter 307. One sub-optical pulse is reflected by the mirror 309 after being randomly modulated with a phase of 0 or 180 degrees by the phase modulator 308, and the other sub-optical pulse is directly transmitted to the mirror 310 via the polarization maintaining fiber and reflected by the mirror 310. The two reflected sub-optical pulses with relative delay are output by the port 311 after being combined by the polarization maintaining beam splitter 307.
Another preferred embodiment of the present invention is a quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection, as shown in fig. 4, comprising the following components: beam splitters 403 and 404, polarization maintaining beam splitter 407, phase modulator 408, and quarter wave plate mirrors 409 and 410. The quarter wave plate reflectors 409 and 410 can be implemented by plating a reflector on the crystal surface of the quarter wave plate, or by plating a reflector on the end face of a polarization maintaining fiber with a phase difference of 90 degrees between the transmission phases of the fast and slow axes. The angle between the fast or slow axis of the polarization maintaining fiber connected to the quarter wave plate mirrors 409 and 410 and the fast or slow axis of the corresponding quarter wave plate is 45 degrees. The polarization maintaining beam splitter 407 is a line polarization maintaining fiber beam splitter.
Beam splitter 403 acts as a front-end beam splitter with one of the two ports 401 and 402 on one side acting as the input port for the device. Beam splitter 404 splits one optical pulse from beam splitter 403 into two paths and outputs it through ports 405 or 406. The polarization maintaining beam splitter 407 and the quarter wave plate reflectors 409 and 410 form a polarization maintaining unequal arm Michelson interferometer, and two sub-optical paths between the polarization maintaining beam splitter 407 and the quarter wave plate reflectors are polarization maintaining optical fiber paths. The phase modulator 408 is inserted into either of the two arms of the polarization maintaining unequal arm michelson interferometer. The light pulses input to the polarization maintaining unequal arm michelson interferometer are decoded and output from port 411.
In operation, an input optical pulse enters beam splitter 403 through port 401 or 402 of beam splitter 403 and is split into two optical pulses for transmission by beam splitter 403. One optical pulse from beam splitter 403 is input to beam splitter 404 and split by beam splitter 404 for output via port 405 or 406 for temporal bit decoding. The other light pulse from beam splitter 403 is input to polarization maintaining beam splitter 407 and split into two sub-light pulses by polarization maintaining beam splitter 407. One sub-optical pulse is reflected by the quarter-wave plate reflecting mirror 409 after being randomly modulated by the phase modulator 408 for 0 degree or 180 degrees, and the other sub-optical pulse is directly transmitted to the quarter-wave plate reflecting mirror 410 through the polarization maintaining fiber and is reflected by the quarter-wave plate reflecting mirror 410. The two reflected sub-optical pulses with relative delay are output by the port 411 after being combined by the polarization-preserving beam splitter 407.
Another preferred embodiment of the present invention is a quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection, as shown in fig. 5, comprising the following components: beam splitters 503 and 504, polarization maintaining beam splitter 507, phase modulator 508, and 90 degree rotating faraday mirrors 509 and 510.
The beam splitter 503 acts as a front beam splitter with one of the two ports 501 and 502 on one side acting as the input port for the device. The beam splitter 504 splits a pulse of light from the beam splitter 503 before outputting it through ports 505 or 506. The polarization-maintaining beam splitter 507 and the 90-degree rotating Faraday mirrors 509 and 510 form a polarization-maintaining unequal arm Michelson interferometer, and two sub-optical paths between the polarization-maintaining beam splitter 507 and the polarization-maintaining unequal arm Michelson interferometer are polarization-maintaining optical fiber paths. The phase modulator 508 is inserted into either of the two arms of the polarization maintaining unequal arm michelson interferometer. The light pulses input to the polarization maintaining unequal arm michelson interferometer are decoded and output from port 511.
In operation, an input optical pulse enters the beam splitter 503 through port 501 or 502 of the beam splitter 503 and is split into two optical pulses by the beam splitter 503 for transmission. One optical pulse from the beam splitter 503 is input to the beam splitter 504, and is split by the beam splitter 504 and output through the port 505 or 506. The other path of light pulse from the beam splitter 503 is input to the polarization maintaining beam splitter 507, and split into two sub-light pulses by the polarization maintaining beam splitter 507. One sub-optical pulse is reflected by the 90-degree rotating Faraday mirror 509 after being randomly modulated with 0-degree or 180-degree phase by the phase modulator 508, and the other sub-optical pulse is directly transmitted to the 90-degree rotating Faraday mirror 510 through the polarization maintaining fiber and is reflected by the 90-degree rotating Faraday mirror 510. The two reflected sub-optical pulses with relative delay are output by the port 511 after being combined by the polarization-maintaining beam splitter 507.
Although the unequal arm michelson interferometer of fig. 5 is described above as using polarization maintaining beam splitter 507 and polarization maintaining fiber optic path, for the unequal arm michelson interferometer, polarization maintaining beam splitter 507 may be replaced with a non-polarization maintaining coupler and/or polarization maintaining fiber optic path may be replaced with a non-polarization maintaining fiber.
For the decoding apparatus of fig. 3 to 5, a photocycler may alternatively be used. For example, for the embodiments of fig. 3-5, an optical circulator may be disposed in the optical path between the pre-splitter and the polarization maintaining splitter such that another optical pulse from the pre-splitter is input from the first port of the optical circulator and output from the second port of the optical circulator to the polarization maintaining splitter, and a combined beam output from the polarization maintaining splitter is input to the second port of the optical circulator and output from the third port of the optical circulator; in this case, the output port and the input port of the unequal arm michelson interferometer may be the same port, and are not limited to the port 311 in fig. 3, the port 411 in fig. 4, and the port 511 in fig. 5.
The terms "beam splitter" and "beam combiner" are used interchangeably herein, and a beam splitter may also be referred to as and function as a beam combiner, and vice versa. As used herein, the term "polarization maintaining fiber optical path" refers to an optical path for transmitting an optical pulse using a polarization maintaining fiber or an optical path formed by connecting polarization maintaining fibers.
The quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection can be configured at the receiving end of the quantum key distribution system and is used for time bit-phase decoding. In addition, the quantum key distribution time bit-phase decoding device based on polarization orthogonal rotation reflection can be configured at the transmitting end of the quantum key distribution system and used for time bit-phase coding.
While the invention has been described in connection with specific embodiments thereof, it is to be understood that these drawings are included in the spirit and scope of the invention, it is not to be limited thereto.
Claims (27)
1. A quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection, the method comprising:
splitting an incident input light pulse with any polarization state into a first light pulse and a second light pulse; and
according to the quantum key distribution protocol, the first path of light pulse is subjected to phase decoding and the second path of light pulse is subjected to time bit decoding,
wherein phase decoding the first optical pulse includes:
Splitting the first path of optical pulse into two sub-optical pulses through a beam splitter; and
transmitting the two sub-optical pulses along two sub-optical paths respectively, and reflecting the two sub-optical pulses back to the beam splitter via two reflecting devices respectively after relative delay to be output by the beam splitter, wherein for each of the two sub-optical pulses:
the two orthogonal polarization states of the sub-light pulse are subjected to polarization orthogonal rotation reflection when the sub-light pulse is reflected by the corresponding reflection device in the two reflection devices, so that after the reflection by the corresponding reflection device, each orthogonal polarization state of the sub-light pulse is converted into a polarization state orthogonal to the sub-light pulse, wherein the phase difference of the transmission of one polarization state of the sub-light pulse by the two sub-light paths in the beam splitting and beam combining process of the beam splitter is exactly equal to the phase difference of the transmission of the other polarization state of the sub-light pulse by the two sub-light paths in the beam splitting and beam combining process of the beam splitter by the polarization orthogonal rotation reflection at the corresponding reflection device,
the input optical pulse before splitting is subjected to phase modulation according to a quantum key distribution protocol through a phase modulator, or the first optical pulse is subjected to phase modulation according to the quantum key distribution protocol through the phase modulator before splitting the first optical pulse, or at least one of the two sub-optical pulses transmitted on the two sub-optical paths is subjected to phase modulation according to the quantum key distribution protocol through the phase modulator in the process of splitting the first optical pulse into the combined beam.
2. The quantum key distribution time bit-phase decoding method based on polarization orthogonal rotation reflection according to claim 1, wherein the two reflection means are circular polarization orthogonal rotation reflection means.
3. The quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection of claim 2, wherein the two reflecting means each comprise a mirror.
4. A quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection according to any of claims 1 to 3, characterized in that the beam splitter is a circular polarization preserving beam splitter.
5. The quantum key distribution time bit-phase decoding method based on polarization orthogonal rotation reflection according to claim 1, wherein the two reflection means are linear polarization orthogonal rotation reflection means.
6. The method for quantum key distribution time bit-phase decoding based on polarization orthogonal rotation reflection according to claim 5, wherein the two reflecting means each comprise a reflecting mirror and a quarter wave plate, the reflecting mirror being integrally formed with the quarter wave plate at a rear end of the quarter wave plate, wherein an included angle between a polarization direction of one of two orthogonal polarization states of each of the two sub-optical pulses and a fast axis or a slow axis of the quarter wave plate is 45 degrees.
7. The quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection of claim 1 or 5 or 6, wherein the beam splitter is a line polarization maintaining beam splitter.
8. The quantum key distribution time bit-phase decoding method based on polarization orthogonal rotation reflection according to claim 1, wherein the two reflection means are elliptical polarization orthogonal rotation reflection means.
9. The quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection of claim 1 or 8, wherein the beam splitter is an elliptical polarization maintaining beam splitter.
10. The quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection according to any of claims 1 to 3, 5, 6 and 8, characterized in that for each of the two sub-optical pulses:
the two orthogonal polarization states of the sub-optical pulse are kept unchanged during the beam splitting by the beam splitter to the reflection of the corresponding reflection means and unchanged during the beam combining by the corresponding reflection means.
11. The quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection of claim 1, wherein the two reflection means each comprise a 90 degree rotating faraday mirror, the beam splitter being a polarization maintaining beam splitter or a non-polarization maintaining beam splitter.
12. The quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection of claim 1, wherein time bit decoding the second path of light pulse comprises:
directly outputting the second path of light pulse for detection; or alternatively
And splitting the second path of light pulse and outputting the split light pulse for detection.
13. The quantum key distribution time bit-phase decoding method based on polarization quadrature rotation reflection of claim 1, wherein phase modulating the light pulses according to the quantum key distribution protocol comprises: the light pulses are randomly either 0-degree phase modulated or 180-degree phase modulated.
14. A quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection, the decoding device comprising:
the front beam splitter is used for splitting one path of input light pulse with any incident polarization state into a first path of light pulse and a second path of light pulse; the method comprises the steps of,
a phase decoder optically coupled to the pre-splitter for phase decoding the first optical pulse,
the phase decoder comprises a first beam splitter, two reflecting devices and two sub-optical paths optically coupled with the first beam splitter and the two reflecting devices, wherein
The first beam splitter is used for splitting the first path of light pulse into two sub-light pulses;
the two sub-optical paths are used for respectively transmitting the two sub-optical pulses and realizing the relative delay of the two sub-optical pulses;
the two reflecting devices are used for respectively reflecting the two sub-optical pulses transmitted by the two sub-optical paths from the first beam splitter back to the first beam splitter to be output by the first beam splitter;
wherein the two reflecting means are configured such that, for each of the two sub-light pulses: the two orthogonal polarization states of the sub-light pulse are subjected to polarization orthogonal rotation reflection when the sub-light pulse is reflected by the corresponding reflection device in the two reflection devices, so that after the reflection by the corresponding reflection device, each orthogonal polarization state of the sub-light pulse is converted into a polarization state orthogonal to the sub-light pulse, wherein the phase difference of the transmission of one polarization state of the sub-light pulse by the two sub-light paths in the beam splitting and beam combining process of the beam splitter is exactly equal to the phase difference of the transmission of the other polarization state of the sub-light pulse by the two sub-light paths in the beam splitting and beam combining process of the beam splitter by the polarization orthogonal rotation reflection at the corresponding reflection device,
Wherein the decoding device is provided with a phase modulator positioned at the front end of the front beam splitter or at the front end of the first beam splitter or on any one of the two sub-optical paths, the phase modulator is used for carrying out phase modulation on the light pulse passing through the phase modulator according to a quantum key distribution protocol,
wherein the pre-splitter outputs the second optical pulse for temporal bit decoding.
15. The quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection of claim 14, wherein the two reflection devices are circular polarization quadrature rotation reflection devices.
16. The quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection of claim 15, wherein the two reflecting means each comprise a mirror.
17. The quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection according to any of claims 14 to 16, wherein the first beam splitter is a circular polarization maintaining beam splitter.
18. The quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection of claim 14, wherein the two reflection devices are linear polarization quadrature rotation reflection devices.
19. The quantum key distribution time bit-phase decoding device based on polarization orthogonal rotation reflection according to claim 18, wherein the two reflecting means each comprise a reflecting mirror and a quarter wave plate, the reflecting mirror being integrally formed with the quarter wave plate at a rear end of the quarter wave plate, wherein the quarter wave plate is configured such that a polarization direction of one of two orthogonal polarization states of each of the two sub-optical pulses is 45 degrees from a fast axis or a slow axis of the quarter wave plate.
20. The quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection of claim 14 or 18 or 19, wherein the first beam splitter is a line polarization maintaining beam splitter.
21. The quantum key distribution time bit-phase decoding device based on polarization orthogonal rotation reflection according to claim 14, wherein the two reflection devices are elliptical polarization orthogonal rotation reflection devices.
22. The quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection of claim 14 or 21, wherein the first beam splitter is an elliptical polarization maintaining beam splitter.
23. The quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection according to any one of claims 14 to 16, 18, 19 and 21, wherein the two sub-optical paths are polarization maintaining optical paths, and the optical devices on the two sub-optical paths are polarization maintaining optical devices and/or non-birefringent optical devices.
24. The quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection of claim 14, wherein the two reflecting means each comprise a 90 degree rotating faraday mirror, the first beam splitter being a polarization maintaining beam splitter or a non-polarization maintaining beam splitter.
25. The quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection of claim 14, wherein the decoding device further comprises a second beam splitter optically coupled to the front beam splitter for receiving the second optical pulse and splitting the second optical pulse for output for time bit decoding.
26. The quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection of claim 14, wherein phase modulating the light pulses according to the quantum key distribution protocol comprises: the light pulses are randomly either 0-degree phase modulated or 180-degree phase modulated.
27. A quantum key distribution system comprising:
the quantum key distribution time bit-phase decoding device based on polarization quadrature rotation reflection according to any one of claims 14 to 26, which is provided at a receiving end of the quantum key distribution system for time bit-phase decoding; and/or
A quantum key distribution time bit-phase decoding apparatus based on polarization quadrature rotation reflection according to any of claims 14 to 26, which is provided at a transmitting end of the quantum key distribution system for time bit-phase encoding.
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| CN110460430A (en) * | 2019-03-08 | 2019-11-15 | 中国电子科技集团公司电子科学研究院 | Quantum key distribution phase codec, corresponding coding and decoding device and system |
| CN110460429A (en) * | 2019-03-08 | 2019-11-15 | 中国电子科技集团公司电子科学研究院 | Quantum key distribution phase codec, corresponding coding and decoding device and system |
| CN110460428B (en) * | 2019-03-08 | 2024-06-25 | 中国电子科技集团公司电子科学研究院 | Quantum key distribution phase codec, corresponding codec device and system |
| CN110460431A (en) * | 2019-03-08 | 2019-11-15 | 中国电子科技集团公司电子科学研究院 | Quantum key distribution phase codec, corresponding coding and decoding device and system |
| CN110460432A (en) * | 2019-03-08 | 2019-11-15 | 中国电子科技集团公司电子科学研究院 | Quantum key distribution phase codec, corresponding coding and decoding device and system |
| CN110460434B (en) * | 2019-06-18 | 2024-08-20 | 中国电子科技集团公司电子科学研究院 | Time phase decoding device and quantum key distribution system comprising same |
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