CN111490825A - Method for transmitting data and simultaneously distributing quantum keys based on anti-resonance hollow-core optical fiber - Google Patents
Method for transmitting data and simultaneously distributing quantum keys based on anti-resonance hollow-core optical fiber Download PDFInfo
- Publication number
- CN111490825A CN111490825A CN202010416966.9A CN202010416966A CN111490825A CN 111490825 A CN111490825 A CN 111490825A CN 202010416966 A CN202010416966 A CN 202010416966A CN 111490825 A CN111490825 A CN 111490825A
- Authority
- CN
- China
- Prior art keywords
- channel
- hollow
- light
- quantum key
- optical fiber
- 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.)
- Granted
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 60
- 238000000034 method Methods 0.000 title claims abstract description 57
- 230000005540 biological transmission Effects 0.000 claims description 54
- 239000000835 fiber Substances 0.000 claims description 39
- 238000009826 distribution Methods 0.000 claims description 34
- 238000004891 communication Methods 0.000 claims description 32
- 230000010287 polarization Effects 0.000 claims description 25
- 230000003287 optical effect Effects 0.000 claims description 19
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 18
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 16
- 229910052710 silicon Inorganic materials 0.000 claims description 16
- 239000010703 silicon Substances 0.000 claims description 16
- 239000011521 glass Substances 0.000 claims description 15
- 238000005253 cladding Methods 0.000 claims description 9
- 238000001514 detection method Methods 0.000 claims description 9
- 230000001419 dependent effect Effects 0.000 claims description 8
- 230000008901 benefit Effects 0.000 description 11
- 230000001427 coherent effect Effects 0.000 description 10
- 238000001069 Raman spectroscopy Methods 0.000 description 8
- 238000010586 diagram Methods 0.000 description 7
- 230000009022 nonlinear effect Effects 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 239000003365 glass fiber Substances 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 239000010453 quartz Substances 0.000 description 4
- 239000013598 vector Substances 0.000 description 4
- 230000003321 amplification Effects 0.000 description 3
- 238000003199 nucleic acid amplification method Methods 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- 230000002269 spontaneous effect Effects 0.000 description 3
- 239000000969 carrier Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000012510 hollow fiber Substances 0.000 description 2
- 230000006855 networking Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 229910000530 Gallium indium arsenide Inorganic materials 0.000 description 1
- 230000005374 Kerr effect Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000002070 nanowire Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000002834 transmittance Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/032—Optical fibres with cladding with or without a coating with non solid core or cladding
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Electromagnetism (AREA)
- Theoretical Computer Science (AREA)
- Computer Security & Cryptography (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Optical Communication System (AREA)
Abstract
The invention discloses a method for transmitting data and distributing quantum keys simultaneously based on anti-resonance hollow-core optical fibers, which comprises the following steps: providing an anti-resonance hollow-core optical fiber with at least two light-transmitting windows, wherein a first channel for transmitting data is transmitted based on one light-transmitting window of the anti-resonance hollow-core optical fiber, and a second channel for transmitting a quantum key for encrypting the data is simultaneously transmitted through the other light-transmitting window of the anti-resonance hollow-core optical fiber.
Description
Technical Field
The invention belongs to the technical field of optical fiber communication, and particularly relates to a method for transmitting data and distributing quantum keys simultaneously based on anti-resonance hollow optical fibers.
Background
The 5G communication network requires data transmission with four characteristics: the flow is large, the time delay is small, the power consumption is low, and the safety is good. To meet these requirements, the performance of optical fibers as a backbone of a communication network needs to be further improved. Over the last forty years, the traditional fiber optic communication systems have primarily used single-core, single-mode silica glass optical fibers. Physical defects such as the inherent nonlinear effect (kerr effect, inelastic scattering, etc.), rayleigh scattering loss, and propagation speed of less than 1.46 times the speed of light of the quartz glass gradually emerge. These intrinsic physical defects limit people to further improve transmission capacity by using higher-order coherent modulation techniques, block the possibility of continuously reducing the transmission loss of optical fibers and saving power consumption, and set an upper limit on the transmission delay of information. For the special requirement of 5G communication application on data security, it is not economical to additionally lay a key agreement channel outside the data transmission network.
As shown in fig. 6, a conventional quantum cryptography optical fiber communication system in the prior art needs a quantum channel and a classical channel to cooperate to complete distribution of a quantum key, and then encrypts transmission data using the quantum key. The quantum channel is responsible for the transmission of weak light, and the classical channel is responsible for the transmission of strong light. The two devices work simultaneously to cause great noise to the single photon detection at the tail end of the quantum channel, because the strong light in the classical channel can change the frequency through the nonlinear action with the optical fiber glass, and then the strong light is transmitted to the wavelength used by the quantum channel, and random noise which cannot be removed is generated at the receiving end of the quantum channel. To solve this problem, time-sharing operation or another method of laying optical fiber links as described above may be adopted, but this increases the cost and complexity of the system, and does not allow intrinsically safe optical communication. In addition, the loss of the ordinary silica glass fiber is large in the 350-900nm wave band, and the ordinary silica glass fiber cannot be used as a quantum channel. And the working wave band of the silicon-based single photon detector with the best comprehensive performance is 350-900 nm. This pair of contradictions is limited by physical mechanisms and cannot be solved.
The above information disclosed in this background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides a method for transmitting data and simultaneously distributing quantum keys based on anti-resonance hollow-core optical fibers, which simultaneously performs low-delay/high-capacity classical data transmission and high-bitrate quantum key distribution in the anti-resonance hollow-core optical fibers with low loss and multiple passbands, and encrypts the transmitted data by using the quantum keys. The hollow optical fiber is a physically novel transmission link, the overlapping degree of an optical field and glass is extremely small and is 3-4 orders of magnitude smaller, and the optical field is mainly overlapped with air. Thus, the nonlinear effects in hollow core fibers are very weak, allowing simultaneous operation without crosstalk between the two channels. Hollow core optical fiber achieves lower transmission loss than quartz glass optical fiber in this band
The invention aims to realize the following technical scheme, and the method for transmitting data and simultaneously distributing quantum keys based on the anti-resonance hollow-core optical fiber comprises the following steps of:
providing an anti-resonance hollow-core optical fiber with at least two light-transmitting windows;
a first channel for transmitting data is transmitted based on one light-passing window of the anti-resonance hollow-core optical fiber;
a second channel carrying a quantum key encrypting the data is simultaneously transported through another clear window of the anti-resonant hollow-core fiber.
Compared with the quartz glass fiber, the core of the hollow fiber is filled with air, so that the hollow fiber has extremely low third-order nonlinear coefficient (which is 3 orders of magnitude smaller than that of the quartz fiber with the same cross section area) and the propagation speed (which is 0.997 times of the light speed) close to the light speed. The Rayleigh scattering coefficient of the air is 2-3 orders of magnitude smaller than that of quartz glass, and the loss of the hollow-core optical fiber after technical improvement is expected to be reduced to a lower degree than that of the quartz optical fiber. The anti-resonance hollow-core optical fiber can simultaneously realize optical transmission with ultralow loss and large enough bandwidth in a plurality of wave bands, and provides a great space for the capacity expansion of an optical fiber communication system. For classical channels, a wide passband means a larger frequency resource, and low non-linearity means that higher order coherent modulation techniques can be used to improve the bandwidth utilization, both of which are of great benefit to the expansion of transmission capacity. For quantum channels, the continuous loss reduction of the anti-resonance hollow-core optical fiber in a visible light waveband is combined with the performance advantage of the silicon-based single photon detector in the visible light waveband, so that higher quantum key coding rate can be obtained. The anti-resonance hollow-core optical fiber has low birefringence and low polarization-dependent loss, and the two physical quantities are influenced by the external environment (elastic-optical coefficient) very little, so that the quantum key distribution operation is facilitated by the polarization state of the optical wave. In addition, because the Raman scattering coefficient of the hollow-core optical fiber is very low, strong laser in a classical data channel cannot influence a quantum key channel, and the two optical fibers can be arranged in the same optical fiber without crosstalk. The quantum key generated by the system itself can encrypt and sign the transmission data. The endogenous secure optical communication can greatly reduce the construction cost and the operation complexity of a secure communication network.
In the method, the position of the light-transmitting window can match 850nm, 1310nm, 1550nm or 2 μm wave bands used for light communication and 350-900nm wave bands used for a silicon-based single photon detector by adjusting the structure size.
In the method, the bandwidth of the light passing window of the anti-resonant hollow-core fiber can be improved by optimizing the thickness and uniformity of the glass wall in the cladding.
In the method, the data transmission can adopt high-order quadrature amplitude modulation, so that the information content contained in each symbol is improved, and the channel transmission capacity is enlarged.
In the method, the quantum key distribution can use a single photon detector based on an avalanche silicon photodiode, so that the detection efficiency is improved, the dark counting rate is reduced, and the quantum key distribution device works at room temperature and is low in price.
In the method, the two light-passing windows can be approximately in a single mode.
In the method, the second channel of the quantum key may have low birefringence and low polarization dependent loss.
In the method, the ratio of the equivalent diameter of the air hole in the cladding of the antiresonant hollow-core fiber to the diameter of the core is approximately 0.68.
In the method, a first channel for data transmission and a second channel for quantum key distribution are in anti-resonance light-passing windows of different orders:
wherein t represents the thickness of the glass wall, n is the refractive index of quartz glass, lambda wavelength, and m is the antiresonance order, and the second channel responsible for quantum key distribution is arranged at the center of the corresponding light-transmitting window.
In the method, a first channel for transmitting data is communicated with a data transmitting and receiving module which comprises a laser, a signal modulator, an optical amplifier, a multiplexer and a detector, and a second channel for transmitting a quantum key for encrypting the data is communicated with a quantum key distribution system which comprises a pulse laser, a variable optical attenuator, a polarizer, a beam splitter, a polarization beam splitter, a half wave plate, a quarter wave plate and a silicon-based single photon detector.
In the method, the data transmitting and receiving module and the quantum key distribution system are combined by a wavelength division multiplexer/demultiplexer to be connected to two ends of a hollow-core optical fiber.
Compared with the prior art, the invention has the following advantages:
the method of the invention simultaneously carries out low-delay/large-capacity classical data transmission and high-coding-rate quantum key distribution in the anti-resonance hollow-core optical fiber with low loss and multiple passbands, and encrypts the transmission data by using the quantum key. For classical channels, a wide passband means a larger frequency resource, and low non-linearity means that higher order coherent modulation techniques can be used to improve the bandwidth utilization, both of which are of great benefit to the expansion of transmission capacity. For quantum channels, the continuous loss reduction of the anti-resonance hollow-core optical fiber in a visible light waveband is combined with the performance advantage of the silicon-based single photon detector in the visible light waveband, so that higher quantum key coding rate can be obtained. The anti-resonance hollow-core optical fiber has low birefringence and low polarization-dependent loss, and the two physical quantities are influenced by the external environment (elastic-optical coefficient) very little, so that the quantum key distribution operation is facilitated by the polarization state of the optical wave. In addition, because the Raman scattering coefficient of the hollow-core optical fiber is very low, strong laser in a classical data channel cannot influence a quantum key channel, and the two optical fibers can be arranged in the same optical fiber without crosstalk. The quantum key generated by the system itself can encrypt and sign the transmission data. The endogenous secure optical communication can greatly reduce the construction cost and the operation complexity of a secure communication network.
Drawings
Various other advantages and benefits of the present invention will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. It is obvious that the drawings described below are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort. Also, like parts are designated by like reference numerals throughout the drawings.
In the drawings:
FIG. 1 is a schematic diagram of the steps of a method for anti-resonant hollow-core fiber-based data transmission while distributing quantum keys, according to one embodiment of the present invention;
FIG. 2 is a schematic diagram of a wavelength division multiplexing/polarization multiplexing/high order QAM coherent communication system based on a method of antiresonant hollow-core fiber based data transmission while distributing quantum keys, in accordance with one embodiment of the present invention;
FIG. 3 is a QAM/16QAM/64QAM constellation diagram of a method of data transmission based on anti-resonant air-core fiber while distributing quantum keys according to one embodiment of the present invention;
FIG. 4 is a schematic diagram of a dual-passband antiresonant air-core fiber transmission loss spectrum for an antiresonant air-core fiber based method of data transmission while distributing quantum keys, according to one embodiment of the present invention;
FIG. 5 is a schematic diagram of a classical optical communication and visible band quantum key distribution hybrid system based on an anti-resonant hollow-core fiber-based method for data transmission while distributing quantum keys according to one embodiment of the present invention;
fig. 6 is a schematic diagram of a conventional quantum cryptography fiber optic communication system.
The invention is further explained below with reference to the figures and examples.
Detailed Description
Specific embodiments of the present invention will be described in more detail below with reference to fig. 1 to 6. While specific embodiments of the invention are shown in the drawings, it should be understood that the invention may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
It should be noted that certain terms are used throughout the description and claims to refer to particular components. As one skilled in the art will appreciate, various names may be used to refer to a component. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. The description which follows is a preferred embodiment of the invention, but is made for the purpose of illustrating the general principles of the invention and not for the purpose of limiting the scope of the invention. The scope of the present invention is defined by the appended claims.
For the purpose of facilitating understanding of the embodiments of the present invention, the following description will be made by taking specific embodiments as examples with reference to the accompanying drawings, and the drawings are not to be construed as limiting the embodiments of the present invention.
For better understanding, fig. 1 is a schematic diagram of the steps of a method according to an embodiment of the present invention, and as shown in fig. 1, a method for data transmission based on an anti-resonant hollow-core fiber and simultaneous distribution of quantum keys comprises the following steps:
an antiresonant hollow-core fiber having at least two light-passing windows is provided,
a first channel for transmitting data is transmitted based on one light-passing window of the anti-resonant hollow-core fiber,
a second channel carrying a quantum key encrypting the data is simultaneously transported through another clear window of the anti-resonant hollow-core fiber.
For further understanding of the present invention, firstly, the benefit of low latency can be obtained by data transmission in the air-core fiber, secondly, the position of the anti-resonant air-core fiber pass-optical window can be adjusted by the structural size design, overlapping with the current communication bands (850nm, 1310nm and 1550nm) and the potential communication bands (2 μm), the bandwidth of the anti-resonant air-core fiber pass-optical window can be increased by optimizing the glass wall thickness and uniformity in the cladding, as shown in fig. 2, the frequency resources that can be utilized by the anti-resonant air-core fiber communication system are very large by the wavelength division multiplexing technique, thirdly, since the non-linear coefficient of the air-core fiber is very small, the channel capacity within a unit frequency band can be amplified by the high-order Quadrature Amplitude Modulation (QAM) coherent communication technique, the Quadrature Amplitude Modulation signal is formed by superimposing two carriers of the same frequency, one carrier is called an I signal, the other is a Q signal, the phase difference between the two carriers is 90 degrees, from the mathematical point of which the I/Q signal can be expressed as a cosine/function, the more the number of the I/Q signal is expressed as a sine constellation function in fig. 3, the number of the signal transmitted signal in the same frequency constellation, the corresponding to the number of the corresponding constellation of the corresponding to the number of the corresponding signal transmitted I constellation, the corresponding to the number of the corresponding to the corresponding QAM constellation, the number of the corresponding to the signal, the corresponding to the number of the corresponding to the signal transmitted QAM symbol of the corresponding to the signal transmitted signal, and the corresponding to the number of the corresponding to the symbol of the corresponding to the corresponding QAM symbol of the QAM, the QAM symbol of the QAM symbol, the QAM symbol of the QAM, the symbol of the symbol, the QAM, the) The order of QAM modulation in the system has reached 2048-211Even higher, the amplification effect of coherent modulation on channel capacity is very significant. In the optical fiber communication system, when QAM order exceeds 128-2, limited by nonlinear effect of quartz glass7The quality of the transmitted signal will rapidly decrease with the transmission distance. In the I/Q coordinate system, the constellation points in the peripheral portion will be significantly distorted, resulting in a so-called non-linear shannon limit of the optical fiber communication capacity. After the polarization multiplexing and coherent multiplexing technologies are comprehensively applied, the upper limit of the frequency band utilization rate of the single-mode quartz optical fiber is about 10 bit/s/Hz. After the solid-core optical fiber is replaced by the hollow-core optical fiber, the influence of the nonlinear effect is greatly reduced, the frequency band utilization rate can be continuously increased by increasing the QAM modulation order, and the transmission capacity of the system is increased.
In order to achieve both classical data transmission and quantum key distribution in one anti-resonant hollow-core fiber, one can arrange two tasks in two or more clear windows. For the anti-resonant hollow-core fiber, a sufficiently large bandwidth can be obtained in each light-transmitting window by adjusting the thickness of the glass wall in the cladding and ensuring uniform thickness. As shown in fig. 4, the antiresonant hollow-core fiber also allows the characteristics of single mode and low transmission loss to be maintained in each light-passing window, which is very important for improving the data transmission quality and quantum key generation efficiency.
A light-transmitting window of the anti-resonance hollow-core optical fiber is arranged in a visible light wave band, so that the quantum key channel can use a silicon-based single photon detector. The silicon-based single-photon detector has the advantages of low price, stable performance, capability of working at room temperature, 1-2 orders of magnitude higher detection sensitivity and 3 orders of magnitude lower dark current noise than the near-infrared InGaAs single-photon detector. Compared with a superconducting nanowire single-photon detector, the silicon-based single-photon detector has the rolling advantage in the aspects of price and environmental friendliness. At present, the transmission loss of the anti-resonance hollow-core fiber in red and green light bands is reduced to be below 4dB/km, which exceeds the Rayleigh scattering loss of the quartz glass fiber in the band. Therefore, the method can obtain the optimal comprehensive performance of photon transmission and single photon detectors, and obviously improve the coding efficiency of the quantum key distribution system. Meanwhile, the visible light band is also the working band of many Reed-Bo atoms. The quantum communication system of the waveband can provide convenience for quantum information storage and networking.
In terms of quantum key distribution functionality, it is first necessary to ensure that the channel has as low birefringence and polarization dependent loss as possible. The lowest wavelength of these two physical quantities in the anti-resonant hollow-core fiber is at the center of the light-passing window, and here is also the wavelength with the lowest transmission loss. Secondly, when one optical fiber simultaneously transmits the classical light pulse and the single-photon pulse, the influence of the spontaneous raman scattering noise caused by the classical signal light on the single-photon channel needs to be considered. Since the raman scattering coefficient of air is very low, the raman scattering coefficient in hollow core fiber, like its third order nonlinear coefficient, is determined by the degree of overlap of the mode field with the glass wall, and will be at least 3 orders of magnitude lower than that of silica fiber, which is very advantageous for eliminating spontaneous raman scattering noise. Therefore, the anti-resonance hollow-core optical fiber communication system provided by the invention can ensure that the classical channel and the quantum channel are not interfered with each other and are arranged in one optical fiber, and is more suitable for the requirement of an endogenous safety mode on a communication link.
The invention provides a method for simultaneously carrying out classical data transmission and quantum key distribution by using different light-transmitting windows of an anti-resonance hollow-core optical fiber, which simultaneously considers the requirements of high capacity, low time delay and potential low loss of the former and the requirements of low birefringence, low polarization dependence loss, high detection efficiency, low dark counting rate and low spontaneous Raman scattering noise of the latter. The working band of the former can be overlapped with a commercial optical fiber communication system, and the working band of the latter can be arranged in a visible light band and matched with the optimal single photon detection technology and quantum storage technology. The former requires extremely high laser power, the latter requires extremely low laser power, and two sets of transmission systems coexist in the same optical fiber. Such stringent requirements are only achieved in antiresonant hollow-core fibers.
The central wavelength of each light-passing window in the anti-resonance hollow-core optical fiber is determined by the thickness of the glass wall, the reduction of transmission loss can be realized by increasing the number of layers of the cladding glass wall, the single-mode light guiding can be realized by selecting the number and the size of the glass tubes, and the low birefringence and the low polarization dependent loss can be realized by arranging the wavelength at the center of the light-passing window. After the anti-resonance hollow optical fiber with corresponding attributes is designed and processed, commercial optical communication equipment and quantum key distribution equipment are connected to two ends of the optical fiber, and data in a classical channel is encrypted by using a key generated in a quantum channel, so that a set of optical fiber communication system with high capacity, low time delay, low power consumption and high confidentiality is formed.
In a preferred embodiment of the method, the hollow-core fiber is an antiresonant hollow-core fiber. The anti-resonance hollow-core optical fiber with the multilayer glass wall structure can simultaneously realize low-loss, low-time-delay, broadband, single-mode, low-birefringence, low polarization-dependent loss and low-nonlinearity light guiding in a plurality of windows from visible light to near-infrared wave bands.
In a preferred embodiment of the method, the position of the light-transmitting window can match the 850nm, 1310nm, 1550nm or 2 μm wave band used for optical communication and the 350-900nm wave band used for the silicon-based single photon detector by adjusting the structural size.
In a preferred embodiment of the method, the bandwidth of the light transmission window of the antiresonant hollow-core fiber can be increased by optimizing the thickness and uniformity of the glass wall in the cladding.
In a preferred embodiment of the method, the data transmission may adopt high-order quadrature amplitude modulation, so as to increase the amount of information contained in each symbol and expand the channel transmission capacity.
In the preferred embodiment of the method, the quantum key distribution can use a single photon detector based on an avalanche silicon photodiode, so that the detection efficiency is improved, the dark counting rate is reduced, and the quantum key distribution method is low in cost and works at room temperature.
In a preferred embodiment of the method, the two light transmission windows can be approximately single-mode.
In a preferred embodiment of the method, the second channel of the quantum key may have low birefringence and low polarization dependent loss.
In a preferred embodiment of the method, the ratio of the equivalent diameter of the air holes in the cladding of the antiresonant hollow-core fiber to the core diameter is approximately 0.68.
In a preferred embodiment of the method, the first channel of data transmission and the second channel of quantum key distribution are in anti-resonant clear windows of different orders:
wherein t represents the thickness of the glass wall, n is the refractive index of the quartz glass, lambda is the wavelength, and m is the order of the antiresonance. And the second channel responsible for quantum key distribution is arranged in the center of the corresponding light-transmitting window.
In a preferred embodiment of the method, a first channel for transmitting data communicates with a data transmitting and receiving module, which includes a laser, a signal modulator, an optical amplifier, a multiplexer and a detector, and a second channel for transmitting a quantum key for encrypting the data communicates with a quantum key distribution system, which includes a pulse laser, a variable optical attenuator, a polarizer, a beam splitter, a polarization beam splitter, a half-wave plate, a quarter-wave plate and a silicon-based single photon detector.
In one embodiment, the quantum key distribution system includes a BB84 (single photon class) protocol. The protocol encodes a random quantum key with four linear polarization states of a single photon (BB84 states). The horizontal and vertical directions constitute one set of orthogonal polarization bases (Z-base), and the 45 DEG and 135 DEG directions constitute the other set of orthogonal polarization bases (X-base). The two groups of polarization bases are not orthogonal, and the projection probability is 50%. The operation of the BB84 protocol is as follows:
alice randomly generates a group of {0, 1} bits and a polarization basis vector { Z, X } sequence, and accordingly a corresponding single photon polarization state is prepared and sent to Bob;
after receiving the photons, Bob measures according to the polarization base randomly selected by the Bob;
after the measurement is finished, comparing the preparation basis and the measurement basis of two persons in a classical channel by Alice and Bob, and discarding data obtained under the condition that two sets of basis vectors are selected to be inconsistent;
under the conditions that no loss exists and no eavesdropping exists in the transmission and detection processes of photons, the quantum mechanical law can ensure that random keys reserved by Alice and Bob are completely the same;
since an eavesdropper cannot know in advance what polarization basis Alice and Bob have selected, only one set of polarization basis can be guessed to measure and re-emit the intercepted single photons. Once misguessing occurs, Alice and Bob can estimate the bit error rate by comparing a part of original keys in a public channel, find out the wiretapping behavior and estimate the information loss caused by the wiretapping behavior;
by taking into account the energy loss during photon transmission/detection and the information loss caused by possible eavesdropping, Alice and Bob can analyze the bit error rate by comparing a part of the keys, perform some data processing (such as data error correction and privacy amplification) and compress a part of the possibly unsafe key bits. The part of the key left can prove absolute safety.
In one embodiment, the quantum key distribution system comprises a quantum key distribution protocol using a shared entangled photon pair, two communication parties obtain one photon in the entangled photon pair to respectively measure, the security of the key is analyzed by using the quantum relevance ratio between the entangled photon pair, and subsequent data processing is performed. The entangled photon pairs are respectively sent to Alice and Bob, and the two persons respectively measure the received photons in respective randomly selected basis vectors { Z, X }; comparing the measurement basis in the public channel by Alice and Bob, discarding the result measured in different basis vectors by using a method similar to the BB84 protocol, carrying out error rate analysis on a part of the reserved original key, terminating the protocol if the error rate is too high, and restarting; and performing subsequent data processing, such as data error correction and privacy amplification, on the other part of the original key to obtain a final security key.
In one embodiment, the quantum key distribution system includes a spoof state protocol, wherein,
alice randomly prepares several phase-randomized weak coherent light pulses with different light intensities, wherein one is a signal state for generating a secret key, and the other is a decoy state, and the signal state and the decoy state jointly form a mixed state in which the photon number meets Poisson distribution. Bob measures and records according to the protocol;
after the measurement is finished, the Alice publishes the used decoy state information to Bob in the open channel, and the Bob carries out classified statistics on the measured result according to different decoy state intensities to obtain the counting rate and the error rate;
simultaneously establishing an equation set corresponding to the results to obtain the gain and phase error rate of the single photon state part, and calculating the obtained safe code forming rate according to a G LL P formula;
in the photon count separation attack, in order for an eavesdropper to keep the photon count distribution of the optical pulses reaching Bob consistent with that in the case of no eavesdropping, the adjustment of the transmittance of the multiphoton state depends on the light intensity of the weak coherent light used by Alice and the channel loss. Since an eavesdropper cannot know in advance which intensity of weak coherent light the intercepted light pulse belongs to, the passing rate of photons cannot be adjusted differently according to the light intensity, and eavesdropping behavior cannot be concealed.
In a preferred embodiment of the method, as shown in fig. 5, the data transmission and reception module and the quantum key distribution system are combined via a wavelength division multiplexer/demultiplexer to connect to both ends of the hollow-core fiber.
The anti-resonance hollow-core optical fiber has extremely low Raman scattering coefficient, and can ensure no interference between a classical channel and a quantum channel; the anti-resonance hollow-core optical fiber has the characteristics of broadband and low nonlinearity, and can ensure that the frequency resource and the frequency band utilization rate of data transmission are high enough; the loss of the anti-resonance hollow-core optical fiber in a visible light wave band can be reduced to a degree lower than the Rayleigh scattering loss of quartz, and the high sensitivity and the low dark counting rate of the silicon-based single photon detector can realize the high efficiency of a quantum key distribution system; the quantum key technology has absolute safety which can be proved by mathematics and simplicity of an endogenous safety mode, and realizes low-cost confidential data communication and networking.
Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments and application fields, and the above-described embodiments are illustrative, instructive, and not restrictive. Those skilled in the art, having the benefit of this disclosure, may effect numerous modifications thereto without departing from the scope of the invention as defined by the appended claims.
Claims (10)
1. A method for data transmission based on anti-resonant hollow-core fiber while distributing quantum keys, the method comprising the steps of:
providing an anti-resonance hollow-core optical fiber with at least two light-transmitting windows;
a first channel for transmitting data is transmitted based on one light-passing window of the anti-resonance hollow-core optical fiber;
a second channel carrying a quantum key encrypting the data is simultaneously transported through another clear window of the anti-resonant hollow-core fiber.
2. The method as claimed in claim 1, wherein the position of the light-passing window can be adjusted to match 850nm, 1310nm, 1550nm or 2 μm wavelength band used for optical communication and 350-900nm wavelength band used for silicon-based single photon detector by adjusting the structure size.
3. The method of claim 1, wherein the bandwidth of the light-passing window of the antiresonant hollow-core fiber can be increased by optimizing the thickness and uniformity of the glass wall in the cladding.
4. The method of claim 1, wherein the data transmission can adopt high-order quadrature amplitude modulation, so as to increase the amount of information contained in each symbol and enlarge the channel transmission capacity.
5. The method of claim 1, wherein said distributed quantum key can use single photon detectors based on avalanche silicon photodiodes, improving detection efficiency, reducing dark count rate, operating at room temperature and being inexpensive.
6. The method of claim 1, wherein the two light-passing windows are approximately single-mode.
7. The method of claim 1, wherein the second channel of the quantum key is low birefringent and low polarization dependent loss.
8. The method of claim 1, wherein the ratio of the equivalent diameter of the air holes in the cladding to the core diameter of the antiresonant hollow-core fiber is approximately 0.68.
9. The method of claim 1, wherein the first channel of data transmission and the second channel of quantum key distribution are in anti-resonant clear windows of different orders:
wherein t represents the thickness of the glass wall, n is the refractive index of quartz glass, lambda wavelength, and m is the antiresonance order, and the second channel responsible for quantum key distribution is arranged at the center of the corresponding light-transmitting window.
10. The method of claim 1, wherein a first channel communicating data transmission and reception modules that transmit data, including a laser, a signal modulator, an optical amplifier, a multiplexer, and a detector, and a second channel communicating quantum key distribution system that transmits a quantum key that encrypts the data, including a pulsed laser, a variable optical attenuator, a polarizer, a beam splitter, a polarization beam splitter, a half wave plate, a quarter wave plate, and a silicon-based single photon detector.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010416966.9A CN111490825B (en) | 2020-05-15 | 2020-05-15 | Method for transmitting data and simultaneously distributing quantum keys based on anti-resonance hollow-core optical fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010416966.9A CN111490825B (en) | 2020-05-15 | 2020-05-15 | Method for transmitting data and simultaneously distributing quantum keys based on anti-resonance hollow-core optical fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111490825A true CN111490825A (en) | 2020-08-04 |
| CN111490825B CN111490825B (en) | 2021-06-08 |
Family
ID=71796791
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010416966.9A Active CN111490825B (en) | 2020-05-15 | 2020-05-15 | Method for transmitting data and simultaneously distributing quantum keys based on anti-resonance hollow-core optical fiber |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111490825B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114024671A (en) * | 2021-11-05 | 2022-02-08 | 深圳市联洲国际技术有限公司 | Key generation method and device and computer-readable storage medium |
| EP4277166A1 (en) * | 2022-05-13 | 2023-11-15 | British Telecommunications public limited company | Electromagnetic field detector |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2264917A1 (en) * | 2008-03-10 | 2010-12-22 | Sumitomo Electric Industries, Ltd. | Optical communication system |
| CN107276753A (en) * | 2017-06-27 | 2017-10-20 | 浙江九州量子信息技术股份有限公司 | The quantum key distribution system and method for a kind of channel multiplexing |
| CN207706189U (en) * | 2017-09-06 | 2018-08-07 | 安徽问天量子科技股份有限公司 | Quantum light and the total fine transmitting device of classical light |
| CN209517162U (en) * | 2019-05-06 | 2019-10-18 | 科大国盾量子技术股份有限公司 | A kind of palarization multiplexing two-way quantum key dissemination system |
| CN110830121A (en) * | 2019-11-01 | 2020-02-21 | 国开启科量子技术(北京)有限公司 | Classical channel and quantum channel wavelength division multiplexing system and method |
-
2020
- 2020-05-15 CN CN202010416966.9A patent/CN111490825B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2264917A1 (en) * | 2008-03-10 | 2010-12-22 | Sumitomo Electric Industries, Ltd. | Optical communication system |
| CN107276753A (en) * | 2017-06-27 | 2017-10-20 | 浙江九州量子信息技术股份有限公司 | The quantum key distribution system and method for a kind of channel multiplexing |
| CN207706189U (en) * | 2017-09-06 | 2018-08-07 | 安徽问天量子科技股份有限公司 | Quantum light and the total fine transmitting device of classical light |
| CN209517162U (en) * | 2019-05-06 | 2019-10-18 | 科大国盾量子技术股份有限公司 | A kind of palarization multiplexing two-way quantum key dissemination system |
| CN110830121A (en) * | 2019-11-01 | 2020-02-21 | 国开启科量子技术(北京)有限公司 | Classical channel and quantum channel wavelength division multiplexing system and method |
Non-Patent Citations (1)
| Title |
|---|
| JICHAO ZANG 等: "Multiple-Hollow-Core Anti-resonant Fiber", 《2018 23RD OPTO-ELECTRONICS AND COMMUNICATIONS CONFERENCE (OECC)》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114024671A (en) * | 2021-11-05 | 2022-02-08 | 深圳市联洲国际技术有限公司 | Key generation method and device and computer-readable storage medium |
| CN114024671B (en) * | 2021-11-05 | 2024-03-29 | 深圳市联洲国际技术有限公司 | Method and device for generating secret key, and computer readable storage medium |
| EP4277166A1 (en) * | 2022-05-13 | 2023-11-15 | British Telecommunications public limited company | Electromagnetic field detector |
| WO2023217473A1 (en) * | 2022-05-13 | 2023-11-16 | British Telecommunications Public Limited Company | Electromagnetic field detector |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111490825B (en) | 2021-06-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Vagniluca et al. | Efficient time-bin encoding for practical high-dimensional quantum key distribution | |
| US11930106B2 (en) | Quantum communication system that switches between quantum key distribution (QKD) protocols and associated methods | |
| CN108650088B (en) | Quantum communication device and method comprising at least three parties | |
| US20130089204A1 (en) | Quantum encrypted data transmission in optically-amplified wdm communications | |
| US20100034390A1 (en) | Differential Phase Shift Keying Quantum Key Distribution | |
| CN108365953A (en) | Adaptive differential phase shift quantum key dissemination system based on deep neural network and its implementation | |
| Liu et al. | Multicarrier multiplexing continuous-variable quantum key distribution at terahertz bands under indoor environment and in inter-satellite links communication | |
| CN111147243B (en) | LLO-based single wavelength quantum and classical communication simultaneous transmission method | |
| CN111490825B (en) | Method for transmitting data and simultaneously distributing quantum keys based on anti-resonance hollow-core optical fiber | |
| CN112422226B (en) | Key generation method and device based on polarization mode dispersion of optical fiber communication link | |
| AU2022201032B2 (en) | Long-distance quantum key distribution | |
| CN112702162B (en) | One-dimensional continuous variable quantum key distribution system based on discrete state and implementation method thereof | |
| Kong et al. | Impact of classical modulation signals on quantum key distribution over multicore fiber | |
| Lei et al. | Long-haul and high-speed key distribution based on one-way non-dual arbitrary basis transformation in optical fiber link | |
| Zhang et al. | Physical layer security based on chaotic spatial symbol transforming in fiber-optic systems | |
| Kong et al. | Core and wavelength allocation schemes for noise suppression in quantum key distribution over multicore fiber | |
| Mlejnek et al. | Modeling high quantum bit rate QKD systems over optical fiber | |
| CN213879847U (en) | Multi-user double-field QKD network system based on orbital angular momentum | |
| Tan et al. | A novel realization of PSK quantum-noise randomized cipher system based on series structure of multiple phase modulators | |
| Chen et al. | Research on key distribution and encryption control system of optical network physical layer | |
| Wang et al. | A secure authentication scheme based on SNR of optical fiber communication channel | |
| Sun et al. | Reference-frame-independent quantum key distribution of wavelength division multiplexing with multiple quantum channels | |
| CN108880809B (en) | Block chain data encryption system based on continuous variable quantum key distribution and implementation method thereof | |
| CN110351070B (en) | Quantum key distribution system and method based on Y waveguide | |
| CN113422682B (en) | Physical layer security key distribution method based on dispersion balance and cellular automata |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |