CN115001679B - CVQKD system and distribution method based on silicon-based integrated chip - Google Patents
CVQKD system and distribution method based on silicon-based integrated chip Download PDFInfo
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title claims abstract description 86
- 229910052710 silicon Inorganic materials 0.000 title claims abstract description 86
- 239000010703 silicon Substances 0.000 title claims abstract description 86
- 238000000034 method Methods 0.000 title claims abstract description 20
- 230000003287 optical effect Effects 0.000 claims abstract description 117
- 238000012545 processing Methods 0.000 claims abstract description 89
- 239000013307 optical fiber Substances 0.000 claims abstract description 24
- 230000010355 oscillation Effects 0.000 claims abstract description 20
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- 230000010354 integration Effects 0.000 claims abstract description 8
- 230000008569 process Effects 0.000 claims abstract description 7
- 230000010287 polarization Effects 0.000 claims description 74
- 230000005540 biological transmission Effects 0.000 claims description 18
- 230000008878 coupling Effects 0.000 claims description 13
- 238000010168 coupling process Methods 0.000 claims description 13
- 238000005859 coupling reaction Methods 0.000 claims description 13
- 230000001427 coherent effect Effects 0.000 claims description 11
- 238000012544 monitoring process Methods 0.000 claims description 10
- 238000005516 engineering process Methods 0.000 claims description 7
- 239000004065 semiconductor Substances 0.000 claims description 7
- 230000008033 biological extinction Effects 0.000 claims description 4
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- 230000017525 heat dissipation Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
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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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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
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- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
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Abstract
The invention discloses a CVQKD system based on a silicon-based integrated chip, which comprises a light source processing end, a quantum key sending end, an optical fiber channel and a quantum key receiving end; the light source processing end generates signal light and transmits the quantum key transmitting end; the quantum key transmitting end receives the signal light, processes the signal light and transmits the processed signal light to the quantum key receiving end through the optical fiber channel; the quantum key receiving end receives the optical signal and performs subsequent processing to finish the data receiving. The invention also discloses a distributing method of the CVQKD system based on the silicon-based integrated chip. The invention can meet the requirements of various continuous quantum key distribution protocols by adopting a protocol-adjustable unit architecture; the local oscillation light for detection is generated at the receiving end, so that calibration attack can be avoided; the invention has high integration level, good stability and flexible function.
Description
Technical Field
The invention belongs to the technical field of quantum communication, and particularly relates to a CVQKD system based on a silicon-based integrated chip and a distribution method.
Background
With the development of economic technology and the improvement of living standard of people, the data security of the communication process has been increasingly paid attention to. Quantum key distribution is one of the development hotspots in the field of quantum communications. QKD (quantum key distribution ) belongs to a distributed key that utilizes the hessian-burg uncertainty principle and the quantum unclonable theorem, guaranteeing the security of the distributed key.
Quantum key distribution can be generally divided into two forms, discrete quantum key distribution (DVQKD) and continuous quantum key distribution (CVQKD). Compared with DVQKD, the CVQKD light source can be prepared by selecting relatively simple coherent light, a homodyne detector with high detection efficiency can be used at a receiving end, and compared with a single photon detector, the CVQKD light source has the advantages of low manufacturing cost and the like. In addition, CVQKD is compatible with modern optical communication systems, easy to operate and test, and low in cost.
Today's traditional semiconductor industry has been subject to physical limitations and approaches that rely on shrinking feature sizes to increase chip integration are about to fail. Silicon photonics technology has become one of the potential technologies for prolonging the life of moore's law by virtue of its special advantages in terms of energy consumption, bandwidth, operation rate, heat dissipation, volume size, etc. The miniaturized and low-cost QKD system based on the silicon photon technology integrates optoelectronic devices with various functions on the same silicon substrate to form a novel integrated QKD chip, which is the final solution of the next-generation QKD network.
Some students in the last two years construct a QKD system on a silicon-based photon platform, but most of the currently studied silicon photon integrated chips aim at a single DVQKD system or CVQKD system, the chip integration level is low, the function implementation is inflexible, and the currently lacking silicon-based chip integrated CVQKD system capable of realizing multiple key distribution protocols in a coordinated manner.
Disclosure of Invention
One of the purposes of the invention is to provide a CVQKD system based on a silicon-based integrated chip, which has high integration level, good reliability and flexible function.
It is a second object of the present invention to provide a distribution method implemented by the CVQKD system based on a silicon-based integrated chip.
The CVQKD system based on the silicon-based integrated chip comprises a light source processing end, a quantum key sending end, an optical fiber channel and a quantum key receiving end; the light source processing end, the quantum key sending end, the optical fiber channel and the quantum key receiving end are sequentially connected in series; the light source processing end is used for generating signal light and transmitting the signal light to the quantum key sending end; the quantum key sending end is used for receiving the signal light, processing the signal light and sending the processed signal light to the quantum key receiving end through the optical fiber channel; the quantum key receiving terminal is used for receiving the optical signals and carrying out subsequent processing, so that data receiving is completed.
The light source processing end comprises a processing end laser, a processing end ultra-stable resonant cavity, a processing end first amplitude modulator and a processing end first polarization beam splitter; the processing end laser, the processing end ultra-stable resonant cavity, the processing end first amplitude modulator and the processing end first polarization beam splitter are sequentially connected in series; the processing end laser is used for generating continuous light wave signals and inputting the continuous light wave signals into the processing end ultra-stable resonant cavity; the processing end ultra-stable resonant cavity is used for outputting a feedback signal to the processing end laser, ensuring that the processing end laser generates coherent light with narrow linewidth and no phase noise, and transmitting the coherent light to the processing end first amplitude modulator; the processing end first amplitude modulator is used for weakening amplitude noise of received coherent light and transmitting continuous light waves after noise suppression to the processing end first polarization beam splitter; the processing end first polarization beam splitter is used for dividing received continuous light waves into two beams, wherein 1% of the beams are signal light, and 99% of the beams are pilot signal light; and transmits the signal light and the pilot signal light to the quantum key transmitting terminal.
The processing end laser is a narrow linewidth semiconductor laser.
The quantum key transmitting end comprises a transmitting end first isolator, a transmitting end first adjustable optical attenuator, a transmitting end second adjustable optical attenuator, a transmitting end first beam splitter, a transmitting end first amplitude modulator, a transmitting end second beam splitter, a transmitting end silicon-based phase shifter, a transmitting end third adjustable optical attenuator, a transmitting end polarization beam combiner, a transmitting end two-dimensional grating coupler, a transmitting end acousto-optic modulator and a transmitting end second isolator; the output end of the first isolator of the transmitting end is connected with the input ends of the first adjustable optical attenuator of the transmitting end and the second adjustable optical attenuator of the transmitting end; the output end of the first adjustable optical attenuator at the transmitting end is connected with the input end of the first beam splitter at the transmitting end; the output end of the first beam splitter of the transmitting end is simultaneously connected with the input ends of the first amplitude modulator of the transmitting end and the second amplitude modulator of the transmitting end; the output end of the first amplitude modulator at the transmitting end and the output end of the second amplitude modulator at the transmitting end are simultaneously connected with the input end of the second beam splitter at the transmitting end; the output end of the second beam splitter at the transmitting end is sequentially connected with a silicon-based phase shifter at the transmitting end, a third adjustable optical attenuator at the transmitting end, a polarization beam combiner at the transmitting end and a two-dimensional grating coupler at the transmitting end in series; the transmitting end second adjustable optical attenuator, the transmitting end acousto-optic modulator and the transmitting end second isolator are sequentially connected in series; the output end of the second isolator of the transmitting end is connected with the input end of the polarization beam combiner of the transmitting end; the first isolator of the transmitting end is used for isolating input signals, transmitting the input signal light to the first adjustable optical attenuator of the transmitting end, and transmitting the input pilot signal light to the second adjustable optical attenuator of the transmitting end; the first adjustable optical attenuator at the transmitting end is used for adjusting the intensity of the received signal light and inputting the adjusted signal light to the first beam splitter at the transmitting end; the second adjustable optical attenuator at the transmitting end is used for adjusting the intensity of the received pilot signal light and inputting the adjusted pilot signal light to the acousto-optic modulator at the transmitting end; the first beam splitter at the transmitting end is used for splitting the received signal light and outputting the split signals to the first amplitude modulator at the transmitting end and the second amplitude modulator at the transmitting end at the same time; the transmitting end first amplitude modulator is used for carrying out amplitude modulation on the received signal and transmitting the modulated signal to the transmitting end second beam splitter; the transmitting end second amplitude modulator is used for carrying out amplitude modulation on the received signal and transmitting the modulated signal to the transmitting end second beam splitter; the second beam splitter at the transmitting end is used for combining the received signals and transmitting the combined signals to the silicon-based phase shifter at the transmitting end; the first beam splitter at the transmitting end, the first amplitude modulator at the transmitting end, the second amplitude modulator at the transmitting end and the second beam splitter at the transmitting end form an equal-arm Mach-Zehnder modulator; the transmitting end silicon-based phase shifter is used for enhancing the phase factor of the received optical signal and outputting the optical signal to the transmitting end third adjustable optical attenuator; the third adjustable optical attenuator at the transmitting end is used for adjusting the intensity of the received optical signal so as to maximize the key rate and transmitting the adjusted optical signal to the polarization beam combiner at the transmitting end; the transmitting end acousto-optic modulator is used for performing frequency up-shifting on the received pilot signal light and transmitting the up-shifted signal to the transmitting end second isolator; the second isolator at the transmitting end is used for isolating the received signals and transmitting the signals to the polarization beam combiner at the transmitting end; the transmitting end polarization beam combiner is used for combining the received two paths of optical signals and outputting the two paths of optical signals to the transmitting end two-dimensional grating coupler; the transmitting end two-dimensional grating coupler is used for coupling the received optical signals into the waveguide and transmitting the optical signals to the quantum key receiving end through the optical fiber channel.
The transmitting-end acousto-optic modulator is an upward-shifting acousto-optic modulator; the light source processing end except the processing end laser, the quantum key sending end except the sending end acousto-optic modulator and the quantum key receiving end are integrated on the same silicon-based photon chip by adopting a silicon photon integration technology.
The quantum key receiving end comprises a receiving end polarization controller, a receiving end filter, a receiving end two-dimensional grating coupler, a receiving end first polarization beam splitter, a receiving end isolator, a receiving end acousto-optic modulator, a receiving end 90-degree mixer, a receiving end first beam splitter, a receiving end first amplitude modulator, a receiving end second beam splitter, a receiving end laser, a receiving end second amplitude modulator, a receiving end third beam splitter, a receiving end silicon-based phase modulator, a receiving end homodyne detector and a receiving end balanced homodyne detector; the receiving end polarization controller, the receiving end filter, the receiving end two-dimensional grating coupler and the receiving end first polarization beam splitter are sequentially connected in series; the first output end of the receiving end first polarization beam splitter is connected with the input end of the receiving end first beam splitter, and the second output end of the receiving end first polarization beam splitter is connected with the input end of the receiving end isolator; the first output end of the first beam splitter of the receiving end is connected with the output end of the first amplitude modulator of the receiving end, and the output end of the first amplitude modulator of the receiving end is connected with the balanced homodyne detector of the receiving end; the second output end of the receiving end first beam splitter is connected with the first input end of the receiving end second beam splitter; the output end of the receiving end isolator is connected with the input end of the receiving end acousto-optic modulator, and the output end of the receiving end acousto-optic modulator is connected with the first input end of the receiving end 90-degree mixer; the receiving end laser, the receiving end second amplitude modulator and the receiving end third beam splitter are sequentially connected in series; the first output end of the receiving end third beam splitter is connected with the input end of the receiving end silicon-based phase modulator, and the output end of the receiving end silicon-based phase modulator is connected with the second input end of the receiving end second beam splitter; the second output end of the receiving end third beam splitter is connected with the second input end of the receiving end 90-degree mixer; the output end of the receiving end second beam splitter and the output end of the receiving end 90-degree mixer are both connected with a receiving end homodyne detector; the receiving end polarization controller is used for supplementing deflection of the polarization direction of the coupling light emitted by the optical fiber channel to the received optical signal and sending the supplemented optical signal to the receiving end filter; the receiving end filter is used for filtering the received optical signals and sending the filtered optical signals to the receiving end two-dimensional grating coupler; the receiving end two-dimensional grating coupler is used for coupling the received optical signals into the silicon waveguide and transmitting the optical signals to the receiving end first polarization beam splitter; the receiving end first polarization beam splitter is used for carrying out polarization separation on the received optical signals to obtain pilot signals and coded signals; the pilot signal is sent to the isolator of the receiving end, and the coded signal is sent to the first beam splitter of the receiving end; the receiving end isolator is used for isolating the received pilot signals and then sending the pilot signals to the receiving end acousto-optic modulator; the receiving end acousto-optic modulator is used for performing frequency movement on the received signal and transmitting the moved signal to the 90-degree mixer at the receiving end; the receiving end laser is used for generating local oscillation light and outputting the local oscillation light to the receiving end second amplitude modulator; the second amplitude modulator at the receiving end is used for carrying out amplitude modulation on the received local oscillation light, generating optical pulses and sending the optical pulses to the third beam splitter at the receiving end; the receiving end third beam splitter is used for splitting the received light pulse into two beams, 1% of the light pulse is input to the receiving end 90-degree mixer, and 99% of the light pulse is input to the receiving end silicon-based phase modulator; the 90-degree mixer at the receiving end is used for mixing the received optical signals and outputting the mixed signals to the homodyne detector at the receiving end to provide phase offset information; the receiving end silicon-based phase modulator is used for carrying out phase modulation on the received light pulse and outputting the light pulse to the receiving end second beam splitter; the receiving end first beam splitter is used for splitting the received coded signal into two light signals, 1% of the light signals are sent to the receiving end first amplitude modulator, and 99% of the light signals are sent to the receiving end second beam splitter; the first amplitude modulator at the receiving end carries out amplitude modulation on the received optical signal and sends the optical signal to the balanced homodyne detector at the receiving end for realizing real-time shot noise monitoring; the receiving end second beam splitter is used for transmitting the received optical signal to the receiving end homodyne detector; the receiving end homodyne detector and the receiving end balance homodyne detector are both used for homodyne detection.
The first amplitude modulator of the receiving end is used for realizing real-time shot noise monitoring, and particularly, when the first amplitude modulator of the receiving end operates, one of the two extinction ratios is randomly selected for measurement: wherein r 1 corresponds to 0dB, and is used for measuring the regular component of the signal; r 2 corresponds to infinity dB for evaluation of shot noise size.
The receiving end homodyne detector comprises a 50:50 beam splitter, a first photodiode and a second photodiode; two output ends of the 50:50 beam splitter are respectively connected with the first photodiode and the second photodiode; the 50:50 beam splitter is used for equally dividing the received signal into two beams and respectively transmitting the two beams to the first photodiode and the second photodiode; the first photodiode and the second photodiode are used for homodyne detection.
The receiving end laser is a narrow linewidth semiconductor laser.
The invention also provides a distributing method realized by the CVQKD system based on the silicon-based integrated chip, which comprises the following steps:
S1, a light source processing end processes a signal sent by a light source, divides the signal into signal light and pilot signal light, and sends the signal light and pilot signal light to a quantum key sending end;
S2, the quantum key transmitting end carries out modulation coding on the signal light, carries out frequency shift processing on the pilot signal light, and transmits the signal light to the quantum key receiving end through an optical fiber channel after coupling;
S3, the quantum key receiving end processes the optical signal output by the optical fiber channel, and meanwhile, the local oscillation light generated locally by the receiving end is processed and then homodyne detection and shot noise size monitoring are carried out; and finishing signal distribution.
In step S2, two different driving voltages are set for the first amplitude modulator at the transmitting end, the first driving voltage of the first amplitude modulator at the transmitting end makes the amplitude generated by the first amplitude modulator at the transmitting end be in rayleigh distribution, and the second driving voltage of the first amplitude modulator at the transmitting end makes the first amplitude modulator at the transmitting end reach maximum light transmission; adjusting working parameters of the second amplitude modulator of the transmitting end to enable the second amplitude modulator of the transmitting end to reach maximum light transmission;
Simultaneously, two different driving voltages are set for the silicon-based phase shifter at the transmitting end, the first driving voltage of the silicon-based phase shifter at the transmitting end enables the silicon-based phase shifter at the transmitting end to generate phase values uniformly distributed in a 0-2 pi interval, the number of the phase values is 2 n, and n is the number of bits of analog-digital conversion; the second driving voltage of the silicon-based phase shifter at the transmitting end enables the silicon-based phase shifter at the transmitting end to generate phase values uniformly distributed in a 0-2 pi interval, wherein the number of the phase values is m, and m is the coding number of a phase space;
When the amplitude generated by the first amplitude modulator at the transmitting end is in Rayleigh distribution, the second amplitude modulator at the transmitting end reaches maximum light transmission, and the silicon-based phase shifter at the transmitting end generates 2 n phase values uniformly distributed in 0-2 pi intervals, the system is Gaussian modulation;
When the first amplitude modulator at the transmitting end reaches the maximum light transmission, the second amplitude modulator at the transmitting end reaches the maximum light transmission, and the silicon-based phase shifter at the transmitting end generates m phase values uniformly distributed in 0-2 pi intervals, the system is discrete modulation.
The CVQKD system and the distribution method based on the silicon-based integrated chip solve the compatibility problem among various different continuous quantum key distribution protocols by adopting the unit architecture with adjustable protocols, and can meet the requirements of the various different continuous quantum key distribution protocols; the local oscillation light for detection is generated at the receiving end, so that calibration attack can be avoided; finally, the system has high integration level, good stability and flexible functions, and provides new possibility for the low-cost and simple quantum network.
Drawings
FIG. 1 is a functional block diagram of the system of the present invention.
Fig. 2 is a functional block diagram of a light source processing end of the present invention.
Fig. 3 is a functional block diagram of a quantum key transmitting end of the present invention.
Fig. 4 is a functional block diagram of a quantum key receiving terminal according to the present invention.
Fig. 5 is a flow chart of the distribution method of the present invention.
Detailed Description
A functional block diagram of the system of the present invention is shown in fig. 1: the CVQKD system based on the silicon-based integrated chip comprises a light source processing end, a quantum key sending end, an optical fiber channel and a quantum key receiving end; the light source processing end, the quantum key sending end, the optical fiber channel and the quantum key receiving end are sequentially connected in series; the light source processing end is used for generating signal light and transmitting the signal light to the quantum key sending end; the quantum key sending end is used for receiving the signal light, processing the signal light and sending the processed signal light to the quantum key receiving end through the optical fiber channel; the quantum key receiving terminal is used for receiving the optical signals and carrying out subsequent processing, so that data receiving is completed.
Fig. 2 is a functional block diagram of a light source processing end according to the present invention: the light source processing end comprises a processing end laser, a processing end ultra-stable resonant cavity, a processing end first amplitude modulator and a processing end first polarization beam splitter; the processing end laser, the processing end ultra-stable resonant cavity, the processing end first amplitude modulator and the processing end first polarization beam splitter are sequentially connected in series; the processing end laser is used for generating continuous light wave signals and inputting the continuous light wave signals into the processing end ultra-stable resonant cavity; the processing end ultra-stable resonant cavity is used for outputting a feedback signal to the processing end laser, ensuring that the processing end laser generates coherent light with narrow linewidth and no phase noise, and transmitting the coherent light to the processing end first amplitude modulator; the processing end first amplitude modulator is used for weakening amplitude noise of received coherent light and transmitting continuous light waves after noise suppression to the processing end first polarization beam splitter; the processing end first polarization beam splitter is used for dividing received continuous light waves into two beams, wherein 1% of the beams are signal light, and 99% of the beams are pilot signal light; and transmits the signal light and the pilot signal light to the quantum key transmitting terminal. In particular, the processing end laser may be a narrow linewidth semiconductor laser.
Fig. 3 is a functional block diagram of a quantum key sending end according to the present invention: the quantum key transmitting end comprises a transmitting end first isolator, a transmitting end first adjustable optical attenuator, a transmitting end second adjustable optical attenuator, a transmitting end first beam splitter, a transmitting end first amplitude modulator, a transmitting end second beam splitter, a transmitting end silicon-based phase shifter, a transmitting end third adjustable optical attenuator, a transmitting end polarization beam combiner, a transmitting end two-dimensional grating coupler, a transmitting end acousto-optic modulator and a transmitting end second isolator; the output end of the first isolator of the transmitting end is connected with the input ends of the first adjustable optical attenuator of the transmitting end and the second adjustable optical attenuator of the transmitting end; the output end of the first adjustable optical attenuator at the transmitting end is connected with the input end of the first beam splitter at the transmitting end; the output end of the first beam splitter of the transmitting end is simultaneously connected with the input ends of the first amplitude modulator of the transmitting end and the second amplitude modulator of the transmitting end; the output end of the first amplitude modulator at the transmitting end and the output end of the second amplitude modulator at the transmitting end are simultaneously connected with the input end of the second beam splitter at the transmitting end; the output end of the second beam splitter at the transmitting end is sequentially connected with a silicon-based phase shifter at the transmitting end, a third adjustable optical attenuator at the transmitting end, a polarization beam combiner at the transmitting end and a two-dimensional grating coupler at the transmitting end in series; the transmitting end second adjustable optical attenuator, the transmitting end acousto-optic modulator and the transmitting end second isolator are sequentially connected in series; the output end of the second isolator of the transmitting end is connected with the input end of the polarization beam combiner of the transmitting end; the first isolator of the transmitting end is used for isolating input signals, transmitting the input signal light to the first adjustable optical attenuator of the transmitting end, and transmitting the input pilot signal light to the second adjustable optical attenuator of the transmitting end; the first adjustable optical attenuator at the transmitting end is used for adjusting the intensity of the received signal light and inputting the adjusted signal light to the first beam splitter at the transmitting end; the second adjustable optical attenuator at the transmitting end is used for adjusting the intensity of the received pilot signal light and inputting the adjusted pilot signal light to the acousto-optic modulator at the transmitting end; the first beam splitter at the transmitting end is used for splitting the received signal light and outputting the split signals to the first amplitude modulator at the transmitting end and the second amplitude modulator at the transmitting end at the same time; the transmitting end first amplitude modulator is used for carrying out amplitude modulation on the received signal and transmitting the modulated signal to the transmitting end second beam splitter; the transmitting end second amplitude modulator is used for carrying out amplitude modulation on the received signal and transmitting the modulated signal to the transmitting end second beam splitter; the second beam splitter at the transmitting end is used for combining the received signals and transmitting the combined signals to the silicon-based phase shifter at the transmitting end; the first beam splitter at the transmitting end, the first amplitude modulator at the transmitting end, the second amplitude modulator at the transmitting end and the second beam splitter at the transmitting end form an equal-arm Mach-Zehnder modulator; the transmitting end silicon-based phase shifter is used for enhancing the phase factor of the received optical signal and outputting the optical signal to the transmitting end third adjustable optical attenuator; the third adjustable optical attenuator at the transmitting end is used for adjusting the intensity of the received optical signal so as to maximize the key rate and transmitting the adjusted optical signal to the polarization beam combiner at the transmitting end; the transmitting end acousto-optic modulator is used for performing frequency up-shifting on the received pilot signal light and transmitting the up-shifted signal to the transmitting end second isolator; the second isolator at the transmitting end is used for isolating the received signals and transmitting the signals to the polarization beam combiner at the transmitting end; the transmitting end polarization beam combiner is used for combining the received two paths of optical signals and outputting the two paths of optical signals to the transmitting end two-dimensional grating coupler; the transmitting end two-dimensional grating coupler is used for coupling the received optical signals into the waveguide and transmitting the optical signals to the quantum key receiving end through the optical fiber channel. In the specific implementation, the transmitting-end acousto-optic modulator is an upward-shifting acousto-optic modulator; and the light source processing end except the processing end laser, the quantum key sending end except the sending end acousto-optic modulator and the quantum key receiving end are integrated on the same silicon-based photon chip by adopting a silicon photon integration technology.
Fig. 4 is a functional block diagram of a quantum key receiving end according to the present invention: the quantum key receiving end comprises a receiving end polarization controller, a receiving end filter, a receiving end two-dimensional grating coupler, a receiving end first polarization beam splitter, a receiving end isolator, a receiving end acousto-optic modulator, a receiving end 90-degree mixer, a receiving end first beam splitter, a receiving end first amplitude modulator, a receiving end second beam splitter, a receiving end laser, a receiving end second amplitude modulator, a receiving end third beam splitter, a receiving end silicon-based phase modulator, a receiving end homodyne detector and a receiving end balanced homodyne detector; the receiving end polarization controller, the receiving end filter, the receiving end two-dimensional grating coupler and the receiving end first polarization beam splitter are sequentially connected in series; the first output end of the receiving end first polarization beam splitter is connected with the input end of the receiving end first beam splitter, and the second output end of the receiving end first polarization beam splitter is connected with the input end of the receiving end isolator; the first output end of the first beam splitter of the receiving end is connected with the output end of the first amplitude modulator of the receiving end, and the output end of the first amplitude modulator of the receiving end is connected with the balanced homodyne detector of the receiving end; the second output end of the receiving end first beam splitter is connected with the first input end of the receiving end second beam splitter; the output end of the receiving end isolator is connected with the input end of the receiving end acousto-optic modulator, and the output end of the receiving end acousto-optic modulator is connected with the first input end of the receiving end 90-degree mixer; the receiving end laser, the receiving end second amplitude modulator and the receiving end third beam splitter are sequentially connected in series; the first output end of the receiving end third beam splitter is connected with the input end of the receiving end silicon-based phase modulator, and the output end of the receiving end silicon-based phase modulator is connected with the second input end of the receiving end second beam splitter; the second output end of the receiving end third beam splitter is connected with the second input end of the receiving end 90-degree mixer; the output end of the receiving end second beam splitter and the output end of the receiving end 90-degree mixer are both connected with a receiving end homodyne detector; the receiving end polarization controller is used for supplementing deflection of the polarization direction of the coupling light emitted by the optical fiber channel to the received optical signal and sending the supplemented optical signal to the receiving end filter; the receiving end filter is used for filtering the received optical signals and sending the filtered optical signals to the receiving end two-dimensional grating coupler; the receiving end two-dimensional grating coupler is used for coupling the received optical signals into the silicon waveguide and transmitting the optical signals to the receiving end first polarization beam splitter; the receiving end first polarization beam splitter is used for carrying out polarization separation on the received optical signals to obtain pilot signals and coded signals; the pilot signal is sent to the isolator of the receiving end, and the coded signal is sent to the first beam splitter of the receiving end; the receiving end isolator is used for isolating the received pilot signals and then sending the pilot signals to the receiving end acousto-optic modulator; the receiving end acousto-optic modulator is used for performing frequency movement on the received signal and transmitting the moved signal to the 90-degree mixer at the receiving end; the receiving end laser is used for generating local oscillation light and outputting the local oscillation light to the receiving end second amplitude modulator; the second amplitude modulator at the receiving end is used for carrying out amplitude modulation on the received local oscillation light, generating optical pulses and sending the optical pulses to the third beam splitter at the receiving end; the receiving end third beam splitter is used for splitting the received light pulse into two beams, 1% of the light pulse is input to the receiving end 90-degree mixer, and 99% of the light pulse is input to the receiving end silicon-based phase modulator; the 90-degree mixer at the receiving end is used for mixing the received optical signals and outputting the mixed signals to the homodyne detector at the receiving end to provide phase offset information; the receiving end silicon-based phase modulator is used for carrying out phase modulation on the received light pulse and outputting the light pulse to the receiving end second beam splitter; the receiving end first beam splitter is used for splitting the received coded signal into two light signals, 1% of the light signals are sent to the receiving end first amplitude modulator, and 99% of the light signals are sent to the receiving end second beam splitter; the first amplitude modulator at the receiving end carries out amplitude modulation on the received optical signal and sends the optical signal to the balanced homodyne detector at the receiving end for realizing real-time shot noise monitoring; the receiving end second beam splitter is used for transmitting the received optical signal to the receiving end homodyne detector; the receiving end homodyne detector and the receiving end balance homodyne detector are both used for homodyne detection.
In specific implementation, the first amplitude modulator at the receiving end is used for realizing real-time shot noise monitoring, specifically, when the first amplitude modulator at the receiving end operates, one of the two extinction ratios is randomly selected for measurement: wherein r 1 corresponds to 0dB, and is used for measuring the regular component of the signal; r 2 corresponds to infinity dB for evaluation of shot noise size. The receiving end homodyne detector comprises a 50:50 beam splitter, a first photodiode and a second photodiode; two output ends of the 50:50 beam splitter are respectively connected with the first photodiode and the second photodiode; the 50:50 beam splitter is used for equally dividing the received signal into two beams and respectively transmitting the two beams to the first photodiode and the second photodiode; the first photodiode and the second photodiode are used for homodyne detection. The receiving end laser is a narrow linewidth semiconductor laser.
Fig. 5 is a method flow chart of the distribution method of the present invention: the distribution method realized by the CVQKD system based on the silicon-based integrated chip comprises the following steps:
S1, a light source processing end processes a signal sent by a light source, divides the signal into signal light and pilot signal light, and sends the signal light and pilot signal light to a quantum key sending end;
S2, the quantum key transmitting end carries out modulation coding on the signal light, carries out frequency shift processing on the pilot signal light, and transmits the signal light to the quantum key receiving end through an optical fiber channel after coupling;
S3, the quantum key receiving end processes the optical signal output by the optical fiber channel, and meanwhile, the local oscillation light generated locally by the receiving end is processed and then homodyne detection and shot noise size monitoring are carried out; and finishing signal distribution.
In step S2, two different driving voltages are set for the first amplitude modulator at the transmitting end, the first driving voltage of the first amplitude modulator at the transmitting end makes the amplitude generated by the first amplitude modulator at the transmitting end be in rayleigh distribution, and the second driving voltage of the first amplitude modulator at the transmitting end makes the first amplitude modulator at the transmitting end reach maximum light transmission; adjusting working parameters of the second amplitude modulator of the transmitting end to enable the second amplitude modulator of the transmitting end to reach maximum light transmission;
Simultaneously, two different driving voltages are set for the silicon-based phase shifter at the transmitting end, the first driving voltage of the silicon-based phase shifter at the transmitting end enables the silicon-based phase shifter at the transmitting end to generate phase values uniformly distributed in a 0-2 pi interval, the number of the phase values is 2 n, and n is the number of bits of analog-digital conversion; the second driving voltage of the silicon-based phase shifter at the transmitting end enables the silicon-based phase shifter at the transmitting end to generate phase values uniformly distributed in a 0-2 pi interval, wherein the number of the phase values is m, and m is the coding number of a phase space;
When the amplitude generated by the first amplitude modulator at the transmitting end is in Rayleigh distribution, the second amplitude modulator at the transmitting end reaches maximum light transmission, and the silicon-based phase shifter at the transmitting end generates 2 n phase values uniformly distributed in 0-2 pi intervals, the system is Gaussian modulation;
When the first amplitude modulator at the transmitting end reaches the maximum light transmission, the second amplitude modulator at the transmitting end reaches the maximum light transmission, and the silicon-based phase shifter at the transmitting end generates m phase values uniformly distributed in 0-2 pi intervals, the system is discrete modulation.
The system of the present invention is further described in the following in one embodiment:
A laser (preferably a tuneable laser model TSL-510) generates a continuous light wave at 1550nm, which after use of an ultra stable cavity and amplitude modulator, produces a coherent light source, which is passed through a beam splitter at 1:99 are divided into two beams, wherein 1% of the two beams are signal light, 99% of the other beams are pilot signal light, the signal light is output to a first adjustable attenuator at a transmitting end, and the pilot signal light is output to a second adjustable attenuator at the transmitting end;
Providing a driving voltage for a first amplitude modulator at a transmitting end, wherein the driving voltage enables the amplitude of the driving voltage to be in Rayleigh distribution; adjusting a second amplitude modulator at the transmitting end to enable the second amplitude modulator to reach the maximum light transmission of the static voltage; providing a drive voltage for the silicon-based phase shifter at the transmitting end, so that the drive voltage generates phases uniformly distributed in a 0-2 pi interval, and performing phase modulation; thus, signal light obeying a Gaussian distribution with a mean value of 0 and a variance of VA can be obtained, and the quantum state is as follows: x A+ipA > where x A and p A are random numbers, obeying gaussian distribution.
In the pilot signal light path, modulating the frequency by an upward moving acousto-optic modulator, and upward moving the frequency;
the transmitting end polarization beam combiner is used for outputting the light beams from the transmitting end second isolator and the transmitting end third adjustable optical attenuator; specifically, the transmitting-end polarization beam combiner receives the signal light from the third adjustable attenuator at the transmitting end and transmits the signal light to the two-dimensional grating coupler at the transmitting end without processing the signal light; the transmitting end polarization beam combiner receives pilot signal light from the second isolator of the transmitting end, rotates 90 degrees in polarization direction and then transmits the pilot signal light to the two-dimensional grating coupler of the transmitting end; the sending end two-dimensional grating coupler is used for coupling signal light into the waveguide and then transmitting the signal light to the quantum key receiving end through the optical fiber channel.
At a receiving end, a receiving party firstly compensates deflection of a signal light polarization direction in a fiber channel through a receiving end polarization controller, then filters light output by the receiving end polarization controller through a receiving end filter, and then couples the signal light into a silicon waveguide through a receiving end two-dimensional grating coupler; the receiving end first polarization beam splitter is used for carrying out polarization separation on the pilot frequency optical signal and the coded optical signal; specifically, the first polarization beam splitter at the receiving end rotates the polarization direction of light by 90 degrees and then transmits the light to the isolator, and the acousto-optic modulator downwards shifts the frequency of the pilot frequency light signal;
The receiver's laser generates local oscillation light, (preferably the tunable laser with model TSL-510) to generate 1550nm continuous light wave, the receiver generates required light pulse through the second amplitude modulator, the local oscillation light passes through the third beam splitter of the receiver and then uses 1:99 are divided into two beams, wherein 1% of one beam of light and the processed pilot frequency light signal enter an optical mixer for mixing, and the mixed output is detected by a homodyne detector to obtain phase offset information. 99% of local oscillation light is subjected to phase modulation through a receiving end silicon-based phase shifter, and sub local oscillation light is output; after the sub local oscillation light interferes with the signal light, the sub local oscillation light is detected by a homodyne detector, and information modulated on regular components X and P by a sender is demodulated.
The first amplitude modulator at the receiving end randomly selects one of two extinction ratios to measure in operation, r1 (preferably 0 dB) is used for measuring regular components of signals, and r2 (preferably infinity dB) is used for evaluating shot noise size, so that real-time shot noise monitoring is realized.
Then, again based on the above system, a specific embodiment of CVQKD is provided that preferably implements discrete modulation based on the above system:
The difference from the CVQKD protocol implementing gaussian modulation is that: in a signal light path, a sender divides signal light into two paths through a first beam splitter at a sending end, and amplitude modulation is carried out through a first amplitude modulator at the sending end and a second amplitude modulator at the sending end respectively; providing the first amplitude modulator at the transmitting end with the maximum light transmission, and adjusting the second amplitude modulator at the transmitting end to the maximum light transmission, wherein the first amplitude modulator at the transmitting end is all static voltage; the phase values which are distributed evenly in the interval of discrete n 0-2 pi are provided for the silicon-based first phase shifter. To this end, the quantum states can be obtained as: x A+ipA where x A and p A are n phase differences on a ring centered on the origin Is defined by the set of coordinates of the points of (a).
Claims (7)
1. The CVQKD system based on the silicon-based integrated chip is characterized by comprising a light source processing end, a quantum key sending end, an optical fiber channel and a quantum key receiving end; the light source processing end, the quantum key sending end, the optical fiber channel and the quantum key receiving end are sequentially connected in series; the light source processing end is used for generating signal light and transmitting the signal light to the quantum key sending end; the quantum key sending end is used for receiving the signal light, processing the signal light and sending the processed signal light to the quantum key receiving end through the optical fiber channel; the quantum key receiving end is used for receiving the optical signals and carrying out subsequent processing so as to finish the data receiving;
The light source processing end comprises a processing end laser, a processing end ultra-stable resonant cavity, a processing end first amplitude modulator and a processing end first polarization beam splitter; the processing end laser, the processing end ultra-stable resonant cavity, the processing end first amplitude modulator and the processing end first polarization beam splitter are sequentially connected in series; the processing end laser is used for generating continuous light wave signals and inputting the continuous light wave signals into the processing end ultra-stable resonant cavity; the processing end ultra-stable resonant cavity is used for outputting a feedback signal to the processing end laser, ensuring that the processing end laser generates coherent light with narrow linewidth and no phase noise, and transmitting the coherent light to the processing end first amplitude modulator; the processing end first amplitude modulator is used for weakening amplitude noise of received coherent light and transmitting continuous light waves after noise suppression to the processing end first polarization beam splitter; the processing end first polarization beam splitter is used for dividing received continuous light waves into two beams, wherein 1% of the beams are signal light, and 99% of the beams are pilot signal light; transmitting the signal light and the pilot signal light to a quantum key transmitting end;
The quantum key transmitting end comprises a transmitting end first isolator, a transmitting end first adjustable optical attenuator, a transmitting end second adjustable optical attenuator, a transmitting end first beam splitter, a transmitting end first amplitude modulator, a transmitting end second beam splitter, a transmitting end silicon-based phase shifter, a transmitting end third adjustable optical attenuator, a transmitting end polarization beam combiner, a transmitting end two-dimensional grating coupler, a transmitting end acousto-optic modulator and a transmitting end second isolator; the output end of the first isolator of the transmitting end is connected with the input ends of the first adjustable optical attenuator of the transmitting end and the second adjustable optical attenuator of the transmitting end; the output end of the first adjustable optical attenuator at the transmitting end is connected with the input end of the first beam splitter at the transmitting end; the output end of the first beam splitter of the transmitting end is simultaneously connected with the input ends of the first amplitude modulator of the transmitting end and the second amplitude modulator of the transmitting end; the output end of the first amplitude modulator at the transmitting end and the output end of the second amplitude modulator at the transmitting end are simultaneously connected with the input end of the second beam splitter at the transmitting end; the output end of the second beam splitter at the transmitting end is sequentially connected with a silicon-based phase shifter at the transmitting end, a third adjustable optical attenuator at the transmitting end, a polarization beam combiner at the transmitting end and a two-dimensional grating coupler at the transmitting end in series; the transmitting end second adjustable optical attenuator, the transmitting end acousto-optic modulator and the transmitting end second isolator are sequentially connected in series; the output end of the second isolator of the transmitting end is connected with the input end of the polarization beam combiner of the transmitting end; the first isolator of the transmitting end is used for isolating input signals, transmitting the input signal light to the first adjustable optical attenuator of the transmitting end, and transmitting the input pilot signal light to the second adjustable optical attenuator of the transmitting end; the first adjustable optical attenuator at the transmitting end is used for adjusting the intensity of the received signal light and inputting the adjusted signal light to the first beam splitter at the transmitting end; the second adjustable optical attenuator at the transmitting end is used for adjusting the intensity of the received pilot signal light and inputting the adjusted pilot signal light to the acousto-optic modulator at the transmitting end; the first beam splitter at the transmitting end is used for splitting the received signal light and outputting the split signals to the first amplitude modulator at the transmitting end and the second amplitude modulator at the transmitting end at the same time; the transmitting end first amplitude modulator is used for carrying out amplitude modulation on the received signal and transmitting the modulated signal to the transmitting end second beam splitter; the transmitting end second amplitude modulator is used for carrying out amplitude modulation on the received signal and transmitting the modulated signal to the transmitting end second beam splitter; the second beam splitter at the transmitting end is used for combining the received signals and transmitting the combined signals to the silicon-based phase shifter at the transmitting end; the first beam splitter at the transmitting end, the first amplitude modulator at the transmitting end, the second amplitude modulator at the transmitting end and the second beam splitter at the transmitting end form an equal-arm Mach-Zehnder modulator; the transmitting end silicon-based phase shifter is used for enhancing the phase factor of the received optical signal and outputting the optical signal to the transmitting end third adjustable optical attenuator; the third adjustable optical attenuator at the transmitting end is used for adjusting the intensity of the received optical signal so as to maximize the key rate and transmitting the adjusted optical signal to the polarization beam combiner at the transmitting end; the transmitting end acousto-optic modulator is used for performing frequency up-shifting on the received pilot signal light and transmitting the up-shifted signal to the transmitting end second isolator; the second isolator at the transmitting end is used for isolating the received signals and transmitting the signals to the polarization beam combiner at the transmitting end; the transmitting end polarization beam combiner is used for combining the received two paths of optical signals and outputting the two paths of optical signals to the transmitting end two-dimensional grating coupler; the transmitting end two-dimensional grating coupler is used for coupling the received optical signals into the waveguide and transmitting the optical signals to the quantum key receiving end through the optical fiber channel;
the quantum key receiving end comprises a receiving end polarization controller, a receiving end filter, a receiving end two-dimensional grating coupler, a receiving end first polarization beam splitter, a receiving end isolator, a receiving end acousto-optic modulator and a receiving end The device comprises a mixer, a first receiving-end beam splitter, a first receiving-end amplitude modulator, a second receiving-end beam splitter, a receiving-end laser, a second receiving-end amplitude modulator, a third receiving-end beam splitter, a silicon-based receiving-end phase modulator, a homodyne receiving end and a balanced homodyne receiving end detector; the receiving end polarization controller, the receiving end filter, the receiving end two-dimensional grating coupler and the receiving end first polarization beam splitter are sequentially connected in series; the first output end of the receiving end first polarization beam splitter is connected with the input end of the receiving end first beam splitter, and the second output end of the receiving end first polarization beam splitter is connected with the input end of the receiving end isolator; the first output end of the first beam splitter of the receiving end is connected with the output end of the first amplitude modulator of the receiving end, and the output end of the first amplitude modulator of the receiving end is connected with the balanced homodyne detector of the receiving end; the second output end of the receiving end first beam splitter is connected with the first input end of the receiving end second beam splitter; the output end of the receiving end isolator is connected with the input end of the receiving end acousto-optic modulator, and the output end of the receiving end acousto-optic modulator is connected with the first input end of the receiving end 90-degree mixer; the receiving end laser, the receiving end second amplitude modulator and the receiving end third beam splitter are sequentially connected in series; the first output end of the receiving end third beam splitter is connected with the input end of the receiving end silicon-based phase modulator, and the output end of the receiving end silicon-based phase modulator is connected with the second input end of the receiving end second beam splitter; the second output end of the third beam splitter of the receiving end is connected with the receiving end/>A second input of the mixer; output end and receiving end of receiving end second beam splitter/>The output ends of the mixers are connected with the homodyne detector at the receiving end; the receiving end polarization controller is used for supplementing deflection of the polarization direction of the coupling light emitted by the optical fiber channel to the received optical signal and sending the supplemented optical signal to the receiving end filter; the receiving end filter is used for filtering the received optical signals and sending the filtered optical signals to the receiving end two-dimensional grating coupler; the receiving end two-dimensional grating coupler is used for coupling the received optical signals into the silicon waveguide and transmitting the optical signals to the receiving end first polarization beam splitter; the receiving end first polarization beam splitter is used for carrying out polarization separation on the received optical signals to obtain pilot signals and coded signals; the pilot signal is sent to the isolator of the receiving end, and the coded signal is sent to the first beam splitter of the receiving end; the receiving end isolator is used for isolating the received pilot signals and then sending the pilot signals to the receiving end acousto-optic modulator; the receiving end acousto-optic modulator is used for performing frequency movement on the received signal and transmitting the moved signal to the receiving end/>A mixer; the receiving end laser is used for generating local oscillation light and outputting the local oscillation light to the receiving end second amplitude modulator; the second amplitude modulator at the receiving end is used for carrying out amplitude modulation on the received local oscillation light, generating optical pulses and sending the optical pulses to the third beam splitter at the receiving end; the third beam splitter at the receiving end is used for dividing the received light pulse into two beams, and 1% of one beam of light pulse is input into the receiving endThe mixer inputs 99% of a beam of light pulse to the receiving-end silicon-based phase modulator; receiving end/>The mixer is used for mixing the received optical signals and outputting the mixed signals to the homodyne detector at the receiving end to provide phase offset information; the receiving end silicon-based phase modulator is used for carrying out phase modulation on the received light pulse and outputting the light pulse to the receiving end second beam splitter; the receiving end first beam splitter is used for splitting the received coded signal into two light signals, 1% of the light signals are sent to the receiving end first amplitude modulator, and 99% of the light signals are sent to the receiving end second beam splitter; the first amplitude modulator at the receiving end carries out amplitude modulation on the received optical signal and sends the optical signal to the balanced homodyne detector at the receiving end for realizing real-time shot noise monitoring; the receiving end second beam splitter is used for transmitting the received optical signal to the receiving end homodyne detector; the receiving end homodyne detector and the receiving end balance homodyne detector are both used for homodyne detection.
2. The CVQKD system based on a silicon-based integrated chip of claim 1 wherein said transmit-side acousto-optic modulator is an up-shift acousto-optic modulator; the light source processing end except the processing end laser, the quantum key sending end except the sending end acousto-optic modulator and the quantum key receiving end are integrated on the same silicon-based photon chip by adopting a silicon photon integration technology.
3. The CVQKD system based on a silicon-based integrated chip of claim 2, wherein the receiver side first amplitude modulator is configured to implement real-time shot noise monitoring, and specifically, when the receiver side first amplitude modulator is operating, one of two extinction ratios is randomly selected for measurement: wherein,Corresponding to 0dB, for making measurements of the canonical component of the signal; /(I)Corresponding to infinity dB, for performing an evaluation of shot noise size.
4. A CVQKD system based on a silicon-based integrated chip as claimed in claim 3 wherein said receiver homodyne detector includes a 50:50 beam splitter, a first photodiode and a second photodiode; two output ends of the 50:50 beam splitter are respectively connected with the first photodiode and the second photodiode; the 50:50 beam splitter is used for equally dividing the received signal into two beams and respectively transmitting the two beams to the first photodiode and the second photodiode; the first photodiode and the second photodiode are used for homodyne detection.
5. The CVQKD system based on a silicon-based integrated chip of claim 4, wherein said receiver laser is a narrow linewidth semiconductor laser; the processing end laser is a narrow linewidth semiconductor laser.
6. A distribution method implemented by a CVQKD system based on a silicon-based integrated chip as claimed in any one of claims 1 to 5, comprising the steps of:
S1, a light source processing end processes a signal sent by a light source, divides the signal into signal light and pilot signal light, and sends the signal light and pilot signal light to a quantum key sending end;
S2, the quantum key transmitting end modulates and codes the signal light, carries out frequency shift treatment on pilot signal light, and transmits the signal light to the quantum key receiving end through an optical fiber channel after coupling;
S3, the quantum key receiving end processes the optical signal output by the optical fiber channel, and meanwhile, the local oscillation light generated locally by the receiving end is processed and then homodyne detection and shot noise size monitoring are carried out; and finishing signal distribution.
7. The distribution method implemented by a CVQKD system based on a silicon-based integrated chip of claim 6, wherein in step S2, the first amplitude modulator of the transmitting end sets two different driving voltages, the first driving voltage of the transmitting end makes the amplitude generated by the first amplitude modulator of the transmitting end be in rayleigh distribution, and the second driving voltage of the first amplitude modulator of the transmitting end makes the first amplitude modulator of the transmitting end reach maximum light transmission; adjusting working parameters of the second amplitude modulator of the transmitting end to enable the second amplitude modulator of the transmitting end to reach maximum light transmission;
simultaneously, two different driving voltages are set for the transmitting-end silicon-based phase shifter, and the first driving voltage of the transmitting-end silicon-based phase shifter enables the transmitting-end silicon-based phase shifter to generate Phase values uniformly distributed in intervals, and the number of the phase values is/>N is the number of bits of analog-to-digital conversion; the second driving voltage of the transmitting-end silicon-based phase shifter enables the transmitting-end silicon-based phase shifter to generate/>Phase values uniformly distributed in intervals, wherein the number of the phase values is m, and m is the coding number of a phase space;
when the amplitude generated by the first amplitude modulator at the transmitting end is Rayleigh, the second amplitude modulator at the transmitting end reaches the maximum light transmission, and the silicon-based phase shifter at the transmitting end generates Personal/>When the interval is uniformly distributed with phase values, the system is Gaussian modulation;
When the first amplitude modulator at the transmitting end reaches the maximum light transmission, the second amplitude modulator at the transmitting end reaches the maximum light transmission, and the silicon-based phase shifter at the transmitting end generates m When the interval is uniformly distributed with phase values, the system is in discrete modulation.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108696352A (en) * | 2018-05-25 | 2018-10-23 | 中南大学 | The unrelated quantum key distribution system of continuous variable measuring apparatus and its implementation |
| KR102238186B1 (en) * | 2019-12-27 | 2021-04-09 | 한국과학기술원 | CV QKD system using optical interferometer phase lock scheme for optical homodyne detection |
| CN112968768A (en) * | 2021-02-25 | 2021-06-15 | 山西大学 | Method for generating quantum random number in continuous variable quantum key distribution system |
| CN113037473A (en) * | 2021-03-01 | 2021-06-25 | 中南大学 | CVQKD system and method based on silicon photonic integrated chip |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2907260B1 (en) * | 2012-10-15 | 2020-11-25 | Nokia Technologies Oy | Quantum key distribution |
-
2022
- 2022-06-17 CN CN202210691527.8A patent/CN115001679B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108696352A (en) * | 2018-05-25 | 2018-10-23 | 中南大学 | The unrelated quantum key distribution system of continuous variable measuring apparatus and its implementation |
| KR102238186B1 (en) * | 2019-12-27 | 2021-04-09 | 한국과학기술원 | CV QKD system using optical interferometer phase lock scheme for optical homodyne detection |
| CN112968768A (en) * | 2021-02-25 | 2021-06-15 | 山西大学 | Method for generating quantum random number in continuous variable quantum key distribution system |
| CN113037473A (en) * | 2021-03-01 | 2021-06-25 | 中南大学 | CVQKD system and method based on silicon photonic integrated chip |
Non-Patent Citations (3)
| Title |
|---|
| Neural Network-Powered Nonlinear Compensation Framework for High-Speed Continuous Variable Quantum Key Distribution;huang duan等;《 IEEE Photonics Journal》;20220419;第14卷(第3期);全文 * |
| 基于量子催化的离散调制连续变量量子密钥分发;叶炜;郭迎;夏莹;钟海;张欢;丁建枝;胡利云;;物理学报;20201231(第06期);全文 * |
| 实地验证连续变量量子密钥分发网络及相关技术研究;黄端等;《第十七届全国量子光学学术会议报告》;20160805;全文 * |
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