CN115442041A - Method, apparatus, medium, and device for optimizing light source based on interference contrast - Google Patents
Method, apparatus, medium, and device for optimizing light source based on interference contrast Download PDFInfo
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Abstract
The present invention provides a method, an apparatus, a medium, and a device for optimizing a light source based on interference contrast, wherein the method comprises: changing a current value for driving the light source to output the light pulse according to a predetermined step length; performing time-delay scanning on a first single-photon detector and a second single-photon detector which receive light pulses via an unequal arm interferometer to acquire a first single-photon count scanned for the first single-photon detector and a second single-photon count scanned for the second single-photon detector at each current value; deriving the interference contrast of the unequal arm interferometer aiming at each current value based on the acquired first single photon count and the acquired second single photon count; the current value for driving the light source to output the light pulse is locked to the current value corresponding to the maximum value in the interference contrast. The invention can accurately control the output wavelength of the light source so as to maximize the interference contrast of the unequal arm interferometer in the system, thereby improving the code rate of the system.
Description
Technical Field
The invention relates to the technical field of quantum communication, in particular to a method, a device, a medium and equipment for optimizing a light source based on interference contrast.
Background
In a quantum communication system, such as a quantum key distribution system, the output wavelength of a light source used to prepare an optical pulse may vary as the drive current of the light source varies. For example, in the case of temperature stabilization, a current change of 1mA may cause a change of 0.01nm in the output wavelength of the light source; in the case of a temperature change, a temperature change of 1 deg.C may result in a change of 0.1nm in the output wavelength of the light source. The change can cause the interference contrast of the unequal arm interferometer in the system to be reduced, and the code rate of the system is reduced along with the reduction of the interference contrast. Therefore, the interference contrast of the unequal-arm interferometer in the lifting system has a crucial influence on the rate of composition of the lifting system.
Disclosure of Invention
The invention aims to provide a method, a device, a medium and equipment for optimizing a light source based on interference contrast.
According to an aspect of the present invention, there is provided a method of optimizing a light source based on interference contrast, the method comprising: changing the current value for driving the light source to output the light pulses according to a first predetermined step; performing time-lapse scanning on a first single-photon detector and a second single-photon detector that receive optical pulses via an unequal-arm interferometer to obtain a first single-photon count scanned for the first single-photon detector and a second single-photon count scanned for the second single-photon detector at respective current values for driving the light source to output optical pulses; deriving a first interference contrast of the unequal arm interferometer for each current value for driving the light source to output the light pulse based on the acquired first single photon count and the acquired second single photon count; locking a current value for driving the light source to output the light pulse to a current value corresponding to a maximum value in the first interference contrast.
According to an embodiment of the invention, the method further comprises: changing the delay position of the gating signal for the single-photon detector according to a second preset step length; performing a time-delay scan on the first single-photon detector and the second single-photon detector again to obtain a third single-photon count scanned for the first single-photon detector and a fourth single-photon count scanned for the second single-photon detector at respective time-delay positions of a gate signal for the single-photon detectors; deriving a second interference contrast of the unequal-arm interferometer for each delay position of a gate signal for the single-photon detector based on the acquired third single-photon count and the acquired fourth single-photon count; locking a delay position of a gating signal for a single photon detector to a delay position corresponding to a maximum in the second interference contrast.
According to an embodiment of the invention, the light source is comprised in a transmitting end of a quantum communication system and the unequal arm interferometer, the first single-photon detector and the second single-photon detector are comprised in a receiving end of the quantum communication system.
According to an embodiment of the present invention, the quantum communication system is a quantum key distribution system based on a COW quantum key distribution protocol, and an optical decoding unit of the quantum key distribution system includes a data detector for detecting optical pulses and a monitoring detector for monitoring coherence between the optical pulses.
According to one embodiment of the invention, the monitoring detector comprises the first single-photon detector and the second single-photon detector.
According to another aspect of the present invention, there is provided an apparatus for optimizing a light source based on interference contrast, the apparatus comprising: a light source stepping unit configured to change a current value for driving the light source to output a light pulse by a first predetermined step; a time-delay scanning unit configured to time-delay scan a first single-photon detector and a second single-photon detector that receive optical pulses via an unequal-arm interferometer to obtain a first single-photon count scanned for the first single-photon detector and a second single-photon count scanned for the second single-photon detector at respective current values for driving the light source to output the optical pulses; an interference calculation unit configured to derive a first interference contrast of the unequal arm interferometer for each current value for driving the light source to output a light pulse based on the acquired first single-photon count and second single-photon count; a light source locking unit configured to lock a current value for driving the light source to output the light pulse to a current value corresponding to a maximum value in the first interference contrast.
According to an embodiment of the invention, the light source stepping unit is further configured to change the delay position of the gating signal for the single-photon detector by a second predetermined step; a time-lapse scanning unit further configured to time-lapse scan the first and second single-photon detectors again to acquire a third single-photon count scanned for the first single-photon detector and a fourth single-photon count scanned for the second single-photon detector at respective time-lapse positions of a gate signal for the single-photon detectors; an interference calculation unit further configured to derive a second interference contrast of the unequal arm interferometer for each delay position of the gate signal for the single photon detector based on the acquired third single photon count and the acquired fourth single photon count; a light source locking unit further configured to lock a delay position of a gating signal for a single photon detector to a delay position corresponding to a maximum value in the second interference contrast.
According to an embodiment of the invention, the light source is comprised in a transmitting end of a quantum communication system and the unequal arm interferometer, the first single-photon detector and the second single-photon detector are comprised in a receiving end of the quantum communication system.
According to an embodiment of the present invention, the quantum communication system is a quantum key distribution system based on a COW quantum key distribution protocol, and an optical decoding unit of the quantum key distribution system includes a data detector for detecting optical pulses and a monitoring detector for monitoring coherence between the optical pulses.
According to one embodiment of the invention, the monitoring detector comprises the first single-photon detector and the second single-photon detector.
According to another aspect of the invention, a computer-readable storage medium is provided, in which a computer program is stored which, when being executed by a processor, carries out the method for optimizing a light source based on interference contrast as described above.
According to another aspect of the present invention, there is provided a computer apparatus comprising: a processor; a memory storing a computer program which, when executed by the processor, implements a method of optimizing a light source based on interference contrast as described above.
The method, the device, the medium and the equipment for optimizing the light source based on the interference contrast not only can search the optimal current value for driving the light source to output light pulses for a system (such as, but not limited to, a quantum key distribution system) so as to accurately control the output wavelength of the light source in the system to maximize the interference contrast of an unequal arm interferometer in the system, but also can help to improve the code yield of the system and the adaptability of the light source in the system to the surrounding environment.
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The above objects and features of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings.
FIG. 1 shows a schematic flow diagram of a method for optimizing a light source based on interference contrast according to an exemplary embodiment of the present invention.
FIG. 2 illustrates another schematic flow diagram of a method for optimizing a light source based on interference contrast according to an exemplary embodiment of the present invention.
Fig. 3 illustrates an exemplary data interaction process for optimizing an optical source based on interference contrast in a quantum communication system based on a COW quantum key distribution protocol according to an exemplary embodiment of the present invention.
Fig. 4 is a block diagram illustrating a schematic structure of an apparatus for optimizing a light source based on interference contrast according to an exemplary embodiment of the present invention.
Detailed Description
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a schematic flow diagram of a method for optimizing a light source based on interference contrast according to an exemplary embodiment of the present invention.
Referring to fig. 1, the method illustrated in fig. 1 may include the following steps.
In step 101, a current value for driving an output light pulse of a light source is varied in a first predetermined step.
In step 102, a first single-photon detector and a second single-photon detector that receive optical pulses via an unequal arm interferometer are time-lapse scanned to obtain a first single-photon count scanned for the first single-photon detector and a second single-photon count scanned for the second single-photon detector at respective current values for driving the light source to output the optical pulses.
In step 103, a first interference contrast of the unequal arm interferometer with respect to each current value for driving the light source to output the light pulse is derived based on the acquired first single photon count and second single photon count.
At step 104, the current value used to drive the light source to output the light pulses is locked to the current value corresponding to the maximum value in the first interference contrast.
In some examples, the light source may be included in a transmitting end of a quantum communication system, and the unequal arm interferometer, the first single-photon detector, and the second single-photon detector may be included in a receiving end of the quantum communication system. This not only allows for finding the optimal current value for driving the output light pulses of the light source for a system such as, but not limited to, a quantum key distribution system to maximize the interference contrast of the unequal arm interferometer in the system by precisely controlling the output wavelength of the light source in the system, but also helps to improve the rate of composition of the system and the adaptability of the light source in the system to the surrounding environment.
In addition, in order to reduce noise in the system and crosstalk between adjacent light pulses, on the basis of the method shown in fig. 1, the delay position of the gate signal for the single-photon detector in the system can be optimized based on the interference contrast, so as to maximize the detection count of the single-photon detector, and further improve the rate of finished products of the system.
Fig. 2 shows another schematic flow diagram of a method for optimizing a light source based on interference contrast according to an exemplary embodiment of the present invention.
Referring to fig. 2, the method shown in fig. 2 may include the following steps.
In step 201 the delay position of the gating signal for the single photon detector is changed in a second predetermined step.
In step 202, the first and second single photon detectors are again time-delayed scanned to obtain a third single photon count scanned for the first single photon detector and a fourth single photon count scanned for the second single photon detector at respective time-delayed positions of the gate signal for the single photon detectors.
In step 203, based on the acquired third single-photon count and fourth single-photon count, a second interference contrast of the unequal-arm interferometer is derived for each delay position of the gate signal for the single-photon detector.
In step 204, the delay position of the gating signal for the single photon detector is locked to the delay position corresponding to the maximum value in the second interference contrast.
In the following, a specific implementation process for optimizing a light source based on interference contrast according to an exemplary embodiment of the present invention is described in further detail by taking a quantum communication system based on a COW quantum key distribution protocol as an example.
Fig. 3 shows an exemplary data interaction process for optimizing a light source based on interference contrast in a quantum communication system based on a COW (Coherent One Way) quantum key distribution protocol according to an exemplary embodiment of the present invention.
Referring to fig. 3, in the quantum communication system shown in fig. 3, a light source Laser and an intensity modulator IM may be included in the transmitting end Alice, and a data detector D for detecting light pulses B And a monitoring detector D for checking coherence between the light pulses M1 And D M2 May be included in the receiving end Bob where a beam splitter may be used to split out a portion of the light pulse to enter the monitoring via an unequal arm interferometer M-Z with a phase shifter PS arranged on its long armDetector D M1 And D M2 While splitting another portion of the light pulse into the data detector D B 。
In the quantum communication system shown in fig. 3, the optical source Laser may randomly emit an optical pulse carrying one of the following three signal states based on the COW quantum key distribution protocol: a bit 0 signal state (logic 0), a bit1 signal state (logic 1), and a decoy signal state (decoy state). In the light pulse sequence emitted by the light source Laser, the interval is
The light pulse can generate coherent interference at the output end of the unequal arm interferometer M-Z, and the coherent interference is carried out on the monitoring detector D M1 And D M2 Performing a time-lapse scan, the interference contrast of the unequal arm interferometer M-Z to the light pulse may be determined based on the following equation (1):
wherein the content of the first and second substances,
representing the interference contrast of the unequal arm interferometer for the light pulse;
representation for monitoring the detector D M1 And the probability of single photon counts scanned;
for monitoring detector D M2 And the probability of single photon counting scanned.
In the quantum communication system shown in fig. 3, the light source can be optimized according to the data interaction process shown in fig. 3.
At S301, the receiving end Bob disables the data detector D B Enabling the monitoring detector D M1 And D M2 And at S302, the transmitting end Alice is notified to enter the optimizing state.
At S303, the transmitting end Alice sends the initial value current of the current for driving the light source Laser to output the light pulse to the receiving end Bob according to the optimization notification.
At S304, the receiving end Bob acquires coarse-grained scanning settings about the light source Laser, the coarse-grained scanning settings including a minimum value currentCoarseMin and a maximum value currentCoarseMax of a coarse-grained scanning range and a coarse-grained scanning step currentCoarseStep, and at S305, notifies the transmitting end Alice to step up the current for driving the light source Laser to output the light pulses based on the initial value current of the current for driving the light source Laser to output the light pulses according to the coarse-grained scanning settings.
In S306, the transmitting end Alice increments the current value for driving the light source Laser to output the light pulse from current + current coarse min to current + current coarse max by a coarse-granularity scanning step current coarse step, and in S307, notifies the receiving end Bob of each increment of the current for driving the light source Laser to output the light pulse.
At S308, the receiving end Bob monitors the detector D for each step-and-increment of the current for driving the light source Laser to output the light pulse for the transmitting end Alice M1 And D M2 Performing a time-lapse scan to calculate an interference contrast visibility of the unequal arm interferometer M-Z for each step increment of a current for driving the light source Laser to output a light pulse according to equation (1), and taking a current value valueCurrent for each step increment and the interference contrast visibility of the unequal arm interferometer M-Z for the current value valueCurrent as vectors<valueCurrent, visibility>Recording into the coarse-grained scan vector list coarse visual availability of the interference contrast for the light source Laser until the current value for driving the light source Laser to output the light pulse reaches current + current coarse max.
At S309, the receiving end Bob finds the current value coarseCurrent in the vector with the maximum interference contrast from the coarse-granularity scan vector list coarsevisibilities for the interference contrast of the light source Laser.
At S310, the receiving end Bob obtains fine-grained scanning settings about the light source Laser, where the fine-grained scanning settings include a minimum currentFineMin and a maximum currentFineMax of a fine-grained scanning range, and a fine-grained scanning step currentFineStep, and at S311, notifies the transmitting end Alice to continue step-up the current for driving the light source Laser to output the light pulse based on the current value coarseCurrent for driving the light source Laser to output the light pulse according to the fine-grained scanning settings.
In S312, the transmitting end Alice increments the current value for driving the light source Laser to output the light pulse from coarcurrent + currentFineMin to coarcurrent + currentFineMax in a step-by-step manner according to the fine-grain scanning step currentFineStep, and in S313, notifies the receiving end Bob of each increment of the current for driving the light source Laser to output the light pulse.
At S314, the receiving end Bob monitors the detector D for each step-and-increment of the current for driving the light source Laser to output the light pulse for the transmitting end Alice M1 And D M2 Performing a time-lapse scan to calculate an interference contrast visibility of the unequal arm interferometer M-Z for each step increment of a current for driving the light source Laser to output a light pulse according to the above formula (1), and taking a current value valueCurrent for each step increment and the interference contrast visibility of the unequal arm interferometer M-Z for the current value valueCurrent as vectors<valueCurrent, visibility>Recording into a fine-grained scan vector list fineVisibility of interference contrast for the light source Laser until the current value for driving the light source Laser to output the light pulse reaches coarseCurrent + currentFineMax.
In S315, the receiving end Bob finds the current value fineCurrent in the vector with the maximum interference contrast from the fine-grained scan vector list fineVisibility for the interference contrast of the light source Laser, and in S316, records the maximum interference contrast tmpvisual corresponding to the current value fineCurrent, and sends the found current value fineCurrent in the vector with the maximum interference contrast as the optimal current value optimalCurrent to the transmitting end Alice.
At S317, the transmitting terminal Alice locks the current value for driving the light source Laser to output the light pulse to the optimal current value optimalCurrent, and at S318, notifies the receiving terminal Bob that the current for driving the light source Laser to output the light pulse has been locked.
In S319, the receiving end Bob obtains the delay scan setting for the single-photon detector according to the lock notification, where the delay scan setting includes a delay scan step delayStep for the single-photon detector, and in S320, performs step-down or step-up on the delay position delay of the gate signal for the single-photon detector according to the delay scan step delayStep. By way of example and not limitation, the delay position delay of the gating signal for the single photon detector may be decremented by a delay scan step delay, and the detector D may be monitored for each incremental decrement of the delay position delay of the gating signal for the single photon detector M1 And D M2 Performing delay scanning to calculate interference contrast visibility of the unequal arm interferometer M-Z for each step decreasing of the delay position delay for the gate signal of the single photon detector according to the formula (1), if the interference contrast visibility is greater than tmpVisity, updating the interference contrast visibility to tmpVisity, and continuing to perform delay decreasing on the delay position delay for the gate signal of the single photon detector according to a delay scanning step length delayStep; if the interference contrast visibility is less than tmpVisibility, the delay position delay of the gate control signal for the single photon detector is increased by a delay scanning step length delayStep in a delayed manner, and the monitoring detector D is monitored for each step increase of the delay position delay of the gate control signal for the single photon detector M1 And D M2 Performing a delay scan to calculate an interference contrast visibilities of the unequal arm interferometer M-Z for each step increment of the delay position delay of the gate signal for the single photon detector according to the formula (1); if the interference contrast ratio visibility is larger than tmpVisability, updating the interference contrast ratio visibility to tmpVisability, and continuing to carry out delay increment on the delay position delay of the gating signal for the single-photon detector according to the delay scanning step delayStep; if the interference contrast visibility is less than tmpVisibility, the delay increment of the delay position delay for the gating signal for the single-photon detector is stopped,and taking the delay position delay of the gating signal for the single photon detector as the monitoring detector D M1 And D M2 And the interference contrast tmpvisual stability at that time is recorded as the optimal interference contrast optimalvisual stability.
It should be understood that although fig. 3 shows an example of optimizing a light source based on interference contrast in a quantum communication system based on a COW quantum key distribution protocol according to an exemplary embodiment of the present invention, the present invention is not limited thereto, and the light source may also be optimized based on interference contrast in a quantum communication system based on other quantum key distribution protocols (such as, but not limited to, BB84 protocol) as needed.
Fig. 4 is a block diagram illustrating a schematic structure of an apparatus for optimizing a light source based on interference contrast according to an exemplary embodiment of the present invention.
Referring to fig. 4, the apparatus shown in fig. 4 may include at least a light source stepping unit 401, a delay scanning unit 402, an interference calculation unit 403, and a light source locking unit 404.
In the apparatus shown in fig. 4, the light source stepping unit 401 may be configured to change the current value for driving the light source to output the light pulse in a first predetermined step; the time-delay scanning unit 402 may be configured to time-delay scan a first single-photon detector and a second single-photon detector that receive light pulses via an unequal-arm interferometer to obtain a first single-photon count scanned for the first single-photon detector and a second single-photon count scanned for the second single-photon detector at respective current values for driving light source to output light pulses; the interference calculation unit 403 may be configured to derive a first interference contrast of the unequal arm interferometer for each current value for driving the light source to output the light pulse, based on the acquired first single-photon count and second single-photon count; the light source locking unit 404 may be configured to lock a current value for driving the light source to output the light pulse to a current value corresponding to a maximum value in the first interference contrast.
In some examples, the light source may be included in a transmitting end of a quantum communication system, and the unequal arm interferometer, the first single-photon detector, and the second single-photon detector may be included in a receiving end of the quantum communication system. This not only allows the system (such as, but not limited to, a quantum key distribution system) to find the optimal current value for driving the light source to output light pulses to maximize the interference contrast of the unequal arm interferometer in the system by precisely controlling the output wavelength of the light source in the system, but also helps to improve the rate of coding of the system and the adaptability of the light source in the system to the surrounding environment.
Furthermore, to reduce noise in the system and crosstalk between adjacent light pulses, in the apparatus shown in fig. 4, the light source stepping unit 401 may be further configured to change the delay position of the gating signal for the single-photon detector by a second predetermined step; the delayed-scan unit 402 may be further configured to again delay-scan the first and second single-photon detectors to obtain a third single-photon count scanned for the first single-photon detector and a fourth single-photon count scanned for the second single-photon detector at respective delayed positions of the gate signal for the single-photon detectors; the interference calculation unit 403 may be further configured to derive a second interference contrast of the unequal-arm interferometer for each delay position of the gate signal for the single-photon detector based on the acquired third single-photon count and the fourth single-photon count; the light source locking unit 404 may be further configured to lock the time-delayed position of the gating signal for the single-photon detector to a time-delayed position corresponding to a maximum in the second interference contrast. This enables the apparatus shown in fig. 4 to optimize the delay position of the gate control signal for the single-photon detector in the system based on the interference contrast, so as to maximize the detection count of the single-photon detector, and further improve the rate of finished code of the system.
Further, a computer-readable storage medium storing a computer program may also be provided according to exemplary embodiments of the present invention. The computer readable storage medium stores a computer program that, when executed by a processor, causes the processor to perform a method of optimizing a light source based on interference contrast according to an exemplary embodiment of the present invention. The computer readable recording medium is any data storage device that can store data read by a computer system. Examples of the computer-readable recording medium include: read-only memory, random access memory, read-only optical disks, magnetic tapes, floppy disks, optical data storage devices, and carrier waves (such as data transmission through the internet via wired or wireless transmission paths).
Further, a computing device may also be provided according to an exemplary embodiment of the invention. The computing device includes a processor and a memory. The memory is for storing a computer program. The computer program is executed by a processor causing the processor to perform a method of optimizing a light source based on interference contrast according to an exemplary embodiment of the present invention.
While the present application has been shown and described with reference to preferred embodiments, it will be understood by those skilled in the art that various changes and modifications may be made to these embodiments without departing from the spirit and scope of the present application as defined by the following claims.
Claims (12)
1. A method for optimizing a light source based on interference contrast, comprising:
changing the current value for driving the light source to output the light pulses according to a first predetermined step;
performing time-lapse scanning on a first single-photon detector and a second single-photon detector that receive optical pulses via an unequal-arm interferometer to obtain a first single-photon count scanned for the first single-photon detector and a second single-photon count scanned for the second single-photon detector at respective current values for driving the light source to output optical pulses;
deriving a first interference contrast of the unequal arm interferometer for each current value for driving the light source to output the light pulse based on the acquired first single photon count and the acquired second single photon count;
locking a current value for driving the light source to output the light pulses to a current value corresponding to a maximum value in the first interference contrast.
2. The method of claim 1, further comprising:
changing the delay position of the gating signal for the single-photon detector according to a second preset step length;
performing a time-delay scan on the first single-photon detector and the second single-photon detector again to obtain a third single-photon count scanned for the first single-photon detector and a fourth single-photon count scanned for the second single-photon detector at respective time-delay positions of a gate signal for the single-photon detectors;
deriving a second interference contrast of the unequal arm interferometer for each delay position of a gating signal for the single photon detector based on the obtained third single photon count and the fourth single photon count;
locking a delay position of a gating signal for a single photon detector to a delay position corresponding to a maximum in the second interference contrast.
3. The method of claim 2 wherein the light source is included in a transmitting end of a quantum communication system and the unequal arm interferometer, the first single-photon detector and the second single-photon detector are included in a receiving end of the quantum communication system.
4. The method according to claim 3, wherein the quantum communication system is a quantum key distribution system based on a COW quantum key distribution protocol, and a receiving end of the quantum key distribution system comprises a data detector for detecting optical pulses and a monitoring detector for monitoring coherence between the optical pulses.
5. The method of claim 4 wherein said monitoring detector comprises said first single-photon detector and said second single-photon detector.
6. An apparatus for optimizing a light source based on interference contrast, comprising:
a light source stepping unit configured to change a current value for driving the light source to output a light pulse by a first predetermined step;
a time-lapse scanning unit configured to time-lapse scan a first single-photon detector and a second single-photon detector that receive optical pulses via an unequal arm interferometer to acquire a first single-photon count scanned for the first single-photon detector and a second single-photon count scanned for the second single-photon detector at respective current values for driving the light source to output the optical pulses;
an interference calculation unit configured to derive a first interference contrast of the unequal arm interferometer for each current value for driving the light source to output a light pulse based on the acquired first single-photon count and second single-photon count;
a light source locking unit configured to lock a current value for driving the light source to output the light pulse to a current value corresponding to a maximum value in the first interference contrast.
7. The apparatus of claim 6,
a light source stepping unit further configured to change a delay position of a gate signal for the single-photon detector by a second predetermined step;
a time-lapse scanning unit further configured to time-lapse scan the first and second single-photon detectors again to acquire a third single-photon count scanned for the first single-photon detector and a fourth single-photon count scanned for the second single-photon detector at respective time-lapse positions of a gate signal for the single-photon detectors;
an interference calculation unit further configured to derive a second interference contrast of the unequal arm interferometer for each delay position of the gate signal for the single photon detector based on the acquired third single photon count and the acquired fourth single photon count;
a light source locking unit further configured to lock a delay position of a gating signal for a single photon detector to a delay position corresponding to a maximum value in the second interference contrast.
8. The apparatus of claim 7 wherein the light source is included in a transmitting end of a quantum communication system and the unequal arm interferometer, the first single-photon detector, and the second single-photon detector are included in a receiving end of the quantum communication system.
9. The apparatus of claim 8, wherein the quantum communication system is a quantum key distribution system based on a COW quantum key distribution protocol, and an optical decoding unit of the quantum key distribution system comprises a data detector for detecting optical pulses and a monitoring detector for monitoring coherence between the optical pulses.
10. The apparatus of claim 9 wherein said monitoring detector comprises said first single photon detector and said second single photon detector.
11. A computer-readable storage medium having stored thereon a computer program which, when being executed by a processor, carries out the method for optimizing a light source on the basis of interference contrast of any one of claims 1 to 5.
12. A computing device, comprising:
a processor;
memory storing a computer program which, when executed by a processor, implements a method of optimizing a light source based on interference contrast as claimed in any one of claims 1 to 5.
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| CN116192278A (en) * | 2023-03-30 | 2023-05-30 | 国开启科量子技术(北京)有限公司 | Optimizing method, device, medium and equipment for quantum communication system |
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| CN116192278A (en) * | 2023-03-30 | 2023-05-30 | 国开启科量子技术(北京)有限公司 | Optimizing method, device, medium and equipment for quantum communication system |
| CN116192278B (en) * | 2023-03-30 | 2023-07-11 | 国开启科量子技术(北京)有限公司 | Optimizing method, device, medium and equipment for quantum communication system |
| CN116073912B (en) * | 2023-03-30 | 2023-07-11 | 国开启科量子技术(北京)有限公司 | Optimizing method, device, medium and equipment for quantum communication system |
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