Quantum optical signal processing method and device, storage medium and electronic equipment

Abstract

The present disclosure relates to the technical field of computer, in particular to a quantum optical signal processing method and device, a computer readable storage medium and an electronic device. The method comprises: receiving a multiplexed optical signal, and separating the multiplexed optical signal to obtain a first quantum optical signal and a classical optical signal; wherein the first quantum optical signal corresponds to a first signal noise; performing polarization filtering on the first quantum optical signal to obtain a second quantum optical signal; wherein the polarization direction of the polarization filtering is the same as the polarization direction of the first quantum optical signal, the second quantum optical signal corresponds to a second signal noise, and the second signal noise is smaller than the first signal noise; decoding the second quantum optical signal to obtain target information, and negotiating a quantum key according to the target information. Through the technical scheme of the embodiment of the present disclosure, the problem of low security key generation rate in related technologies can be solved.

Description

Technical Field

[0001] This disclosure relates to the field of computer technology, and more specifically, to a quantum optical signal processing method, a quantum optical signal processing device, a computer-readable storage medium, and an electronic device. Background Technology

[0002] Quantum key distribution (QKD) is a secure key exchange method that utilizes the principles of quantum mechanics. It can generate and distribute keys during communication while ensuring key security, and has received widespread attention in recent years, gradually moving from theory to practical application.

[0003] In related technologies, in order to accelerate the practical application of quantum key distribution, quantum optical signals and classical optical signals are usually transmitted together on the same fiber.

[0004] However, during co-fiber transmission, classical optical signals can crosstalk into the quantum key distribution system. The introduced classical noise will greatly increase the bit error rate of the quantum key distribution system, further reducing the key generation rate and the secure key transmission distance.

[0005] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] The purpose of this disclosure is to provide a quantum optical signal processing method, a quantum optical signal processing device, a computer-readable storage medium, and an electronic device, which can solve the problem of low security key generation rate in related technologies.

[0007] Other features and advantages of this disclosure will become apparent from the following detailed description, or may be learned in part from practice of this disclosure.

[0008] According to a first aspect of this disclosure, a quantum optical signal processing method is provided, applied to a receiver, the method comprising: receiving a multiplexed optical signal; separating the multiplexed optical signal to obtain a first quantum optical signal and a classical optical signal; wherein the first quantum optical signal corresponds to a first signal noise; performing polarization filtering on the first quantum optical signal to obtain a second quantum optical signal; wherein the polarization direction of the polarization filter is the same as the polarization direction of the first quantum optical signal, and the second quantum optical signal corresponds to a second signal noise, the second signal noise being less than the first signal noise; decoding the second quantum optical signal to obtain target information; and negotiating a quantum key based on the target information.

[0009] In an exemplary embodiment of this disclosure, based on the aforementioned scheme and applied to the transmitter, the method further includes: transmitting an initial quantum light pulse, performing polarization modulation on the initial quantum light pulse to obtain a quantum light pulse, encoding the quantum light pulse through a preset encoding dimension to obtain a quantum light signal; multiplexing the quantum light signal with a classical light signal to obtain a multiplexed light signal, and transmitting the multiplexed light signal to the receiver.

[0010] In an exemplary embodiment of this disclosure, based on the aforementioned scheme, polarization filtering is performed on the first quantum optical signal to obtain the second quantum optical signal, including: modulating the polarization state of the first quantum optical signal to the same polarization state as the quantum optical signal in the transmitter to obtain an intermediate quantum optical signal; and performing polarization filtering on the intermediate quantum optical signal to obtain the second quantum optical signal.

[0011] In an exemplary embodiment of this disclosure, based on the aforementioned scheme, polarization filtering is performed by a polarization filtering device, which includes a single-photon detector. The count of the single-photon detector is used to indicate the amount of signal noise entering the single-photon detector. The count of the single-photon detector is minimized when the polarization state of the first quantum optical signal is modulated to be the same as that of the quantum optical signal in the transmitter.

[0012] In an exemplary embodiment of this disclosure, based on the aforementioned scheme, the first signal noise and the second signal noise are in-band signal noise introduced by the classical optical signal, and the second signal noise is half of the first signal noise.

[0013] In one exemplary embodiment of this disclosure, based on the foregoing scheme, multiplexing includes wavelength division multiplexing, time division multiplexing, mode division multiplexing, and space division multiplexing.

[0014] In one exemplary embodiment of this disclosure, based on the aforementioned scheme, the first quantum optical signal includes multiple sub-signals with different wavelengths, and the multiple sub-signals are transmitted by time-division multiplexing.

[0015] According to a second aspect of this disclosure, a quantum optical signal processing apparatus is provided, applied to a receiver. The apparatus includes: a multiplexed optical signal receiving module for receiving a multiplexed optical signal and separating the multiplexed optical signal to obtain a first quantum optical signal and a classical optical signal; wherein the first quantum optical signal corresponds to a first signal noise; a quantum optical signal filtering module for performing polarization filtering on the first quantum optical signal to obtain a second quantum optical signal; wherein the polarization direction of the polarization filter is the same as the polarization direction of the first quantum optical signal, and the second quantum optical signal corresponds to a second signal noise, the second signal noise being less than the first signal noise; and a quantum key negotiation module for decoding the second quantum optical signal to obtain target information and negotiating a quantum key based on the target information.

[0016] According to a third aspect of this disclosure, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the quantum optical signal processing method of the first aspect of the above embodiments.

[0017] According to a fourth aspect of this disclosure, an electronic device is provided, comprising:

[0018] One or more processors; and

[0019] A storage device for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the quantum optical signal processing method as described in the first aspect of the above embodiments.

[0020] The technical solutions provided in this disclosure may have the following beneficial effects:

[0021] In one embodiment of the quantum optical signal processing method disclosed herein, a multiplexed optical signal is received, and the multiplexed optical signal is separated to obtain a first quantum optical signal and a classical optical signal. The first quantum optical signal contains a first signal noise. Polarization filtering is applied to the first quantum optical signal to obtain a second quantum optical signal, wherein the polarization direction of the polarization filter is the same as that of the first quantum optical signal. The second quantum optical signal contains a second signal noise, which is less than the first signal noise. The second quantum optical signal is decoded to obtain target information, and a quantum key is negotiated based on the target information. Through the scheme of this disclosure, polarization filtering can filter signal noise in the quantum optical signal, reducing the bit error rate of the quantum key distribution system, thereby improving the key generation rate and secure key transmission distance of the quantum key distribution system.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0024] Figure 1 A flowchart illustrating a quantum optical signal processing method in an exemplary embodiment of this disclosure is shown schematically.

[0025] Figure 2This schematically illustrates a flowchart of a process in an exemplary embodiment of the present disclosure, in which a quantum optical signal is multiplexed with a classical optical signal to obtain a multiplexed optical signal, and the multiplexed optical signal is sent to a receiver.

[0026] Figure 3 This schematically illustrates a flowchart of obtaining a second quantum optical signal by polarization filtering of an intermediate quantum optical signal in an exemplary embodiment of the present disclosure;

[0027] Figure 4 This schematic diagram illustrates a polarization modulation device according to an exemplary embodiment of the present disclosure;

[0028] Figure 5 This schematic diagram illustrates a co-fiber transmission device for classical optical communication and quantum key distribution in an exemplary embodiment of the present disclosure.

[0029] Figure 6 This schematic diagram illustrates the composition of a quantum optical signal processing apparatus according to an exemplary embodiment of the present disclosure;

[0030] Figure 7 The schematic diagram illustrates a structural schematic of a computer system suitable for implementing an electronic device according to exemplary embodiments of the present disclosure. Detailed Implementation

[0031] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that this disclosure will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., may be employed. In other instances, well-known structures, methods, apparatuses, implementations, materials, or operations are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0032] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, or in one or more software-hardened modules, or in different network and / or processor devices and / or microcontroller devices.

[0033] According to the quantum optical signal processing method provided in this exemplary embodiment, a multiplexed optical signal is received, and the multiplexed optical signal is separated to obtain a first quantum optical signal and a classical optical signal. The first quantum optical signal has a first signal noise. The first quantum optical signal is polarized and filtered to obtain a second quantum optical signal. The polarization direction of the polarization filter is the same as the polarization direction of the first quantum optical signal. The second quantum optical signal has a second signal noise, which is less than the first signal noise. The second quantum optical signal is decoded to obtain target information, and a quantum key is negotiated based on the target information.

[0034] like Figure 1 As shown, the quantum optical signal processing method may include the following steps:

[0035] Step S110: Receive the multiplexed optical signal and separate the multiplexed optical signal to obtain a first quantum optical signal and a classical optical signal; wherein, the first quantum optical signal corresponds to a first signal noise;

[0036] Step S120: Polarization filtering is performed on the first quantum optical signal to obtain a second quantum optical signal; wherein, the polarization direction of the polarization filter is the same as the polarization direction of the first quantum optical signal, and the second quantum optical signal has a second signal noise, which is less than the first signal noise;

[0037] Step S130: Decode the second quantum optical signal to obtain target information, and negotiate the quantum key based on the target information.

[0038] In one embodiment of the quantum optical signal processing method disclosed herein, a multiplexed optical signal is received, and the multiplexed optical signal is separated to obtain a first quantum optical signal and a classical optical signal. The first quantum optical signal contains a first signal noise. Polarization filtering is applied to the first quantum optical signal to obtain a second quantum optical signal, wherein the polarization direction of the polarization filter is the same as that of the first quantum optical signal. The second quantum optical signal contains a second signal noise, which is less than the first signal noise. The second quantum optical signal is decoded to obtain target information, and a quantum key is negotiated based on the target information. Through the scheme of this disclosure, polarization filtering can filter signal noise in the quantum optical signal, reducing the bit error rate of the quantum key distribution system, thereby improving the key generation rate and secure key transmission distance of the quantum key distribution system.

[0039] The steps S110 to S130 of the quantum optical signal processing method in this exemplary embodiment will now be described in more detail with reference to the accompanying drawings and embodiments.

[0040] Step S110: Receive the multiplexed optical signal and separate the multiplexed optical signal to obtain a first quantum optical signal and a classical optical signal; wherein, the first quantum optical signal corresponds to a first signal noise;

[0041] In one exemplary embodiment of this disclosure, a multiplexed optical signal can be received, and the multiplexed optical signal can be separated to obtain a first quantum optical signal and a classical optical signal. Specifically, the multiplexed optical signal can be an optical signal obtained by multiplexing a classical optical signal and a quantum optical signal. Here, the classical optical signal refers to the optical signal used in classical optics, which follows the laws and propagation methods of classical physics; the quantum optical signal refers to the optical signal used in the field of quantum optics, which is governed by the laws of quantum mechanics. Classical optical signals exhibit continuity and wave properties during propagation and processing; while quantum optical signals exhibit the particle characteristics of light, wave-particle duality, and discreteness limited by measurement principles.

[0042] In one exemplary embodiment of this disclosure, a multiplexed optical signal can be separated to obtain a first quantum optical signal and a classical optical signal. Specifically, the classical optical signal and the quantum optical signal can be combined into a multiplexed signal through multiplexing, that is, the multiplexed optical signal can be separated to obtain the first quantum optical signal and the classical optical signal using the separation method corresponding to multiplexing.

[0043] It should be noted that this disclosure does not impose any special limitations on the method of separating multiplexed optical signals.

[0044] In one exemplary embodiment of this disclosure, the first quantum optical signal corresponds to a first signal noise. Specifically, during the transmission of multiplexed optical signals, classical optical signals can crosstalk into the quantum optical signal, thereby introducing classical noise. On the one hand, classical optical signals have higher intensity and their noise floor is tens of orders of magnitude higher than that of quantum optical signals. On the other hand, the nonlinear effects of optical fibers (such as Raman effect, four-wave mixing effect, etc.) make the introduced classical optical noise have a significant impact on the quantum optical signal.

[0045] It should be noted that this disclosure does not specifically limit the cause of the first signal noise.

[0046] Furthermore, when separating the multiplexed optical signal to obtain the first quantum optical signal and the classical optical signal, out-of-band noise can be filtered out by frequency domain filtering.

[0047] The scheme disclosed herein can be used to filter in-band signal noise introduced by classical signals in quantum optical signals.

[0048] Step S120: Polarization filtering is performed on the first quantum optical signal to obtain the second quantum optical signal;

[0049] In one exemplary embodiment of this disclosure, after obtaining the first quantum optical signal through the above steps, polarization filtering can be performed on the first quantum optical signal to obtain a second quantum optical signal. The polarization direction of the polarization filter is the same as the polarization direction of the first quantum optical signal, and the second quantum optical signal corresponds to a second signal noise, which is less than the first signal noise. Specifically, after receiving the first quantum optical signal, polarization filtering can be performed on the first quantum optical signal.

[0050] In one example embodiment of this disclosure, the polarization direction of the polarization filter is the same as the polarization direction of the first quantum optical signal, which may include the polarization direction of the polarization filter being the same as the polarization direction of the quantum optical signal in the transmitter.

[0051] Specifically, since the polarization direction of the polarization filter is the same as the polarization direction of the first quantum optical signal, and the signal noise in the first quantum optical signal maintains its original polarization state, when the first quantum optical signal is polarized and filtered, the first quantum optical signal can pass through normally, while the corresponding part of the signal noise cannot pass through normally, thus achieving the effect of filtering the corresponding part of the signal noise of the first quantum optical signal. Therefore, the second signal noise corresponding to the second quantum optical signal obtained after polarization filtering is less than the first signal noise corresponding to the first quantum optical signal.

[0052] It should be noted that this disclosure does not impose any special limitations on the specific method of obtaining the second quantum optical signal by polarization filtering of the first quantum optical signal.

[0053] Furthermore, the first quantum optical signal can be controlled to enter the polarization beam splitter to perform polarization filtering on the first quantum optical signal and obtain the second quantum optical signal.

[0054] A polarizing beamsplitter is an optical element used to split incident light into two output beams according to their polarization direction. Polarizing beamsplitters are typically composed of a special optical crystal or coating with different refractive indices and absorption properties, resulting in different transmission characteristics for light with different polarization directions. When incident light enters along one axis of the polarizing beamsplitter with a certain polarization direction (i.e., the light passes along that axis), forming a transmitted beam, while a small portion is reflected in the opposite direction, forming a reflected beam. Conversely, when incident light enters with a polarization direction perpendicular to the first axis, the light behaves in the opposite way: most of the light is reflected, forming a reflected beam, while a small portion is transmitted along the second axis, forming a transmitted beam.

[0055] Step S130: Decode the second quantum optical signal to obtain target information, and negotiate the quantum key based on the target information.

[0056] In one exemplary embodiment of this disclosure, when the second quantum optical signal is obtained through the above steps, the second quantum optical signal can be decoded to obtain target information. Specifically, in the sending end, the quantum optical pulse can be encoded according to a preset encoding dimension to obtain a quantum optical signal, and the multiplexed optical signal obtained by multiplexing the quantum optical signal and the classical optical signal is sent to the receiving end. In the receiving end, the second quantum optical signal can be decoded using a preset decoding method corresponding to the preset encoding dimension to obtain the target information.

[0057] It should be noted that this disclosure does not impose any special limitations on the specific method of decoding the second quantum optical signal to obtain the target information.

[0058] In one exemplary embodiment of this disclosure, when the target information is obtained through the above steps, a quantum key can be negotiated based on the target information. Specifically, after the receiver obtains the target information, the sender and receiver can compare and correct the target information through a publicly available classical channel to generate a shared key.

[0059] In one exemplary embodiment of this disclosure, during transmission, due to the irreversibility of quantum mechanics and the principles of measurement, any eavesdropping or tampering with the quantum signal will be detected immediately. Therefore, the next step will only proceed once channel security is confirmed.

[0060] Specifically, after the receiver receives the target information, the sender and receiver can exchange the target information through a public classical channel. They use classical computation methods to compare their target information and, according to a pre-agreed protocol, determine the content within the target information used to generate the final key. For example, the sender and receiver can process and extract the target information, and jointly negotiate the keys used for encryption and decryption.

[0061] In this process, error-correcting codes and randomization processes can be used to handle errors and noise introduced during channel transmission.

[0062] It should be noted that this disclosure does not impose any special restrictions on the specific method of negotiating quantum keys based on target information.

[0063] In one exemplary embodiment of this disclosure, an initial quantum light pulse can be emitted, polarization modulation can be applied to the initial quantum light pulse to obtain a quantum light pulse, the quantum light pulse can be encoded using a preset encoding dimension to obtain a quantum light signal, the quantum light signal can be multiplexed with a classical light signal to obtain a multiplexed light signal, and the multiplexed light signal can be transmitted to a receiver. (Refer to...) Figure 2 As shown, multiplexing a quantum optical signal with a classical optical signal to obtain a multiplexed optical signal, and then transmitting the multiplexed optical signal to the receiver, may include the following steps S210 to S220:

[0064] Step S210: Receive an initial quantum light pulse, perform polarization modulation on the initial quantum light pulse to obtain a quantum light pulse, and encode the quantum light pulse through a preset encoding dimension to obtain a quantum light signal;

[0065] In one exemplary embodiment of this disclosure, an initial quantum light pulse can be emitted, and the initial quantum light pulse can be polarized to obtain a quantum light pulse. Specifically, the initial quantum light pulse can be emitted by a laser, and a polarization modulation device can be set in the laser to obtain the quantum light pulse by polarization modulation of the initial quantum light pulse. Specifically, polarization modulation of the initial quantum light pulse refers to modulation of the initial quantum light pulse in a single polarization direction.

[0066] In one exemplary embodiment of this disclosure, a quantum light pulse can be encoded using a preset encoding dimension to obtain a quantum light signal. Specifically, after obtaining the quantum light pulse, it can be encoded using a preset encoding dimension to obtain a quantum light signal with a specific encoded state. For example, the quantum light pulse can be encoded using phase encoding to obtain a quantum light signal loaded with phase information.

[0067] It should be noted that this disclosure does not impose any special limitations on the specific method of encoding quantum light pulses.

[0068] Step S220: The quantum optical signal and the classical optical signal are multiplexed to obtain a multiplexed optical signal, and the multiplexed optical signal is sent to the receiver.

[0069] In one exemplary embodiment of this disclosure, after obtaining the quantum optical signal through the above steps, the quantum optical signal and the classical optical signal can be multiplexed to obtain a multiplexed optical signal. Specifically, multiplexing the quantum optical signal and the classical optical signal means simultaneously transmitting multiple different optical signals through the same optical fiber or optical transmission system to form a multiplexed optical signal, and then sending the obtained multiplexed optical signal to the receiver. After receiving the multiplexed optical signal, the receiver can use the separation method corresponding to the multiplexing to decompose the multiplexed optical signal into a quantum optical signal and a classical optical signal.

[0070] For example, quantum optical signals and classical optical signals can be multiplexed using optical wavelength division multiplexers, optical mode division multiplexers, and multi-core fiber fan-in / fan-out devices. These devices can combine different optical signals into the same optical fiber.

[0071] In one example embodiment of this disclosure, multiplexing includes wavelength division multiplexing, time division multiplexing, mode division multiplexing, and space division multiplexing.

[0072] It should be noted that this disclosure does not impose any special limitations on the specific method of multiplexing quantum optical signals with classical optical signals to obtain multiplexed optical signals.

[0073] Through the above steps S210 to S220, an initial quantum light pulse can be emitted, the initial quantum light pulse can be polarized and modulated to obtain a quantum light pulse, the quantum light pulse can be encoded by a preset encoding dimension to obtain a quantum light signal, the quantum light signal and the classical light signal can be multiplexed to obtain a multiplexed light signal, and the multiplexed light signal can be sent to the receiver.

[0074] In one exemplary embodiment of this disclosure, the polarization state of a first quantum optical signal can be modulated to be the same as that of the quantum optical signal in the transmitter to obtain an intermediate quantum optical signal. Polarization filtering of the intermediate quantum optical signal then yields a second quantum optical signal. (Refer to...) Figure 3 As shown, obtaining the second quantum optical signal by polarization filtering of the intermediate quantum optical signal may include the following steps S310 to S320:

[0075] Step S310: Modulate the polarization state of the first quantum optical signal to the same polarization state as the quantum optical signal in the transmitter to obtain the intermediate quantum optical signal;

[0076] In one exemplary embodiment of this disclosure, after obtaining the first quantum optical signal through the above steps, the polarization state of the first quantum optical signal can be modulated to be the same as the polarization state of the quantum optical signal in the transmitter, thus obtaining an intermediate quantum optical signal. Specifically, in the transmitter, the initial quantum optical pulse can be polarized to obtain a quantum optical pulse, and the quantum optical pulse can be encoded through a preset encoding dimension to obtain a quantum optical signal. The quantum optical signal and the classical optical signal are then multiplexed to obtain a multiplexed optical signal, meaning that the quantum optical signal in the transmitter corresponds to a polarization state. Since the polarization state of the quantum optical signal changes during the transmission of the multiplexed optical signal, after the receiver receives the multiplexed optical signal and separates it to obtain the first quantum optical signal, the polarization state of the first quantum optical signal can be adjusted so that the polarization state of the adjusted intermediate quantum optical signal is the same as the polarization state of the quantum optical signal in the transmitter, thereby compensating for the change in polarization state of the quantum optical signal during long-distance transmission.

[0077] It should be noted that this disclosure does not impose any special limitations on the specific method of modulating the polarization state of the first quantum optical signal to be the same as the polarization state of the quantum optical signal in the transmitter.

[0078] Step S320: Polarization filtering is performed on the intermediate quantum optical signal to obtain the second quantum optical signal.

[0079] In one exemplary embodiment of this disclosure, after obtaining the intermediate quantum optical signal through the above steps, the intermediate quantum optical signal can be polarized filtered to obtain the second quantum optical signal. Specifically, after modulating the polarization state of the first quantum optical signal to the same polarization state as the quantum optical signal in the transmitter, the polarization direction of the intermediate quantum optical signal is the same as the polarization direction of the polarization filter and the polarization direction of the quantum optical signal in the transmitter. That is, the intermediate quantum optical signal can pass normally, while the signal noise corresponding to the intermediate quantum optical signal cannot pass normally, thereby achieving the effect of filtering the signal noise corresponding to the intermediate quantum optical signal. Therefore, the second signal noise corresponding to the second quantum optical signal obtained after polarization filtering is less than the first signal noise corresponding to the first quantum optical signal.

[0080] Furthermore, the intermediate quantum optical signal can be controlled to pass through a polarization beam splitter to obtain a second quantum optical signal, wherein the polarization direction of the polarization beam splitter is the polarization direction of the polarization filter.

[0081] Through the aforementioned steps S310-S320, the polarization state of the first quantum optical signal can be modulated to be the same as that of the quantum optical signal in the transmitter, resulting in an intermediate quantum optical signal. Polarization filtering of the intermediate quantum optical signal then yields the second quantum optical signal. This disclosed scheme can compensate for the offset during quantum optical signal transmission, thereby improving the transmission efficiency of the quantum optical signal.

[0082] In one exemplary embodiment of this disclosure, polarization filtering can be performed using a polarization filtering device. Specifically, a second quantum optical signal can be obtained by polarization filtering the first quantum optical signal using this device. The polarization filtering device includes a single-photon detector, and the count of the single-photon detector indicates the amount of signal noise entering the detector. The single-photon detector count is minimized when the polarization state of the first quantum optical signal is modulated to be the same as that of the quantum optical signal in the transmitter. Specifically, if the single-photon detector count is large, it indicates that the polarization state of a portion of the first quantum optical signal is different from that of the quantum optical signal in the transmitter. In this case, the polarization state of the first quantum optical signal can be further modulated so that the polarization state of the modulated intermediate quantum optical signal is the same as that of the quantum optical signal in the transmitter. The single-photon detector count is minimized when the polarization state of the first quantum optical signal is the same as that of the quantum optical signal in the transmitter.

[0083] In one exemplary embodiment of this disclosure, the first signal noise and the second signal noise are in-band signal noise introduced by the classical optical signal, and the second signal noise is half of the first signal noise. Specifically, in-band signal noise refers to the noise components present within the frequency range of the first quantum optical signal. Only in-band signal noise with the same polarization state as the quantum optical signal in the transmitter can be received by the receiver; in-band signal noise with a different polarization state than the quantum optical signal in the transmitter is partially filtered out due to polarization filtering.

[0084] Specifically, Malus's law can be used to filter out the portion of the first quantum optical signal whose polarization state differs from that of the quantum optical signal in the transmitting end. Therefore, half of the in-band signal noise in the first quantum optical signal can be filtered out to obtain the second quantum optical signal, where the second signal noise is less than the first signal noise. Using the scheme disclosed herein, the signal-to-noise ratio of quantum key distribution can be increased by a factor of two, and the bit error rate of the quantum key distribution system can be reduced, thereby improving the key generation rate and secure key transmission distance of the quantum key distribution system.

[0085] In one exemplary embodiment of this disclosure, the first quantum optical signal includes multiple sub-signals with different wavelengths, and these sub-signals are transmitted using time-division multiplexing. Specifically, at the transmitting end, the multiple quantum optical signals (sub-signals) can be multiplexed with a classical optical signal to obtain a multiplexed optical signal. After receiving the multiplexed optical signal, the receiving end can separate the multiplexed optical signal to obtain multiple sub-signals and a classical optical signal. Each sub-signal can then be transmitted using time-division multiplexing.

[0086] Specifically, when multiple sub-signals of different wavelengths are transmitted sequentially using time-division multiplexing, only the sub-signal of the wavelength corresponding to the current time period will be received and processed by the receiving end, while the sub-signals of other wavelengths will be filtered out, thereby filtering out the signal noise brought by the sub-signals of other wavelengths.

[0087] In one exemplary embodiment of this disclosure, such as Figure 4 As shown, a polarization modulation device is provided, which may include an electrically controlled polarization controller, a polarization beamsplitter, and a single-photon detector. The electrically controlled polarization controller modulates the polarization state of a first quantum optical signal to the same polarization state as the quantum optical signal in the transmitter, obtaining an intermediate quantum optical signal. The polarization beamsplitter filters out in-band signal noise in the intermediate quantum optical signal whose polarization state differs from that of the quantum optical signal in the transmitter. The single-photon detector records the number of quantum optical signals entering it; the count is minimized when the polarization state of the first quantum optical signal is modulated to the same polarization state as the quantum optical signal in the transmitter.

[0088] In one exemplary embodiment of this disclosure, such as Figure 5 As shown, a co-fiber transmission device for classical optical communication and quantum key distribution is provided.

[0089] In the transmitter of this device, multiple sub-signals can be transmitted through multiple quantum key distribution transmitters. Different quantum key distribution transmitters use different wavelengths. Each quantum key distribution transmitter can include a laser and a phase encoding device. The laser can be used to transmit an initial quantum light pulse. The initial quantum light pulse is polarized and modulated to obtain a quantum light pulse. The phase encoding device can be used to encode the quantum light pulse to obtain a sub-signal (quantum light signal) loaded with phase information. The multiple sub-signals with phase information obtained are then wavelength divided and multiplexed with a classical optical signal by a wavelength division multiplexer to obtain a multiplexed optical signal. This multiplexed optical signal is then transmitted to the receiver through an optical communication network and an optical amplifier.

[0090] In the receiver of this device, the multiplexed optical signal can be separated into multiple sub-signals (the first quantum optical signal includes multiple sub-signals, which are quantum optical signals) and classical optical signals by a wave demultiplexer. The multiple sub-signals are then transmitted to each quantum key distribution receiver via a delay line. The quantum key distribution receiver includes the aforementioned polarization modulation device, which can filter out some signal noise in the sub-signals to obtain the second quantum optical signal. The second quantum optical signal is then decoded by a phase decoding device to obtain the target information.

[0091] The signal processing solution disclosed herein can be directly integrated with existing OTN (Optical Transport Network) equipment, and can accelerate the large-scale deployment of quantum key distribution systems without customized modifications.

[0092] In one embodiment of the quantum optical signal processing method disclosed herein, a multiplexed optical signal is received, and the multiplexed optical signal is separated to obtain a first quantum optical signal and a classical optical signal. The first quantum optical signal contains a first signal noise. Polarization filtering is applied to the first quantum optical signal to obtain a second quantum optical signal, wherein the polarization direction of the polarization filter is the same as that of the first quantum optical signal. The second quantum optical signal contains a second signal noise, which is less than the first signal noise. The second quantum optical signal is decoded to obtain target information, and a quantum key is negotiated based on the target information. Through the scheme of this disclosure, polarization filtering can filter signal noise in the quantum optical signal, reducing the bit error rate of the quantum key distribution system, thereby improving the key generation rate and secure key transmission distance of the quantum key distribution system.

[0093] It should be noted that the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this disclosure, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Furthermore, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0094] Furthermore, in an exemplary embodiment of this disclosure, a quantum optical signal processing apparatus is also provided. (Refer to...) Figure 6 As shown, a quantum optical signal processing device 600 includes: a multiplexed optical signal receiving module 610, a quantum optical signal filtering module 620, and a quantum key negotiation module 630.

[0095] The system includes a multiplexed optical signal receiving module for receiving multiplexed optical signals and separating them into a first quantum optical signal and a classical optical signal; wherein the first quantum optical signal has a first signal noise; a quantum optical signal filtering module for polarization filtering the first quantum optical signal to obtain a second quantum optical signal; wherein the polarization direction of the polarization filter is the same as the polarization direction of the first quantum optical signal, and the second quantum optical signal has a second signal noise, which is less than the first signal noise; and a quantum key negotiation module for decoding the second quantum optical signal to obtain target information and negotiating a quantum key based on the target information.

[0096] In an exemplary embodiment of this disclosure, based on the aforementioned scheme and applied to the transmitter, the device further includes: an initial quantum light pulse transmitting unit, used to transmit an initial quantum light pulse, to perform polarization modulation on the initial quantum light pulse to obtain a quantum light pulse, and to encode the quantum light pulse through a preset encoding dimension to obtain a quantum light signal; and a multiplexing unit, used to multiplex the quantum light signal and the classical light signal to obtain a multiplexed light signal, and to send the multiplexed light signal to the receiver.

[0097] In an exemplary embodiment of this disclosure, based on the aforementioned scheme, a second quantum optical signal is obtained by polarization filtering of the first quantum optical signal. The apparatus further includes: a polarization state modulation unit, used to modulate the polarization state of the first quantum optical signal to the same polarization state as the quantum optical signal in the transmitter, to obtain an intermediate quantum optical signal; and a second quantum optical signal acquisition unit, used to obtain the second quantum optical signal by polarization filtering of the intermediate quantum optical signal.

[0098] In an exemplary embodiment of this disclosure, based on the aforementioned scheme, polarization filtering is performed by a polarization filtering device, which includes a single-photon detector. The count of the single-photon detector is used to indicate the amount of signal noise entering the single-photon detector. The count of the single-photon detector is minimized when the polarization state of the first quantum optical signal is modulated to be the same as that of the quantum optical signal in the transmitter.

[0099] In an exemplary embodiment of this disclosure, based on the aforementioned scheme, the first signal noise and the second signal noise are in-band signal noise introduced by the classical optical signal, and the second signal noise is half of the first signal noise.

[0100] In one exemplary embodiment of this disclosure, based on the foregoing scheme, multiplexing includes wavelength division multiplexing, time division multiplexing, mode division multiplexing, and space division multiplexing.

[0101] In an exemplary embodiment of this disclosure, based on the aforementioned scheme, the first quantum optical signal includes multiple sub-signals with different wavelengths, and the multiple sub-signals are transmitted by time-division multiplexing.

[0102] Since the functional modules of the quantum optical signal processing device in the example embodiments of this disclosure correspond to the steps of the example embodiments of the quantum optical signal processing method described above, for details not disclosed in the device embodiments of this disclosure, please refer to the embodiments of the quantum optical signal processing method described above.

[0103] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0104] Furthermore, in an exemplary embodiment of this disclosure, an electronic device capable of implementing the above-described quantum optical signal processing method is also provided.

[0105] Those skilled in the art will understand that various aspects of this disclosure can be implemented as a system, method, or program product. Therefore, various aspects of this disclosure can be embodied in the following forms: a completely hardware embodiment, a completely software embodiment (including firmware, microcode, etc.), or an embodiment combining hardware and software aspects, collectively referred to herein as a "circuit," "module," or "system."

[0106] The following reference Figure 7 To describe an electronic device 700 according to such an embodiment of the present disclosure. Figure 7 The electronic device 700 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments disclosed herein.

[0107] like Figure 7As shown, the electronic device 700 is manifested in the form of a general-purpose computing device. The components of the electronic device 700 may include, but are not limited to: at least one processing unit 710, at least one storage unit 720, a bus 730 connecting different system components (including storage unit 720 and processing unit 710), and a display unit 740.

[0108] The storage unit stores program code, which can be executed by the processing unit 710 to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of this disclosure. For example, the processing unit 710 can perform actions such as... Figure 1 In step S110, a multiplexed optical signal is received, and the multiplexed optical signal is separated to obtain a first quantum optical signal and a classical optical signal; wherein, the first quantum optical signal corresponds to a first signal noise; in step S120, the first quantum optical signal is polarized and filtered to obtain a second quantum optical signal; wherein, the polarization direction of the polarization filter is the same as the polarization direction of the first quantum optical signal, and the second quantum optical signal corresponds to a second signal noise, which is less than the first signal noise; in step S130, the second quantum optical signal is decoded to obtain target information, and a quantum key is negotiated based on the target information.

[0109] For example, electronic devices can achieve such Figure 1 The steps shown.

[0110] Storage unit 720 may include a readable medium in the form of a volatile storage unit, such as random access memory (RAM) 721 and / or cache memory 722, and may further include a read-only memory (ROM) 723.

[0111] The storage unit 720 may also include a program / utility 724 having a set (at least one) of program modules 725, including but not limited to: an operating system, one or more application programs, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0112] Bus 730 can represent one or more of several types of bus structures, including a memory cell bus or memory cell controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.

[0113] Electronic device 700 can also communicate with one or more external devices 770 (e.g., keyboard, pointing device, Bluetooth device, etc.), and with one or more devices that enable a user to interact with electronic device 700, and / or with any device that enables electronic device 700 to communicate with one or more other computing devices (e.g., router, modem, etc.). This communication can be performed via input / output (I / O) interface 750. Furthermore, electronic device 700 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via network adapter 760. As shown, network adapter 760 communicates with other modules of electronic device 700 via bus 730. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with electronic device 700, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0114] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, terminal device, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0115] In exemplary embodiments of this disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the methods described above is stored. In some possible embodiments, various aspects of this disclosure may also be implemented as a program product including program code that, when the program product is run on a terminal device, causes the terminal device to perform the steps described in the "Exemplary Methods" section of this specification according to various exemplary embodiments of this disclosure.

[0116] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0117] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0118] Program code for performing the operations of this disclosure can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's computing device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing devices can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0119] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of this disclosure and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0120] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the claims.

Claims

1. A quantum optical signal processing method, characterized in that, The method includes: The sender transmits an initial quantum light pulse, modulates the initial quantum light pulse with a single polarization direction to obtain a quantum light pulse, encodes the quantum light pulse with a preset encoding dimension to obtain a quantum light signal, and multiplexes the quantum light signal with a classical light signal to obtain a multiplexed light signal, which is then transmitted to the receiver. The receiver receives the multiplexed optical signal and uses a separation method corresponding to multiplexing to separate the multiplexed optical signal to obtain a first quantum optical signal and a classical optical signal; wherein, the first quantum optical signal corresponds to a first signal noise; The receiver performs polarization filtering on the first quantum optical signal to obtain a second quantum optical signal; wherein, the polarization direction of the polarization filter is the same as the polarization direction of the quantum optical signal in the transmitter, and the second quantum optical signal corresponds to a second signal noise, which is less than the first signal noise; the first signal noise and the second signal noise are in-band signal noise introduced by the classical optical signal, and the second signal noise is half of the first signal noise; The receiver decodes the second quantum optical signal to obtain target information and negotiates a quantum key based on the target information.

2. The method according to claim 1, characterized in that, The multiplexing includes at least one of wavelength division multiplexing, mode division multiplexing, and space division multiplexing.

3. The method according to claim 1, characterized in that, The step of polarization filtering the first quantum optical signal to obtain the second quantum optical signal includes: The polarization state of the first quantum optical signal is modulated to be the same as that of the quantum optical signal in the transmitter to obtain an intermediate quantum optical signal; The intermediate quantum optical signal is polarized and filtered to obtain the second quantum optical signal.

4. The method according to claim 3, characterized in that, The polarization filtering is performed by a polarization filter device, which includes a single-photon detector. The count of the single-photon detector is used to indicate the amount of signal noise entering the single-photon detector.

5. The method according to claim 2, characterized in that, The multiplexing includes wavelength division multiplexing, time division multiplexing, mode division multiplexing, and space division multiplexing.

6. The method according to claim 1, characterized in that, The first quantum optical signal includes multiple sub-signals with different wavelengths, which are transmitted by time-division multiplexing.

7. A quantum optical signal processing device, characterized in that, The device includes: An initial quantum light pulse transmitting unit is used for transmitting an initial quantum light pulse, modulating the initial quantum light pulse in a single polarization direction to obtain a quantum light pulse, and encoding the quantum light pulse through a preset encoding dimension to obtain a quantum light signal; A multiplexing unit is used by the sender to multiplex the quantum optical signal and the classical optical signal to obtain a multiplexed optical signal, and then send the multiplexed optical signal to the receiver. A multiplexed optical signal receiving module is used for the receiver to receive multiplexed optical signals and to separate the multiplexed optical signals into a first quantum optical signal and a classical optical signal using a separation method corresponding to multiplexing; wherein, the first quantum optical signal corresponds to a first signal noise; A quantum optical signal filtering module is used by the receiver to perform polarization filtering on the first quantum optical signal to obtain a second quantum optical signal; wherein the polarization direction of the polarization filter is the same as the polarization direction of the quantum optical signal in the transmitter, the second quantum optical signal has a second signal noise, and the second signal noise is less than the first signal noise; the first signal noise and the second signal noise are in-band signal noise introduced by the classical optical signal, and the second signal noise is half of the first signal noise; The quantum key negotiation module is used by the receiver to decode the second quantum optical signal to obtain target information and negotiate a quantum key based on the target information.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the method as described in any one of claims 1 to 6.

9. An electronic device, characterized in that, include: One or more processors; as well as A memory for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement the method as described in any one of claims 1 to 6.

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