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

Abstract

A quantum optical signal processing method and apparatus, 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 (S110), the first quantum optical signal corresponding to first signal noise; polarization-filtering the first quantum optical signal to obtain a second quantum optical signal, the polarization direction of polarization filtering being the same as the polarization direction of the first quantum optical signal, the second quantum optical signal corresponding to second signal noise, and the second signal noise being lower than the first signal noise (S120); and decoding the second quantum optical signal to obtain target information, and negotiating for a quantum key on the basis of the target information (S130). The problem of low security key generation rate in the related art can be solved.

Description

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

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 202310981719.7, filed on August 4, 2023, entitled “Quantum Optical Signal Processing Method, Device, Storage Medium and Electronic Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of computer technology, and in particular to a quantum optical signal processing method, a quantum optical signal processing device, a computer-readable storage medium, and an electronic device. Background Art

[0004] Quantum Key Distribution (QKD) is a secure key exchange method that leverages the principles of quantum mechanics. It can generate and distribute keys during communications while ensuring key security. It has garnered widespread attention in recent years and is gradually moving from theoretical to practical application.

[0005] In related technologies, in order to accelerate the practical application of quantum key distribution, quantum optical signals and classical optical signals are usually transmitted on the same fiber.

[0006] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field.

[0007] Summary of the Invention

[0008] The present invention aims to provide a method for processing quantum optical signals, a device for processing quantum optical signals, a computer-readable storage medium, and an electronic device.

[0009] Other features and advantages of the present disclosure will become apparent from the following detailed description, or may be learned in part by practice of the present disclosure.

[0010] According to a first aspect of the present disclosure, a quantum light signal processing method is provided, which is applied to a receiving party. The method includes: receiving a multiplexed light signal, separating the multiplexed light signal to obtain a first quantum light signal and a classical light signal; wherein the first quantum light signal corresponds to a first signal noise; performing polarization filtering on the first quantum light signal to obtain a second quantum light signal; wherein the polarization direction of the polarization filtering is the same as the polarization direction of the first quantum light signal, the second quantum light signal corresponds to a second signal noise, and the second signal noise is less than the first signal noise; decoding the second quantum light signal to obtain target information, and negotiating a quantum key based on the target information.

[0011] According to a second aspect of the present disclosure, a quantum optical signal processing device is provided, which is applied to a receiving party. The device includes: a multiplexed optical signal receiving module, configured to receive a 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; a quantum optical signal filtering module, configured to perform 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; and a quantum key negotiation module, configured to decode the second quantum optical signal to obtain target information, and negotiate a quantum key based on the target information.

[0012] According to a third aspect of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored. When the program is executed by a processor, the quantum optical signal processing method according to the first aspect of the above embodiment is implemented.

[0013] According to a fourth aspect of the present disclosure, there is provided an electronic device, including:

[0014] one or more processors; and

[0015] The storage device is configured to store one or more programs. When the one or more programs are executed by one or more processors, the one or more processors implement the quantum optical signal processing method of the first aspect of the above embodiment.

[0016] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort. In the drawings:

[0018] FIG1 schematically shows a flow chart of a method for processing quantum optical signals in an exemplary embodiment of the present disclosure;

[0019] FIG2 schematically shows a flow chart of multiplexing a quantum optical signal with a classical optical signal to obtain a multiplexed optical signal and sending the multiplexed optical signal to a receiver in an exemplary embodiment of the present disclosure;

[0020] FIG3 schematically shows a flow chart of performing polarization filtering on an intermediate quantum light signal to obtain a second quantum light signal in an exemplary embodiment of the present disclosure;

[0021] FIG4 schematically shows a schematic diagram of a polarization modulation device in an exemplary embodiment of the present disclosure;

[0022] FIG5 schematically shows a schematic diagram of a co-fiber transmission device for classical optical communication and quantum key distribution in an exemplary embodiment of the present disclosure;

[0023] FIG6 schematically shows a composition diagram of a quantum optical signal processing device in an exemplary embodiment of the present disclosure;

[0024] FIG. 7 schematically shows a structural diagram of a computer system suitable for implementing an electronic device according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0025] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; on the contrary, these embodiments are provided so that the present disclosure will be more comprehensive and complete and the concepts of the example embodiments will be fully conveyed to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In addition, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of the specific details, or that other methods, components, devices, steps, etc. may be employed. In other cases, well-known structures, methods, devices, implementations, materials, or operations are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0026] The blocks shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically separate entities. Specifically, these functional entities may be implemented in software, or in one or more software-hardened modules, or in different networks and / or processor devices and / or microcontroller devices.

[0027] According to the quantum light signal processing method provided in this exemplary embodiment, a multiplexed light signal is received, and the multiplexed light signal is separated to obtain a first quantum light signal and a classical light signal, wherein the first quantum light signal corresponds to a first signal noise, and the first quantum light signal is polarization filtered to obtain a second quantum light signal, wherein the polarization direction of the polarization filtering is the same as the polarization direction of the first quantum light signal, and the second quantum light signal corresponds to a second signal noise, and the second signal noise is smaller than the first signal noise, and the second quantum light signal is decoded to obtain target information, and a quantum key is negotiated based on the target information.

[0028] As shown in FIG1 , the quantum optical signal processing method may include the following steps:

[0029] Step S110, 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;

[0030] Step S120, performing polarization filtering on the first quantum light signal to obtain a second quantum light signal; wherein the polarization direction of the polarization filtering is the same as the polarization direction of the first quantum light signal, the second quantum light signal corresponds to a second signal noise, and the second signal noise is smaller than the first signal noise;

[0031] Step S130: Decode the second quantum light signal to obtain target information, and negotiate a quantum key based on the target information.

[0032] In a quantum optical signal processing method provided by an embodiment of the present 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, wherein the first quantum optical signal corresponds to a first signal noise. The first quantum optical signal is polarization filtered 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 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 the present disclosure, the signal noise in the quantum optical signal can be filtered through polarization filtering, reducing the bit error rate of the quantum key distribution system, thereby improving the code rate and security key transmission distance of the quantum key distribution system.

[0033] Hereinafter, steps S110 to S130 of the quantum optical signal processing method in this exemplary embodiment will be described in more detail with reference to the accompanying drawings and embodiments.

[0034] Step S110, 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;

[0035] In an exemplary embodiment of the present disclosure, a multiplexed optical signal can be received and 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. A classical optical signal refers to an optical signal used in classical optics, which follows the laws and propagation methods of classical physics; a quantum optical signal refers to an 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; whereas quantum optical signals exhibit the particle characteristics of light, wave-particle duality, and discreteness limited by the measurement principle.

[0036] In an exemplary embodiment of the present 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 the multiplexed signal through multiplexing. That is, the multiplexed optical signal can be separated into the first quantum optical signal and the classical optical signal using a separation method corresponding to the multiplexing.

[0037] It should be noted that the present disclosure does not impose any particular limitation on the method of separating the multiplexed optical signals.

[0038] In an exemplary embodiment of the present disclosure, a first quantum optical signal corresponds to a first signal noise. Specifically, during the transmission of the multiplexed optical signal, the classical optical signal crosstalks into the quantum optical signal, thereby introducing classical noise. This is due to the fact that the classical optical signal has a higher intensity and its own noise floor is several orders of magnitude higher than that of the quantum optical signal. Furthermore, due to the nonlinear effects of optical fibers (such as the Raman effect and four-wave mixing effect), the introduced classical optical noise has a significant impact on the quantum optical signal.

[0039] It should be noted that the present disclosure does not impose any special limitation on the cause of the first signal noise.

[0040] Furthermore, when the multiplexed optical signal is separated to obtain the first quantum optical signal and the classical optical signal, out-of-band noise can be filtered by frequency domain filtering.

[0041] Through the solution disclosed in the present invention, the in-band signal noise introduced by the classical signal in the quantum optical signal can be filtered.

[0042] Step S120, performing polarization filtering on the first quantum light signal to obtain a second quantum light signal;

[0043] In an exemplary embodiment of the present disclosure, after obtaining a first quantum light signal through the above steps, polarization filtering can be performed on the first quantum light signal to obtain a second quantum light signal. The polarization direction of the polarization filtering is the same as that of the first quantum light signal, and the second quantum light signal has a second signal noise corresponding to the second quantum light signal, which is smaller than the first signal noise. Specifically, after receiving the first quantum light signal, polarization filtering can be performed on the first quantum light signal.

[0044] In an exemplary embodiment of the present disclosure, the polarization direction of the polarization filter is the same as the polarization direction of the first quantum light signal, which may include that the polarization direction of the polarization filter is the same as the polarization direction of the quantum light signal in the transmitter.

[0045] Specifically, since the polarization direction of the polarization filter is the same as that of the first quantum light signal, and the signal noise in the first quantum light signal maintains the original polarization state, when the first quantum light signal is polarized filtered, the first quantum light signal can pass normally, while the part of the signal noise corresponding to the first quantum light signal cannot pass normally, thereby achieving the effect of filtering the part of the signal noise corresponding to the first quantum light signal. Therefore, the second signal noise corresponding to the second quantum light signal obtained after polarization filtering is smaller than the first signal noise corresponding to the first quantum light signal.

[0046] It should be noted that the present disclosure does not impose any special limitation on the specific method of performing polarization filtering on the first quantum light signal to obtain the second quantum light signal.

[0047] Furthermore, the first quantum light signal can be controlled to enter a polarization beam splitter to perform polarization filtering on the first quantum light signal to obtain a second quantum light signal.

[0048] Among them, a polarization beam splitter is an optical component used to split the incident light into two output beams according to its polarization direction. The polarization beam splitter is usually composed of a special optical crystal or coating with different refractive indices and absorption properties, so that it has different transmission characteristics for light with different polarization directions. When the incident light enters the polarization beam splitter along one axis with a certain polarization direction (the same), most of the light will pass along the axis to form a transmitted beam, and a small amount of light will be reflected in another perpendicular direction to form a reflected beam; conversely, when the incident light enters with a polarization direction perpendicular to the first axis, the light will behave in the opposite way: most of the light will be reflected to form a reflected beam, while a small amount of light will be transmitted along the second axis to form a transmitted beam.

[0049] Step S130: Decode the second quantum light signal to obtain target information, and negotiate a quantum key based on the target information.

[0050] In an exemplary embodiment of the present disclosure, after obtaining a second quantum light signal through the above steps, the second quantum light signal can be decoded to obtain target information. Specifically, at the transmitter, a quantum light pulse can be encoded according to a preset coding dimension to obtain a quantum light signal. The quantum light signal and a classical light signal can be multiplexed to form a multiplexed light signal, which is transmitted to the receiver. At the receiver, a preset decoding method corresponding to the preset coding dimension can be used to decode the second quantum light signal to obtain the target information.

[0051] It should be noted that the present disclosure does not impose any special limitation on the specific method of decoding the second quantum light signal to obtain the target information.

[0052] In an exemplary embodiment of the present disclosure, after obtaining the target information 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 perform error correction on the target information via a public classical channel to generate a shared key.

[0053] In an exemplary embodiment of the present disclosure, any eavesdropping or tampering of the quantum signal during transmission is immediately detected due to the irreversibility of quantum mechanics and the principle of measurement. Therefore, the next step is only taken when the channel security is confirmed.

[0054] Specifically, after the receiver obtains the target information, the sender and receiver can exchange other target information through a public classical channel. The sender and receiver use classical computing methods to compare each other's target information and, based on a pre-agreed protocol, determine the content in 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 key for encryption and decryption.

[0055] During this process, error correction codes and randomization processes can be used to deal with errors and noise introduced during channel transmission.

[0056] It should be noted that the present disclosure does not specifically limit the specific method of negotiating the quantum key based on the target information.

[0057] In an exemplary embodiment of the present disclosure, an initial quantum light pulse may be emitted, polarization modulated on the initial quantum light pulse to obtain a quantum light pulse, the quantum light pulse may be encoded using a preset coding dimension to obtain a quantum light signal, the quantum light signal may be multiplexed with a classical light signal to obtain a multiplexed light signal, and the multiplexed light signal may be sent to a receiver. Referring to FIG. 2 , multiplexing the quantum light signal with the classical light signal to obtain a multiplexed light signal and sending the multiplexed light signal to a receiver may include the following steps S210 to S220:

[0058] Step S210, emitting an initial quantum light pulse, performing polarization modulation on the initial quantum light pulse to obtain a quantum light pulse, and encoding the quantum light pulse using a preset coding dimension to obtain a quantum light signal;

[0059] In an exemplary embodiment of the present disclosure, an initial quantum light pulse may be emitted and polarization modulated to obtain a quantum light pulse. Specifically, the initial quantum light pulse may be emitted by a laser, and a polarization modulation device may be provided in the laser. The polarization modulation device may be used to polarize modulate the initial quantum light pulse to obtain the 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.

[0060] In an exemplary embodiment of the present disclosure, a quantum light pulse can be encoded using a preset coding dimension to obtain a quantum light signal. Specifically, after obtaining the quantum light pulse, the quantum light pulse can be encoded using the preset coding dimension to obtain a quantum light signal in a specific coding state. For example, the quantum light pulse can be encoded using phase coding to obtain a quantum light signal carrying phase information.

[0061] It should be noted that the present disclosure does not impose any particular limitation on the specific method of encoding quantum light pulses.

[0062] Step S220 , multiplexing the quantum optical signal and the classical optical signal to obtain a multiplexed optical signal, and sending the multiplexed optical signal to a receiver.

[0063] In an exemplary embodiment of the present disclosure, after obtaining a quantum optical signal through the above steps, the quantum optical signal can be multiplexed with a classical optical signal to obtain a multiplexed optical signal. Specifically, multiplexing the quantum optical signal with the classical optical signal involves 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 resulting multiplexed optical signal to a receiver. After the receiver obtains the multiplexed optical signal, it can use a separation method corresponding to the multiplexing method to decompose the multiplexed optical signal into the quantum optical signal and the classical optical signal.

[0064] For example, multiplexing of quantum optical signals and classical optical signals can be achieved through optical wavelength division multiplexers, optical mode division multiplexers, multi-core fiber fan-in and fan-out devices, etc. These devices can merge different optical signals into the same optical fiber.

[0065] In an exemplary embodiment of the present disclosure, multiplexing includes wavelength division multiplexing, time division multiplexing, mode division multiplexing, and space division multiplexing.

[0066] It should be noted that the present disclosure does not impose any particular limitation on the specific method of multiplexing the quantum light signal and the classical light signal to obtain the multiplexed light signal.

[0067] Through the above steps S210 to S220, an initial quantum light pulse can be emitted, the initial quantum light pulse can be polarization modulated to obtain a quantum light pulse, the quantum light pulse can be encoded using a preset coding 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 sent to a receiver.

[0068] In an exemplary embodiment of the present disclosure, the polarization state of a first quantum light signal can be modulated to the same polarization state as a quantum light signal in a transmitter to obtain an intermediate quantum light signal, and polarization filtering is performed on the intermediate quantum light signal to obtain a second quantum light signal. Referring to FIG. 3 , polarization filtering of the intermediate quantum light signal to obtain the second quantum light signal may include the following steps S310 to S320:

[0069] Step S310, modulating the polarization state of the first quantum light signal to the same polarization state as the quantum light signal in the transmitter to obtain an intermediate quantum light signal;

[0070] In an exemplary embodiment of the present disclosure, after obtaining the first quantum light signal through the above steps, the polarization state of the first quantum light signal can be modulated to the same polarization state as the quantum light signal in the sender to obtain an intermediate quantum light signal. Specifically, at the sender, the initial quantum light pulse can be polarization modulated to obtain a quantum light pulse, and the quantum light pulse can be encoded using a preset coding dimension to obtain a quantum light signal, and the quantum light signal can be multiplexed with the classical light signal to obtain a multiplexed light signal, that is, the quantum light signal in the sender has a corresponding polarization state. Because the polarization state of the quantum light signal changes during the transmission of the multiplexed light signal, after the receiver receives the multiplexed light signal and separates it to obtain the first quantum light signal, the polarization state of the first quantum light signal can be adjusted so that the polarization state of the intermediate quantum light signal after adjustment is the same as the polarization state of the quantum light signal in the sender, thereby compensating for the change in the polarization state of the quantum light signal during long-distance transmission.

[0071] It should be noted that the present disclosure does not impose any special limitation on the specific method of modulating the polarization state of the first quantum light signal to the same polarization state as the quantum light signal in the transmitter.

[0072] Step S320: Perform polarization filtering on the intermediate quantum light signal to obtain a second quantum light signal.

[0073] In an exemplary embodiment of the present disclosure, after obtaining an intermediate quantum light signal through the above steps, polarization filtering can be performed on the intermediate quantum light signal to obtain a second quantum light signal. Specifically, after the polarization state of the first quantum light signal is modulated to the same polarization state as the quantum light signal in the transmitter, the polarization direction of the intermediate quantum light signal is the same as the polarization direction of the polarization filter and the polarization direction of the quantum light signal in the transmitter. That is, the intermediate quantum light signal can pass normally, while the portion of signal noise corresponding to the intermediate quantum light signal cannot pass normally, thereby achieving the effect of filtering the portion of signal noise corresponding to the intermediate quantum light signal. As a result, the second signal noise corresponding to the second quantum light signal obtained after polarization filtering is less than the first signal noise corresponding to the first quantum light signal.

[0074] Furthermore, the intermediate quantum light signal can be controlled to pass through a polarization beam splitter to obtain a second quantum light signal, wherein the polarization direction of the polarization beam splitter is the polarization direction of the polarization filter.

[0075] Through steps S310-S320, the polarization state of the first quantum light signal can be modulated to the same polarization state as the quantum light signal in the transmitter, obtaining an intermediate quantum light signal. Polarization filtering of the intermediate quantum light signal is then performed to obtain a second quantum light signal. The disclosed solution can compensate for offsets during quantum light signal transmission, improving the transmission efficiency of quantum light signals.

[0076] In an exemplary embodiment of the present disclosure, polarization filtering can be performed using a polarization filtering device. Specifically, the polarization filtering device can be used to polarize filter a first quantum light signal to obtain a second quantum light signal. The polarization filtering device 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. When the polarization state of the first quantum light signal is modulated to the same polarization state as the quantum light signal from the sender, the count of the single-photon detector is minimized. Specifically, if the count of the single-photon detector is large, it indicates that the polarization state of a portion of the first quantum light signal is different from the polarization state of the quantum light signal from the sender. In this case, the polarization state of the first quantum light signal can be further modulated so that the polarization state of the modulated intermediate quantum light signal is the same as the polarization state of the quantum light signal from the sender. When the polarization state of the first quantum light signal is the same as the polarization state of the quantum light signal from the sender, the count of the single-photon detector is minimized.

[0077] In one exemplary embodiment of the present disclosure, the first and second signal noises are in-band signal noise introduced by the classical optical signal, with the second signal noise being half the first signal noise. Specifically, in-band signal noise refers to the noise component 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 from the sender can be received by the receiver. In-band signal noise with a different polarization state than the quantum optical signal from the sender is partially filtered out due to polarization filtering.

[0078] Specifically, Malus's law can be used to filter out the signal noise in the first quantum light signal that differs from the polarization state of the quantum light signal at the sender. Thus, half of the in-band signal noise in the first quantum light signal can be filtered out to obtain a second quantum light signal, where the second signal noise is less than the first signal noise. The disclosed solution can increase the signal-to-noise ratio of quantum key distribution by a factor of two, reducing the bit error rate of the quantum key distribution system, thereby improving the system's code rate and secure key transmission distance.

[0079] In an exemplary embodiment of the present disclosure, a first quantum optical signal includes multiple sub-signals, each having different wavelengths, and is transmitted via time-division multiplexing. Specifically, at the transmitter, the multiple quantum optical signals (sub-signals) can be multiplexed with a classical optical signal to produce a multiplexed optical signal. After receiving the multiplexed optical signal, the receiver can separate the multiplexed optical signal to produce multiple sub-signals and a classical optical signal. Each sub-signal can then be transmitted via time-division multiplexing.

[0080] Specifically, when multiple sub-signals of different wavelengths are transmitted in sequence according to 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 the remaining wavelengths.

[0081] In an exemplary embodiment of the present disclosure, as shown in FIG4 , a polarization modulation device is provided. The polarization modulation device may include an electrically controlled polarization controller, a polarization beam splitter, and a single-photon detector. The electrically controlled polarization controller may modulate the polarization state of a first quantum light signal to the same polarization state as the quantum light signal in the transmitter, thereby obtaining an intermediate quantum light signal. The polarization beam splitter may be configured to filter out the in-band signal noise in the intermediate quantum light signal that differs from the polarization state of the quantum light signal in the transmitter. The single-photon detector may be configured to record the number of quantum light signals entering the single-photon detector. When the polarization state of the first quantum light signal is modulated to the same polarization state as the quantum light signal in the transmitter, the count of the single-photon detector is minimized.

[0082] In an exemplary embodiment of the present disclosure, as shown in FIG5 , a co-fiber transmission device for classical optical communication and quantum key distribution is provided.

[0083] In the transmitter of the device, multiple sub-signals can be transmitted through multiple quantum key distribution transmitting ends, and different quantum key distribution transmitting ends use different wavelengths. The quantum key distribution transmitting end can include a laser and a phase encoding device, wherein the laser can be configured to emit an initial quantum light pulse, and the initial quantum light pulse is polarization-modulated to obtain a quantum light pulse. The phase encoding device can be configured to perform phase encoding on the quantum light pulse to obtain a sub-signal (quantum light signal) loaded with phase information, and the multiple sub-signals with phase information obtained are wavelength-division multiplexed with the classical light signal through a wavelength division multiplexer to obtain a multiplexed light signal, which is transmitted to the receiver through an optical communication network and an optical amplifier.

[0084] In the receiver of the device, the multiplexed optical signal can be separated by a wavelength division multiplexer to obtain multiple sub-signals (the first quantum optical signal includes multiple sub-signals, which are quantum optical signals) and classical optical signals, and the multiple sub-signals are transmitted to each quantum key distribution receiving end through a delay line. The quantum key distribution receiving end includes the above-mentioned polarization modulation device, through which part of the signal noise in the sub-signal can be filtered to obtain a second quantum optical signal, and then the second quantum optical signal is decoded by a phase decoding device to obtain target information.

[0085] The signal processing solution provided by this disclosure can be directly integrated with existing OTN (Optical Transport Network) equipment, and can accelerate the large-scale deployment of quantum key distribution systems without the need for customized modifications.

[0086] In a quantum optical signal processing method provided by an embodiment of the present 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, wherein the first quantum optical signal corresponds to a first signal noise. The first quantum optical signal is polarization filtered 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 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 the present disclosure, the signal noise in the quantum optical signal can be filtered through polarization filtering, reducing the bit error rate of the quantum key distribution system, thereby improving the code rate and security key transmission distance of the quantum key distribution system.

[0087] It should be noted that the above figures are merely illustrative of the processes included in the methods according to exemplary embodiments of the present disclosure and are not intended to be limiting. It is readily understood that the processes illustrated 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.

[0088] In addition, in an exemplary embodiment of the present disclosure, a quantum optical signal processing device is also provided. Referring to FIG6 , 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 agreement module 630 .

[0089] Among them, the multiplexed optical signal receiving module is configured to 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; the quantum optical signal filtering module is configured to perform 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; the quantum key negotiation module is configured to decode the second quantum optical signal to obtain target information, and negotiate the quantum key based on the target information.

[0090] In an exemplary embodiment of the present disclosure, based on the aforementioned scheme, applied to the sender, the device also includes: an initial quantum light pulse emission unit, configured to emit an initial quantum light pulse, polarization modulate the initial quantum light pulse to obtain a quantum light pulse, and encode the quantum light pulse through a preset coding dimension to obtain a quantum light signal; a multiplexing unit, configured to multiplex the quantum light signal with the classical light signal to obtain a multiplexed light signal, and send the multiplexed light signal to the receiver.

[0091] In an exemplary embodiment of the present disclosure, based on the aforementioned scheme, polarization filtering is performed on the first quantum light signal to obtain a second quantum light signal. The device also includes: a polarization state modulation unit, configured to modulate the polarization state of the first quantum light signal to the same polarization state as the quantum light signal in the transmitter to obtain an intermediate quantum light signal; and a second quantum light signal acquisition unit, configured to polarization filter the intermediate quantum light signal to obtain the second quantum light signal.

[0092] In an exemplary embodiment of the present disclosure, based on the aforementioned scheme, polarization filtering is performed through 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. When the polarization state of the first quantum light signal is modulated to the same polarization state as the quantum light signal in the sender, the count of the single-photon detector is minimized.

[0093] In an exemplary embodiment of the present disclosure, based on the aforementioned solution, the first signal noise and the second signal noise are in-band signal noise introduced by a classical optical signal, and the second signal noise is half of the first signal noise.

[0094] In an exemplary embodiment of the present disclosure, based on the aforementioned solution, multiplexing includes wavelength division multiplexing, time division multiplexing, mode division multiplexing, and space division multiplexing.

[0095] In an exemplary embodiment of the present disclosure, based on the aforementioned solution, the first quantum optical signal includes multiple sub-signals, the multiple sub-signals have different wavelengths, and the multiple sub-signals are transmitted by time division multiplexing.

[0096] Since the functional modules of the quantum optical signal processing device of the exemplary embodiment of the present disclosure correspond to the steps of the exemplary embodiment of the quantum optical signal processing method described above, for details not disclosed in the embodiment of the device of the present disclosure, please refer to the embodiment of the quantum optical signal processing method described above.

[0097] It should be noted that although several modules or units of the device configured to perform an action are mentioned in the above detailed description, this division is not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more modules or units described above can be concretized in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided into multiple modules or units to be concretized.

[0098] In addition, in an exemplary embodiment of the present disclosure, an electronic device capable of implementing the above-mentioned quantum optical signal processing method is also provided.

[0099] Those skilled in the art will appreciate that various aspects of the present disclosure may be implemented as systems, methods, or program products. Therefore, various aspects of the present disclosure may be implemented in the following forms: a complete hardware embodiment, a complete software embodiment (including firmware, microcode, etc.), or an embodiment combining hardware and software aspects, which may be collectively referred to herein as a "circuit," "module," or "system."

[0100] The electronic device 700 according to this embodiment of the present disclosure is described below with reference to Figure 7. The electronic device 700 shown in Figure 7 is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0101] As shown in FIG7 , electronic device 700 is implemented as a general-purpose computing device. Components of electronic device 700 may include, but are not limited to, the aforementioned at least one processing unit 710, the aforementioned at least one storage unit 720, a bus 730 connecting various system components (including storage unit 720 and processing unit 710), and a display unit 740.

[0102] The storage unit stores program code, and the program code can be executed by the processing unit 710, so that the processing unit 710 performs the steps described in the "Exemplary Method" section of the present specification according to various exemplary embodiments of the present disclosure. For example, the processing unit 710 can execute step S110 as shown in Figure 1, receive a multiplexed optical signal, 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; step S120, polarization filtering 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 less than the first signal noise; step S130, decode the second quantum optical signal to obtain target information, and negotiate a quantum key based on the target information.

[0103] For another example, the electronic device can implement the steps shown in FIG1 .

[0104] The storage unit 720 may include a readable medium in the form of a volatile storage unit, such as a random access memory unit (RAM) 721 and / or a cache memory unit 722 , and may further include a read-only memory unit (ROM) 723 .

[0105] The storage unit 720 may also include a program / utility 724 having a set (at least one) of program modules 725, such program modules 725 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0106] Bus 730 may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0107] The electronic device 700 can also communicate with one or more external devices 770 (e.g., a keyboard, a pointing device, a Bluetooth device, etc.), one or more devices that enable a user to interact with the electronic device 700, and / or any device that enables the electronic device 700 to communicate with one or more other computing devices (e.g., a router, a modem, etc.). Such communication can occur via an input / output (I / O) interface 750. Furthermore, the electronic device 700 can also communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network such as the Internet) via a network adapter 760. As shown, the network adapter 760 communicates with other modules of the electronic device 700 via a bus 730. It should be understood that, although not shown in the figure, other hardware and / or software modules can be used in conjunction with the 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.

[0108] Through the description of the above embodiments, it is easy for those skilled in the art to understand that the example embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solution according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes a number of instructions to enable a computing device (which can be a personal computer, a server, a terminal device, or a network device, etc.) to execute the method according to the embodiments of the present disclosure.

[0109] In exemplary embodiments of the present disclosure, a computer-readable storage medium is also provided, on which is stored a program product capable of implementing the aforementioned methods of this specification. In some possible embodiments, various aspects of the present disclosure may also be implemented in the form of a program product, which includes program code. When the program product is executed on a terminal device, the program code is used to cause the terminal device to execute the steps according to various exemplary embodiments of the present disclosure described in the "Exemplary Methods" section of this specification.

[0110] A computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries readable program code. Such propagated data signals may take a variety of 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 that can transmit, propagate, or transfer a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0111] The program code embodied on the readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0112] Program code for performing the operations of the present disclosure may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java, C++, and the like, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code may be executed entirely on the user computing device, partially on the user device, as a stand-alone software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving a remote computing device, the remote computing device may be connected to the user computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0113] Furthermore, the figures above are merely illustrative of the processes included in the methods according to exemplary embodiments of the present disclosure and are not intended to be limiting. It is readily understood that the processes illustrated in the figures above 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.

[0114] Other embodiments of the present disclosure will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This disclosure is intended to cover any variations, uses, or adaptations of the present disclosure that follow from the general principles of the present disclosure and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present disclosure being indicated by the claims.

Claims

1. A quantum light signal processing method, applied to a receiving side, the method comprising: 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 light signal to obtain a second quantum light signal; wherein the polarization direction of the polarization filtering is the same as the polarization direction of the first quantum light signal, the second quantum light signal corresponds to a second signal noise, and the second signal noise is less than the first signal noise; The second quantum light signal is decoded to obtain target information, and a quantum key is negotiated according to the target information.

2. The method according to claim 1, wherein: Applied to the sender, the method further includes: Emitting an initial quantum light pulse, performing polarization modulation on the initial quantum light pulse to obtain a quantum light pulse, and encoding the quantum light pulse through a preset coding dimension to obtain a quantum light signal; 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.

3. The method according to claim 2, wherein: The step of performing polarization filtering on the first quantum light signal to obtain a second quantum light signal includes: Modulating the polarization state of the first quantum light signal to be the same as the polarization state of the quantum light signal in the transmitter to obtain an intermediate quantum light signal; Polarization filtering is performed on the intermediate quantum light signal to obtain a second quantum light signal.

4. The method according to claim 3, wherein: The 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. When the polarization state of the first quantum light signal is modulated to the same polarization state as the quantum light signal in the sender, the count of the single-photon detector is minimum.

5. The method according to claim 3, wherein: The first signal noise and the second signal noise are in-band signal noise introduced by a classical optical signal, and the second signal noise is half of the first signal noise.

6. The method according to claim 2, wherein: The multiplexing includes wavelength division multiplexing, time division multiplexing, mode division multiplexing and space division multiplexing.

7. The method according to claim 1, wherein: The first quantum optical signal includes a plurality of sub-signals, the plurality of sub-signals have different wavelengths, and the plurality of sub-signals are transmitted by time division multiplexing.

8. A quantum light signal processing device, applied to a receiving side, comprising: A multiplexed optical signal receiving module, configured to receive a 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; a quantum light signal filtering module, configured to perform polarization filtering on the first quantum light signal to obtain a second quantum light signal; wherein the polarization direction of the polarization filtering is the same as the polarization direction of the first quantum light signal, and the second The two-quantum light signal corresponds to a second signal noise, and the second signal noise is smaller than the first signal noise; The quantum key negotiation module is configured to decode the second quantum light signal to obtain target information and negotiate a quantum key according to the target information.

9. A computer-readable storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the method according to any one of claims 1 to 7.

10. An electronic device comprising: one or more processors; as well as The memory is configured to store one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 7.

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