WO2017206567A1 - 一种量子通信方法和相关装置 - Google Patents

一种量子通信方法和相关装置 Download PDF

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Publication number
WO2017206567A1
WO2017206567A1 PCT/CN2017/076830 CN2017076830W WO2017206567A1 WO 2017206567 A1 WO2017206567 A1 WO 2017206567A1 CN 2017076830 W CN2017076830 W CN 2017076830W WO 2017206567 A1 WO2017206567 A1 WO 2017206567A1
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Prior art keywords
optical signal
band
sub
classical
quantum
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PCT/CN2017/076830
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English (en)
French (fr)
Inventor
苏长征
陆亮亮
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华为技术有限公司
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Priority to EP17805512.5A priority Critical patent/EP3454483A4/en
Priority to KR1020187037263A priority patent/KR102193074B1/ko
Priority to JP2018562282A priority patent/JP6866977B2/ja
Publication of WO2017206567A1 publication Critical patent/WO2017206567A1/zh
Priority to US16/206,452 priority patent/US10778341B2/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L9/00—Cryptographic mechanisms or cryptographic arrangements for secret or secure communications; Network security protocols
    • H04L9/08—Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords
    • H04L9/0816—Key establishment, i.e. cryptographic processes or cryptographic protocols whereby a shared secret becomes available to two or more parties, for subsequent use
    • H04L9/0852—Quantum cryptography
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/70—Photonic quantum communication
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/25—Arrangements specific to fibre transmission
    • H04B10/2507—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
    • H04B10/2537—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to scattering processes, e.g. Raman or Brillouin scattering
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/50—Transmitters
    • H04B10/501—Structural aspects
    • H04B10/506—Multiwavelength transmitters
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems

Definitions

  • Embodiments of the present invention relate to the field of communications technologies, and in particular, to a quantum communication method and related apparatus.
  • QKD Quantum Key Distribution
  • the implementation is achieved by encoding a set of random numbers on the quantum state of the quantum optical signal at the transmitting device, being detected by the receiver of the receiving device after being transmitted through the quantum channel, and then transmitting the device and The receiving device passes through a series of processing procedures such as data comparison and negotiation of the classic channel, and finally causes the two parties to share a set of secure random number keys.
  • the fiber used for communication between the transmitting device and the receiving device carries only quantum signals, which facilitates the detection of quantum signals because no other optical signals introduce additional noise.
  • quantum communication will inevitably develop in the direction of networking and globalization.
  • WDM Wavelength Division Multiplexing
  • WDM is a combination of two or more optical carrier signals of different wavelengths (carrying various kinds of information) in a transmitting device via a multiplexer (also called a combiner) and coupled to the same fiber of the optical line.
  • a demultiplexer also called a demultiplexer or a demultiplexer
  • a demultiplexer separates optical carriers of various wavelengths, and then further processes by the optical receiver to recover Original signal.
  • the L-band wavelength ranges from 1565 nanometers (nm) to 1625 nm
  • the C-band wavelength ranges from 1530 nm to 1565 nm
  • the S-band wavelength ranges from 1460 nm to 1530 nm
  • the E-band wavelength ranges from 1360 nm.
  • the O-wavelength range is from 1260 nm to 1360 nm.
  • a solution for realizing the mixing of classical signals and quantum signals in the same fiber is to transmit classical optical signals in the C-band based on WDM technology and to transmit the quantum optical signals in the L-band.
  • Raman noise is generated by inelastic scattering of pump photons and optical phonons
  • the generated scattered photon wavelength is smaller or larger than the pumping light, corresponding to the anti-Stokes scattering region and Stoke, respectively. Scattering area. Since the scattering intensity of the Stokes scattering region is larger than that of the anti-Stokes scattering region, when the quantum light signal is placed in the longer wavelength L-band, the quantum light signal is mainly affected by the Stokes scattering region. At this time, the quantum light signal is greatly affected by the Raman noise.
  • Embodiments of the present invention provide a quantum communication method and related apparatus for using a classic optical signal and a quantum optical signal When mixed by an optical fiber, the influence of Raman noise on the quantum optical signal is reduced.
  • An embodiment of the present invention provides a transmitting apparatus for quantum communication, including:
  • a quantum optical signal transmitter for generating a quantum optical signal; the wavelength of the quantum optical signal is in the S-band;
  • a first coupling unit configured to couple the optical signal to be processed and the quantum optical signal to obtain a coupled optical signal
  • a sending unit configured to send the coupled optical signal through the optical fiber
  • the classical optical signal of the to-be-processed optical signal includes at least one sub-classical optical signal; when the classical optical signal includes a sub-classical optical signal, the wavelength of the sub-classical optical signal is in the C-band or the L-band;
  • the plurality of sub-classical optical signals satisfy any one of the following: the plurality of sub-classical optical signals include sub-classical optical signals having wavelengths in the C-band; and the plurality of sub-classical optical signals include wavelengths The sub-classical optical signal in the L-band; the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band.
  • the wavelength of the classical optical signal is in the L-band and/or the C-band. Since the wavelength of the quantum optical signal is in the S-band, the wavelength of the band of the classical optical signal is greater than the wavelength of the band of the quantum optical signal. Therefore, the quantum optical signal can be located.
  • the anti-Stokes scattering region because of the small scattering intensity of the anti-Stokes scattering region, can effectively reduce the influence of the Raman noise on the quantum optical signal, thereby improving the classic transmission through a fiber.
  • the wavelength of the quantum optical signal is in the S-band, and since the attenuation coefficient of the optical fiber of the S-band is small, when the quantum optical signal is transmitted in the S-band with a small insertion loss, the loss of the quantum optical signal can be reduced, thereby improving The safe distance of quantum key transmission.
  • the wavelength of the classical optical signal is in the L-band and/or C-band
  • the wavelength of the quantum optical signal is in the S-band, that is, the band of the classical optical signal and the band of the quantum optical signal are two different bands, thereby ensuring the classic
  • the distance between the wavelength of the optical signal and the wavelength of the quantum optical signal can effectively reduce the interference caused by the leakage of the classical optical signal to the quantum optical signal, and effectively reduce the four waves generated by the classical optical signal during transmission.
  • FWM Four-Wave Mixing
  • the first coupling unit is specifically configured to transmit the to-be-processed optical signal transmitted on the first sub-fiber in the optical fiber and the second sub-fiber in the optical fiber through an S-band coupler located on the optical fiber.
  • the quantum optical signals are coupled to obtain a coupled optical signal.
  • the S-band coupler can be a fiber coupler, or a S-band quantum optical signal and a wavelength division multiplexer of the optical signal to be processed.
  • the classical optical signal transmitter is specifically configured to generate a classical optical signal, and attenuates the generated classical optical signal by using a variable optical attenuator (VOA) to obtain an optical signal to be processed.
  • VOA variable optical attenuator
  • the classical optical signal is attenuated using the VOA on the transmitting device side, the EDFA commonly used in the prior art is not used, and thus the influence of the ASE noise caused by the EDFA on the QKD channel is completely eliminated.
  • the optical power requirement for the classic optical is lower for the metropolitan area network communication system.
  • the classical optical signal is attenuated by using the VOA, and the power of the classical optical signal can be completely achieved. Transmission requirements.
  • the optical signal to be processed further includes a monitoring optical signal, wherein the monitoring optical signal is located in the L-band.
  • the classic optical signal transmitter is specifically used to generate classic optical signals and monitor optical signals, and attenuates the generated classical optical signals through VOA to obtain attenuated classical optical signals; after being attenuated by L-band and C-band combiners The classic optical signal is coupled to the monitored optical signal to obtain an optical signal to be processed.
  • an optical amplification station is set in the actual transmission process, in this way
  • the transmission line can be monitored by the monitoring optical signal sent by the first optical monitoring channel 2207, which improves the security of the transmission, and is better compatible with the prior art.
  • the layout of the monitoring channel thirdly, since the monitoring optical signal uses the L-band, the band of the monitoring optical signal is far from the wavelength band of the quantum optical signal, and therefore, the monitoring optical signal has less influence on the noise of the quantum optical signal.
  • the classical optical signal transmitter is specifically configured to couple the plurality of sub-classical optical signals by the first coupler or the combiner to obtain a classical optical signal.
  • the combiner meets the following conditions:
  • the plurality of sub-classical optical signals include sub-classical optical signals with wavelengths in the C-band, and the combiner is a C-band combiner; the plurality of sub-classical optical signals include sub-classical optical signals having wavelengths in the L-band, and the combiner is the L-band
  • the combiner includes a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band, and the combiner is a C-band and an L-band combiner.
  • a plurality of sub-classical optical signals are coupled by a first coupler or combiner to obtain a classical optical signal.
  • the communication system can be simplified, the operation is facilitated, and the insertion loss in the system is further reduced.
  • the quantum optical signal transmitter is specifically configured to couple the plurality of sub-quantum optical signals by the second coupler or the S-band combiner to obtain a quantum optical signal. Since the quantum optical signal and the transmitted optical signal are mixed and transmitted in one optical fiber, the quantum optical signal is inevitably affected by certain noise and the quantum key generation rate is lowered, in order to reduce the quantum key generation rate. Further, the quantum key generation rate is further improved.
  • multiple sub-quantum optical signals are simultaneously transmitted through multiple wavelengths, thereby increasing the transmission rate of the sub-quantum optical signals, thereby increasing the generation rate of the quantum key, thereby enabling More classical optical signals are encrypted, which improves the communication efficiency of quantum communication.
  • An embodiment of the present invention provides a receiving apparatus for quantum communication, including:
  • a receiving unit configured to receive, by the optical fiber, the coupled optical signal sent by the transmitting device; wherein the coupled optical signal includes the optical signal to be processed and the quantum optical signal; the wavelength of the quantum optical signal is in the S-band;
  • a second coupling unit configured to determine a to-be-processed optical signal and a quantum optical signal from the coupled optical signal
  • a classical optical signal receiver configured to receive an optical signal to be processed outputted by the second coupling unit, and determine a classical optical signal from the optical signal to be processed
  • a quantum optical signal receiver for receiving and processing a quantum optical signal output by the second coupling unit
  • the classical optical signal of the to-be-processed optical signal includes at least one sub-classical optical signal; when the classical optical signal includes a sub-classical optical signal, the wavelength of the sub-classical optical signal is in the C-band or the L-band;
  • the plurality of sub-classical optical signals satisfy any one of the following: the plurality of sub-classical optical signals include sub-classical optical signals having wavelengths in the C-band; and the plurality of sub-classical optical signals include wavelengths The sub-classical optical signal in the L-band; the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band.
  • the wavelength of the classical optical signal is in the L-band and/or the C-band. Since the wavelength of the quantum optical signal is in the S-band, the wavelength of the band of the classical optical signal is greater than the wavelength of the band of the quantum optical signal. Therefore, the quantum optical signal can be located.
  • the anti-Stokes scattering region because of the small scattering intensity of the anti-Stokes scattering region, can effectively reduce the influence of the Raman noise on the quantum optical signal, thereby improving the classic transmission through a fiber.
  • the wavelength of the quantum optical signal is in the S-band, and since the attenuation coefficient of the optical fiber of the S-band is small, when the quantum optical signal is transmitted in the S-band with a small insertion loss, the loss of the quantum optical signal can be reduced, thereby improving Amount The safe distance for subkey transmission.
  • the wavelength of the classical optical signal is in the L-band and/or C-band
  • the wavelength of the quantum optical signal is in the S-band, that is, the band of the classical optical signal and the band of the quantum optical signal are two different bands, thereby ensuring the classic
  • the distance between the wavelength of the optical signal and the wavelength of the quantum optical signal can effectively reduce the interference caused by the leakage of the classical optical signal to the quantum optical signal, and effectively reduce the FWM pair generated by the classical optical signal during transmission. Interference caused by quantum light signals.
  • the second coupling unit is configured to separate the quantum optical signal in the coupled optical signal into the fourth sub-fiber in the optical fiber through an S-band bandpass filter located on the optical fiber;
  • the optical signal to be processed in the signal is separated into a third sub-fiber in the optical fiber for processing, and a classical optical signal is determined from the optical signal to be processed.
  • the S-band bandpass filter may separate the quantum optical signal in the coupled optical signal to the fourth sub-fiber in the optical fiber, and separate the optical signal to be processed in the coupled optical signal to The third sub-fiber in the optical fiber is processed, so that the classical optical signal and the quantum optical signal are transmitted through one optical fiber, and then processed separately.
  • the quantum light signal can be filtered first by the S-band band pass filter, thereby reducing the influence of noise photons.
  • the bandwidth of the S-band bandpass filter 2106 is from 0.1 nm to 5 nm.
  • the bandwidth of the S-band bandpass filter 2106 can be made 0.6 nm in practical applications.
  • the bandwidth of the S-band bandpass filter 2106 needs to cover the wavelengths of the plurality of sub-quantum optical signals, or need to cover the wavelength range of the entire S-band, optionally, the S-band bandpass The bandwidth of the filter 2106 ranges from 0.1 nm to 70 nm.
  • the classical optical signal receiver is specifically configured to amplify the optical signal to be processed by using an optical amplifier (OA) to obtain a classical optical signal.
  • OA optical amplifier
  • the amplification of the classical optical signal by OA does not affect the quantum optical signal, and since the classical optical signal is lost when transmitted through the optical fiber, the classical optical signal is amplified and processed by OA, thereby improving the classic light. The accuracy of signal processing.
  • the optical signal to be processed further includes a monitoring optical signal, wherein the monitoring optical signal is located in the L-band.
  • the classical optical signal receiver is specifically used for splitting the optical signal to be processed by the L-band and C-band splitter to obtain a monitor optical signal and a split-wave optical signal; and the OA, the split-wave optical signal is amplified, Get a classic light signal.
  • an optical amplifying station is set in the actual transmission process, in which case the monitoring optical signal pair that can be transmitted through the first optical monitoring channel 2207 is present due to the presence of the intermediate node.
  • the transmission line is monitored to improve the security of the transmission.
  • it is better compatible with the layout of the monitoring channel in the prior art.
  • the monitoring optical signal uses the L-band, the band distance quantum of the monitoring optical signal is monitored.
  • the optical signal has a relatively long wavelength band. Therefore, the monitoring optical signal has less influence on the noise of the quantum optical signal.
  • the classical optical signal receiver is further configured to perform a demultiplexing process on the classical optical signal by using a splitter to obtain a plurality of sub-classical lights included in the classical optical signal. signal.
  • the splitter meets the following conditions:
  • the plurality of sub-classical optical signals include sub-classical optical signals with wavelengths in the C-band, and the splitter is a C-band splitter; the plurality of sub-classical optical signals include sub-classical optical signals with wavelengths in the L-band, and the splitter is L-band The splitter; the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band, and the splitter is a C-band and an L-band splitter.
  • the quantum optical signal receiver is further configured to perform a wavelet processing on the quantum optical signal by using an S-band splitter to obtain a plurality of sub-segments included in the quantum optical signal.
  • Quantum optical signal Such as
  • a plurality of sub-classical optical signals can be separated by simultaneously receiving a plurality of sub-classical optical signals through a plurality of wavelengths. In this way, more sub-classical optical signals can be transmitted simultaneously.
  • each subband of the S-band splitter has a bandwidth ranging from 0.1 nm to 5 nm. In this way, the system stability and the S-band splitter and the insertion loss can be comprehensively considered.
  • the bandwidth of each sub-band of the S-band splitter provided in the embodiment of the present invention can ensure that the center wavelength of the laser is not easy.
  • Deviation to the sub-wavelength range of the S-band splitter thus ensuring the stability of the communication system, on the other hand, the loss of the S-band splitter is small, thereby extending the safe distance of quantum communication, and thirdly, due to S Each subband of the band splitter has a small bandwidth, so that no more noise photons are leaked to the quantum light signal detector, thereby increasing the code rate of the quantum key.
  • Embodiments of the present invention provide a quantum communication method, including:
  • the transmitting device generates a to-be-processed optical signal and a quantum optical signal; wherein the wavelength of the quantum optical signal is in the S-band; the transmitting device couples the optical signal to be processed and the quantum optical signal to obtain the coupled optical signal; and the transmitting device transmits the coupled light through the optical fiber. signal;
  • the classical optical signal of the to-be-processed optical signal includes at least one sub-classical optical signal; when the classical optical signal includes a sub-classical optical signal, the wavelength of the sub-classical optical signal is in the C-band or the L-band;
  • the plurality of sub-classical optical signals satisfy any one of the following: the plurality of sub-classical optical signals include sub-classical optical signals having wavelengths in the C-band; and the plurality of sub-classical optical signals include wavelengths The sub-classical optical signal in the L-band; the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band.
  • the wavelength of the classical optical signal is in the L-band and/or the C-band. Since the wavelength of the quantum optical signal is in the S-band, the wavelength of the band of the classical optical signal is greater than the wavelength of the band of the quantum optical signal. Therefore, the quantum optical signal can be located.
  • the anti-Stokes scattering region because of the small scattering intensity of the anti-Stokes scattering region, can effectively reduce the influence of the Raman noise on the quantum optical signal, thereby improving the classic transmission through a fiber.
  • the wavelength of the quantum optical signal is in the S-band, and since the attenuation coefficient of the optical fiber of the S-band is small, when the quantum optical signal is transmitted in the S-band with a small insertion loss, the loss of the quantum optical signal can be reduced, thereby improving The safe distance of quantum key transmission.
  • the wavelength of the classical optical signal is in the L-band and/or C-band
  • the wavelength of the quantum optical signal is in the S-band, that is, the band of the classical optical signal and the band of the quantum optical signal are two different bands, thereby ensuring the classic
  • the distance between the wavelength of the optical signal and the wavelength of the quantum optical signal can effectively reduce the interference caused by the leakage of the classical optical signal to the quantum optical signal, and effectively reduce the FWM pair generated by the classical optical signal during transmission. Interference caused by quantum light signals.
  • the transmitting device couples the optical signal to be processed and the quantum optical signal to obtain a coupled optical signal, including the transmitting device transmitting the first sub-fiber in the optical fiber through an S-band coupler located on the optical fiber to be processed.
  • the optical signal is coupled to the quantum optical signal transmitted on the second sub-fiber in the optical fiber to obtain a coupled optical signal.
  • the S-band coupler can be a fiber coupler, or a S-band quantum optical signal and a wavelength division multiplexer of the optical signal to be processed.
  • the transmitting device generates the optical signal to be processed, and the transmitting device generates a classical optical signal, and attenuates the generated classical optical signal by using the VOA to obtain the optical signal to be processed.
  • the optical signal to be processed further includes a monitoring optical signal, wherein the monitoring optical signal is located in the L-band.
  • the transmitting device generates a to-be-processed optical signal, including the transmitting device generating the classical optical signal and the monitoring optical signal, and attenuating the generated classical optical signal through the VOA to obtain the attenuated classical optical signal; and transmitting the device through the L-band and C-band multiplexing Will decay
  • the subtracted classical optical signal is coupled with the monitored optical signal to obtain an optical signal to be processed. Since the classical optical signal is attenuated using the VOA on the transmitting device side, the EDFA commonly used in the prior art is not used, and thus the influence of the ASE noise caused by the EDFA on the QKD channel is completely eliminated.
  • the optical power requirement for the classic optical is lower for the metropolitan area network communication system.
  • the classical optical signal is attenuated by using the VOA, and the power of the classical optical signal can be completely achieved. Transmission requirements.
  • the transmitting device when there are multiple sub-classical optical signals of different wavelengths, the transmitting device generates a classical optical signal, including the transmitting device coupling the plurality of sub-classical optical signals through the first coupler or the combiner to obtain a classical optical signal.
  • the combiner meets the following conditions:
  • the plurality of sub-classical optical signals include sub-classical optical signals with wavelengths in the C-band, and the combiner is a C-band combiner; the plurality of sub-classical optical signals include sub-classical optical signals having wavelengths in the L-band, and the combiner is the L-band
  • the combiner includes a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band, and the combiner is a C-band and an L-band combiner.
  • the transmitting device when there are multiple sub-quantum optical signals of different wavelengths, the transmitting device generates the quantum optical signal, and the receiving device includes the second coupler or the S-band combiner to couple the plurality of sub-quantum optical signals to obtain the quantum optical signal.
  • Embodiments of the present invention provide a quantum communication method, including:
  • the receiving device receives the coupled optical signal sent by the transmitting device through the optical fiber; wherein the coupled optical signal includes the optical signal to be processed and the quantum optical signal; the wavelength of the quantum optical signal is in the S-band; and the receiving device determines the classic according to the coupled optical signal.
  • the coupled optical signal includes the optical signal to be processed and the quantum optical signal; the wavelength of the quantum optical signal is in the S-band; and the receiving device determines the classic according to the coupled optical signal.
  • the classical optical signal of the to-be-processed optical signal includes at least one sub-classical optical signal; when the classical optical signal includes a sub-classical optical signal, the wavelength of the sub-classical optical signal is in the C-band or the L-band;
  • the plurality of sub-classical optical signals satisfy any one of the following: the plurality of sub-classical optical signals include sub-classical optical signals having wavelengths in the C-band; and the plurality of sub-classical optical signals include wavelengths The sub-classical optical signal in the L-band; the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band.
  • the wavelength of the classical optical signal is in the L-band and/or the C-band. Since the wavelength of the quantum optical signal is in the S-band, the wavelength of the band of the classical optical signal is greater than the wavelength of the band of the quantum optical signal. Therefore, the quantum optical signal can be located.
  • the anti-Stokes scattering region because of the small scattering intensity of the anti-Stokes scattering region, can effectively reduce the influence of the Raman noise on the quantum optical signal, thereby improving the classic transmission through a fiber.
  • the wavelength of the quantum optical signal is in the S-band, and since the attenuation coefficient of the optical fiber of the S-band is small, when the quantum optical signal is transmitted in the S-band with a small insertion loss, the loss of the quantum optical signal can be reduced, thereby improving The safe distance of quantum key transmission.
  • the wavelength of the classical optical signal is in the L-band and/or C-band
  • the wavelength of the quantum optical signal is in the S-band, that is, the band of the classical optical signal and the band of the quantum optical signal are two different bands, thereby ensuring the classic
  • the distance between the wavelength of the optical signal and the wavelength of the quantum optical signal can effectively reduce the interference caused by the leakage of the classical optical signal to the quantum optical signal, and effectively reduce the FWM pair generated by the classical optical signal during transmission. Interference caused by quantum light signals.
  • the receiving device determines the classical optical signal and the quantum optical signal according to the coupled optical signal, and the receiving device separates the quantum optical signal in the coupled optical signal by using an S-band bandpass filter located on the optical fiber. a fourth sub-fiber in the optical fiber; and separating the optical signal to be processed in the coupled optical signal into a third sub-fiber in the optical fiber for processing, A classical optical signal is determined from the optical signal to be processed.
  • the S-band bandpass filter may separate the quantum optical signal in the coupled optical signal to the fourth sub-fiber in the optical fiber, and separate the optical signal to be processed in the coupled optical signal to The third sub-fiber in the optical fiber is processed, so that the classical optical signal and the quantum optical signal are transmitted through one optical fiber, and then processed separately.
  • the quantum light signal can be filtered first by the S-band band pass filter, thereby reducing the influence of noise photons.
  • the bandwidth of the S-band bandpass filter 2106 is from 0.1 nm to 5 nm.
  • the bandwidth of the S-band bandpass filter 2106 can be made 0.6 nm in practical applications.
  • the bandwidth of the S-band bandpass filter 2106 needs to cover the wavelengths of the plurality of sub-quantum optical signals, or need to cover the wavelength range of the entire S-band, optionally, the S-band bandpass The bandwidth of the filter 2106 ranges from 0.1 nm to 70 nm.
  • the receiving device determines the classical optical signal from the optical signal to be processed, including the receiving device, by using the OA, and amplifying the optical signal to be processed to obtain a classical optical signal.
  • the amplification of the classical optical signal by OA does not affect the quantum optical signal, and since the classical optical signal is lost when transmitted through the optical fiber, the classical optical signal is amplified and processed by OA, thereby improving the classic light.
  • the accuracy of signal processing is possible to improve the classical optical signal.
  • the optical signal to be processed further includes a monitoring optical signal, wherein the monitoring optical signal is located in the L-band.
  • the receiving device determines the classical optical signal from the optical signal to be processed, including the receiving device splitting the optical signal to be processed by the L-band and C-band splitter to obtain the monitoring optical signal and the split-wave optical signal; the receiving device passes the OA Amplifying the post-wavelength optical signal to obtain a classical optical signal.
  • an optical amplifying station is set in the actual transmission process, in which case the monitoring optical signal pair that can be transmitted through the first optical monitoring channel 2207 is present due to the presence of the intermediate node.
  • the transmission line is monitored to improve the security of the transmission.
  • the monitoring optical signal uses the L-band, the band distance quantum of the monitoring optical signal is monitored.
  • the optical signal has a relatively long wavelength band. Therefore, the monitoring optical signal has less influence on the noise of the quantum optical signal.
  • the receiving device determines the classical optical signal from the coupled optical signals
  • the receiving device further performs a demultiplexing process on the classical optical signals by using a splitter.
  • the plurality of sub-classical optical signals include sub-classical optical signals with wavelengths in the C-band, and the splitter is a C-band splitter; the plurality of sub-classical optical signals include sub-classical optical signals with wavelengths in the L-band, and the splitter is L-band The splitter; the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band, and the splitter is a C-band and an L-band splitter.
  • the receiving device determines the quantum optical signal from the coupled optical signals, and further includes receiving, by the S-band splitter, the wavelet optical processing of the quantum optical signals. And obtaining a plurality of sub-quantum optical signals included in the quantum optical signal.
  • a plurality of sub-classical optical signals can be separated by simultaneously receiving a plurality of sub-classical optical signals through a plurality of wavelengths. In this way, more sub-classical optical signals can be transmitted simultaneously.
  • each subband of the S-band splitter has a bandwidth ranging from 0.1 nm to 5 nm. In this way, the system stability and the S-band splitter and the insertion loss can be comprehensively considered.
  • the bandwidth of each sub-band of the S-band splitter provided in the embodiment of the present invention can ensure that the center wavelength of the laser is not easy.
  • Deviation to the sub-wavelength range of the S-band splitter thus ensuring the stability of the communication system, on the other hand, the loss of the S-band splitter is small, thereby extending the safe distance of quantum communication, and thirdly, due to S Each subband of the band splitter has a small bandwidth, so that no more noise photons are leaked to the quantum light signal detector, thereby increasing the code rate of the quantum key.
  • the transmitting device generates the optical signal to be processed and the quantum optical signal; the transmitting device will process the optical signal to be processed.
  • the signal is coupled with the quantum optical signal to obtain a coupled optical signal; the transmitting device transmits the coupled optical signal through the optical fiber.
  • the optical signal to be processed includes at least a classical optical signal; the wavelength of the quantum optical signal is in the S-band; wherein the optical signal to be processed includes at least a classical optical signal; the classical optical signal includes at least one sub-classical optical signal; and the classical optical signal includes a In the sub-classical optical signal, the wavelength of the sub-classical optical signal is in the C-band or the L-band; when the classical optical signal includes a plurality of sub-classical optical signals, the plurality of sub-classical optical signals include sub-classical optical signals having a wavelength in the C-band, or multiple sub-elements
  • the classical optical signal includes a sub-classical optical signal whose wavelength is in the L-band; or a plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band.
  • the wavelength of the classical optical signal is in the L-band and/or the C-band. Since the wavelength of the quantum optical signal is in the S-band, the wavelength of the band of the classical optical signal is greater than the wavelength of the band of the quantum optical signal. Therefore, the quantum optical signal can be located.
  • the anti-Stokes scattering region because of the small scattering intensity of the anti-Stokes scattering region, can effectively reduce the influence of the Raman noise on the quantum optical signal, thereby improving the classic transmission through a fiber.
  • the wavelength of the quantum optical signal is in the S-band, and since the attenuation coefficient of the optical fiber of the S-band is small, when the quantum optical signal is transmitted in the S-band with a small insertion loss, the loss of the quantum optical signal can be reduced, thereby improving The safe distance of quantum key transmission.
  • the wavelength of the classical optical signal is in the L-band and/or C-band
  • the wavelength of the quantum optical signal is in the S-band, that is, the band of the classical optical signal and the band of the quantum optical signal are two different bands, thereby ensuring the classic
  • the distance between the wavelength of the optical signal and the wavelength of the quantum optical signal can effectively reduce the interference caused by the leakage of the classical optical signal to the quantum optical signal, and effectively reduce the FWM pair generated by the classical optical signal during transmission. Interference caused by quantum light signals.
  • FIG. 1 is a schematic structural diagram of a system applicable to an embodiment of the present invention
  • FIG. 1a is a schematic diagram showing an attenuation coefficient corresponding to each band according to an embodiment of the present invention
  • FIG. 2 is a schematic flowchart of a quantum communication method according to an embodiment of the present invention.
  • 2a is a schematic flowchart of another quantum communication method according to an embodiment of the present invention.
  • 2b is a schematic diagram showing a correspondence relationship between noise photons and fiber lengths when quantum optical signals correspond to different wavelengths
  • 2c is a schematic structural diagram of a quantum communication system according to an embodiment of the present invention.
  • 2d is a schematic structural diagram of another quantum communication system according to an embodiment of the present invention.
  • 2 e is a schematic structural diagram of another quantum communication system according to an embodiment of the present invention.
  • 2f is a schematic structural diagram of another quantum communication system according to an embodiment of the present invention.
  • FIG. 3 is a schematic structural diagram of a sending apparatus according to an embodiment of the present disclosure.
  • FIG. 4 is a schematic structural diagram of another receiving apparatus according to an embodiment of the present invention.
  • FIG. 1 is a schematic diagram showing a system architecture applicable to an embodiment of the present invention.
  • a system architecture to which the embodiment applies includes a transmitting device 1107 and a receiving device 1108.
  • the sending device 1107 and the receiving device 1108 in the embodiment of the present invention may be located in two network devices or two user devices respectively; or the sending device 1107 is located in the network device, the receiving device 1108 is located in the user device; or the sending device is located in the user device.
  • the receiving device is located in the network device.
  • a transmitting device 1107 and a receiving device 1108 are usually disposed in the network device, and a transmitting device 1107 and a receiving device are also disposed in the network device at the other end.
  • the transmitting device 1107 in the network device at one end and the receiving device 1108 in the network device at the other end are a pair of transmitting device 1107 and receiving device 1108 in the embodiment of the present invention; receiving device 1108 in the network device at one end and another One of the network devices at one end is a transmitting device 1107 and a receiving device 1108 in another pair of embodiments of the present invention.
  • the user equipment can communicate with one or more core networks via a Radio Access Network (RAN), and the terminal equipment can refer to a User Equipment (UE), an access terminal, a subscriber unit, and a subscriber station.
  • UE User Equipment
  • the access terminal may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, or a Personal Digital Assistant (PDA).
  • the network device may be a device for communicating with the terminal device, for example, may be a base station (Base Transceiver Station, BTS for short) in the GSM system or CDMA, or a base station (NodeB, NB for short) in the WCDMA system. It may be an evolved base station (Evolutional Node B, eNB or eNodeB for short) in the LTE system, or the network device may be a relay station, an access point, an in-vehicle device, a wearable device, and a network side device in a future 5G network or a future evolution. Network devices in the PLMN network, etc.
  • BTS Base Transceiver Station
  • NodeB NodeB
  • the classical optical signal transmitter 2101 included in the transmitting device 1107 is configured to generate a classic signal
  • the quantum optical signal transmitter 2103 is configured to generate a quantum optical signal
  • the transmitting device 1107 passes the classical optical signal and the quantum optical signal through the first A coupling process of the coupling unit 1103 obtains the coupled optical signal
  • the transmitting device 1107 transmits the coupled optical signal through the optical fiber.
  • the receiving device 1108 receives the coupled optical signal through the optical fiber, and then the receiving device 1108 separates the classical optical signal in the coupled optical signal into the classical optical signal receiver 2102 through the decoupling process of the second coupling unit 1104, and couples the coupling.
  • the quantum light signals in the back light signal are separated into the quantum light signal receiver 2104 and processed accordingly.
  • the transmitting device 1107 and the receiving device 1108 respectively transmit the quantum key determined from the quantum optical signals generated by the quantum optical signal transmitter 2103 by transmitting the classical optical signal and the quantum optical signal, and the transmitting device 1107 performs the service information using the quantum key.
  • the encryption process performs further processing of the encrypted information by the classical optical signal transmitter 2101, couples it with the next quantum optical signal transmitted by the quantum optical signal transmitter 2103, and couples it to the optical fiber for transmission.
  • the classical optical signal in the coupled optical signal is separated into the classical optical signal receiver 2102, and the quantum optical signal in the coupled optical signal is separated into the quantum optical signal receiver 2104.
  • the receiving device 1108 A quantum key is determined from the quantum optical signals received by the quantum optical signal receiver 2104, and the encrypted information that has been processed in the classical optical signal received by the classical optical signal receiver 2102 is decrypted using the quantum key. Processing, and then recovering business information.
  • FIG. 1a is a schematic diagram showing an attenuation coefficient corresponding to each band according to an embodiment of the present invention, as shown in FIG.
  • the abscissa indicates the wavelength in nm
  • the ordinate indicates the fiber attenuation coefficient in decibels per kilometer (dB/km).
  • Each band corresponds to a different wavelength range, the L-band wavelength ranges from 1565 nm to 1625 nm; the C-band wavelength ranges from 1530 nm to 1565 nm; the S-band wavelength ranges from 1460 nm to 1530 nm; and the E-band wavelength ranges from 1360 nm to 1460 nm; The wavelength range of the band is from 1260 nm to 1360 nm.
  • the fiber attenuation coefficients of the S-band, C-band, and E-band are smaller than those of the other bands. Therefore, the transmission of optical signals in the S-band, C-band, and E-band is less.
  • an embodiment of the present invention provides a quantum communication scheme for realizing the transmission of a classical optical signal and a quantum optical signal in an optical fiber.
  • FIG. 2 is a schematic flow chart of a quantum communication method according to an embodiment of the present invention.
  • a quantum communication method implemented by the transmitting device 1107 side provided by the embodiment of the present invention includes:
  • Step 201 The transmitting device generates a to-be-processed optical signal and a quantum optical signal; the wavelength of the quantum optical signal is in the S-band;
  • Step 202 The transmitting device couples the optical signal to be processed and the quantum optical signal to obtain a coupled optical signal.
  • Step 203 The transmitting device sends the coupled optical signal through the optical fiber.
  • the optical signal to be processed includes at least a classical optical signal; the classical optical signal includes at least one sub-classical optical signal; when the classical optical signal includes a sub-classical optical signal, the wavelength of the sub-classical optical signal is in a C-band or an L-band;
  • the optical signal includes a plurality of sub-classical optical signals, the plurality of sub-classical optical signals satisfy any one of the following: the plurality of sub-classical optical signals include sub-classical optical signals whose wavelengths are in the C-band; and the plurality of sub-classical optical signals include the wavelengths The sub-classical optical signal of the L-band; the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band.
  • the classical optical signal when the classical optical signal includes a sub-classical optical signal, the one sub-classical optical signal is a classical optical signal; when the classical optical signal includes multiple sub-classical optical signals, the plurality of sub-classical optical signals may be combined or coupled. Thereby a classic optical signal is obtained.
  • the wavelength of the classical optical signal is in the L-band and/or the C-band. Since the wavelength of the quantum optical signal is in the S-band, the wavelength of the band of the classical optical signal is greater than the wavelength of the band of the quantum optical signal. Therefore, the quantum optical signal can be located.
  • the anti-Stokes scattering region because of the small scattering intensity of the anti-Stokes scattering region, can effectively reduce the influence of the Raman noise on the quantum optical signal, thereby improving the classic transmission through a fiber.
  • the wavelength of the quantum optical signal is in the S-band, and since the attenuation coefficient of the optical fiber of the S-band is small, when the quantum optical signal is transmitted in the S-band with a small insertion loss, the loss of the quantum optical signal can be reduced, thereby improving The safe distance of quantum key transmission.
  • the wavelength of the classical optical signal is in the L-band and/or C-band
  • the wavelength of the quantum optical signal is in the S-band, that is, the band of the classical optical signal and the band of the quantum optical signal are two different bands, thereby ensuring the classic
  • the distance between the wavelength of the optical signal and the wavelength of the quantum optical signal can effectively reduce the interference caused by the leakage of the classical optical signal to the quantum optical signal, and effectively reduce the FWM pair generated by the classical optical signal during transmission. Interference caused by quantum light signals.
  • FIG. 2a exemplarily shows a flow chart of another quantum communication method according to an embodiment of the present invention.
  • a quantum communication method implemented by the receiving device 1108 side provided by the embodiment of the present invention includes: :
  • Step 2001 the receiving device receives the coupled optical signal sent by the transmitting device through the optical fiber; wherein the coupled optical signal includes the optical signal to be processed and the quantum optical signal; the wavelength of the quantum optical signal is in the S-band;
  • Step 2002 the receiving device determines the classical optical signal and the quantum optical signal according to the coupled optical signal
  • the optical signal to be processed includes at least a classical optical signal; the classical optical signal includes at least one sub-classical optical signal; when the classical optical signal includes a sub-classical optical signal, the wavelength of the sub-classical optical signal is in a C-band or an L-band;
  • the optical signal includes a plurality of sub-classical optical signals, the plurality of sub-classical optical signals satisfy any one of the following: the plurality of sub-classical optical signals include sub-classical optical signals whose wavelengths are in the C-band; and the plurality of sub-classical optical signals include the wavelengths The sub-classical optical signal of the L-band; the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band.
  • the classical optical signal when the classical optical signal includes a sub-classical optical signal, the one sub-classical optical signal is a classical optical signal; when the classical optical signal includes multiple sub-classical optical signals, the plurality of sub-classical optical signals may be combined or coupled. Thereby a classic optical signal is obtained.
  • the wavelength of the quantum optical signal is in the S-band
  • the S-band is a band in which the attenuation coefficient of the optical fiber is small, that is, the quantum optical signal is transmitted in the S-band, compared to the quantum in the prior art.
  • the optical signal is transmitted in the O-band. Since the attenuation coefficient of the fiber in the S-band is smaller than the attenuation coefficient of the fiber in the O-band, the loss in the S-band transmission of the quantum optical signal is smaller than that in the transmission of the quantum optical signal in the O-band.
  • the quantum light signal reduces the insertion loss of the quantum light signal and improves the safety distance of the quantum key transmission.
  • spontaneous Raman scattering SRS noise is generated by inelastic scattering of pump photons and optical phonons, including Stokes and anti-Stokes scattering, and the gain range is up to 30 THz, and the peak frequency of the gain is obtained. It is about 13.2 THz and increases exponentially with increasing optical power. Usually the intensity of anti-Stokes scattering is weaker than Stokes scattering.
  • the wavelength of the quantum light signal is set larger than the wavelength of the classical light signal
  • the wavelength of the quantum light signal is located in the Stokes scattering region of the classical light signal.
  • S(L) is the Raman noise intensity caused by the classical optical power P o ;
  • P o is the power of the classic optical signal
  • ⁇ P is the fiber attenuation coefficient of the classical optical signal
  • ⁇ s is the fiber attenuation coefficient of the quantum optical signal
  • ⁇ s is the spontaneous Raman coefficient corresponding to the quantum light signal
  • L is the transmission distance
  • S(L) is the Raman noise intensity caused by the participation of multiple classical channels
  • P oi is the optical power corresponding to the i-th classical optical signal; i ranges from [1, the total number of classical optical signals];
  • ⁇ s is the fiber attenuation coefficient of the quantum optical signal
  • ⁇ si is the spontaneous Raman coefficient of the quantum light signal corresponding to the i-th classical optical signal
  • L is the transmission distance
  • P SRS is the corresponding Raman noise intensity when the wavelength bandwidth of the detector is ⁇ ;
  • S(L) is the Raman noise intensity caused by the classical optical power in equation (1) when it is P 0 .
  • ⁇ N SRS > is the average number of noise photons per time and space and polarization mode
  • P SRS is the corresponding Raman noise intensity when the wavelength bandwidth of the detector in formula (3) is ⁇ ;
  • v is the frequency of the quantum light signal
  • h is the Planck constant
  • ⁇ D is the transmission coefficient of the demultiplexer (DEMUX).
  • ⁇ N SRS > is the average number of noise photons per time and space and polarization mode
  • P 0 is the power of the classical optical signal
  • ⁇ P is the fiber attenuation coefficient of the classical optical signal
  • ⁇ s is the fiber attenuation coefficient of the quantum optical signal
  • ⁇ s is the spontaneous Raman coefficient corresponding to the quantum light signal
  • L is the transmission distance
  • ⁇ is the wavelength of the quantum light signal, and c is the speed of light
  • h is the Planck constant
  • ⁇ D is the transmission coefficient of the demultiplexer (DEMUX).
  • FIG. 2b exemplarily shows a schematic diagram of the correspondence relationship between the noise photons and the lengths of the fibers when the quantum optical signals correspond to different wavelengths. It can be seen that since the wavelength range of the L-band is 1565 nm to 1625 nm, since the wavelength range of the S-band is 1460 nm to 1530 nm, as shown in FIG.
  • the horizontal axis represents the length of the fiber in kilometers, and the vertical axis represents noise photons per nanosecond.
  • the number (shown as noise photon number / nanosecond).
  • the number of Raman noise photons generated per nanosecond in the L-band is larger than that in the S-band, for example, the noise photon of the 1470 nm wavelength is only about one tenth of that of 1630 nm. That is to say, in the actual system, when the classical optical signal uses the C-band, if the quantum optical signal operates in the L-band, the number of Raman noise photons received by the quantum optical signal is too large, and at this time, the quantum key is lowered. The successful transmission rate and the safe distance of quantum key transmission, so quantum optical signals should not work in the L-band.
  • the quantum optical signal is transmitted in the S-band.
  • the wavelength of the sub-classical optical signal is in the C-band or the L-band;
  • the classical optical signal includes a plurality of sub-classical optical signals, the plurality of sub-classical optical signals satisfy one of the following contents:
  • the plurality of sub-classical optical signals include sub-classical optical signals whose wavelengths are in the C-band; the plurality of sub-classical optical signals include sub-classical optical signals whose wavelengths are in the L-band; and the plurality of sub-classical optical signals include sub-classical optical signals whose wavelengths are in the C-band And sub-classical optical signals with wavelengths in the L-band.
  • the classical optical signal includes a sub-classical optical signal
  • the one sub-classical optical signal is a classical optical signal
  • the classical optical signal includes multiple sub-classical optical signals
  • the plurality of sub-classical optical signals may be combined or coupled. Thereby a classic optical signal is obtained.
  • the wavelength of the sub-classical optical signal included in the classical optical signal is in the range of 1530 nm to 1565 nm in the C-band; or the wavelength of the sub-classical optical signal included in the classical optical signal is in the wavelength range of 1565 nm in the L-band to Within 1625 nm; or the sub-classical optical signal included in the classical optical signal has wavelengths in the L-band and C-band wavelengths ranging from 1530 nm to 1625 nm.
  • the wavelength of the classical optical signal can be made larger than the wavelength of the quantum optical signal, so that the quantum optical signal is located in the anti-Stokes scattering region, thereby reducing the number of Raman noise photons corresponding to the wavelength of the quantum optical signal, that is, the phase.
  • the wavelength of the quantum optical signal is in the S-band, and the number of Raman noise photons received by the quantum optical signal is less than ten times, that is, the present invention.
  • the wavelength of the classical optical signal is in the C-band
  • the wavelength of the quantum optical signal is in the S-band
  • the Raman noise resistance generated by the quantum optical signal on the C-band is compared with the scheme of setting the wavelength band of the quantum optical signal to the L-band.
  • the ability has increased tenfold, which reduces the bit error rate of the system and further improves the successful transmission rate of the quantum key.
  • the wavelength of the simultaneously selected quantum optical signal is such that the gain peak frequency offset of the Stokes and anti-Stokes scattering is avoided (eg, 13.2 THz).
  • the wavelength of the quantum optical signal is in the S-band (for example, 1470 nm), which is far from the wavelength of the C-band and L-band used by the classical optical signal, that is, the wavelength band of the quantum optical signal and the band of the classical optical signal are located in different bands. Therefore, the quantum light signal is well protected from FWM and amplified spontaneous emission (Amplified Spontaneous Emission, Referred to as ASE), the influence of noise reduces the bit error rate of the system and further improves the successful transmission rate of the quantum key.
  • ASE amplified Spontaneous Emission
  • the embodiment of the present invention not only reduces the loss of the quantum optical signal when realizing the homogenous fiber mixed transmission of the classical optical signal and the quantum optical signal, but also reduces the noise photon caused by the classical optical signal.
  • the degree of influence on the quantum light signal thereby further increasing the safe distance of quantum key transmission.
  • FIG. 2c is a schematic structural diagram of a quantum communication system according to an embodiment of the present invention.
  • the transmitting device 1107 includes an S-band coupler 2105
  • the receiving device 1108 includes an S-band bandpass filter 2106.
  • the S-band coupler 2105 can be the first coupling unit 1103 in FIG.
  • the S-band bandpass filter 2106 can be the second coupling unit 1104 of FIG.
  • the transmitting device 1107 couples the optical signal to be processed and the quantum optical signal to obtain a coupled optical signal, including:
  • the transmitting device 1107 transmits the optical signal to be processed transmitted on the first sub-fiber 2107 in the optical fiber 2109 and the quantum optical signal transmitted on the second sub-fiber 2108 in the optical fiber 2109 through the S-band coupler 2105 located on the optical fiber 2109. Coupling, the coupled optical signal is obtained.
  • the S-band coupler 2105 can couple the optical signal to be processed transmitted on the first sub-fiber 2107 and the S-band quantum optical signal transmitted on the second sub-fiber 2108 in the optical fiber 2109 on the one hand, thereby Realize the transmission of classical optical signals and S-band quantum optical signals through an optical fiber.
  • the S-band coupler can be a fiber coupler, or a S-band quantum optical signal and a wavelength division multiplexer of the optical signal to be processed.
  • the essence of reducing the influence of noise photons on the quantum light signal is to reduce the number of noise photons that eventually leak to the quantum light signal detector. Therefore, the band around the quantum light signal can be effectively filtered by the S-band bandpass filter 2106. The noise photons, thereby reducing the number of noise photons that eventually reach the quantum light signal detector.
  • the receiving device 1108 determines the classic optical signal and the quantum optical signal according to the coupled optical signal, including:
  • the receiving device 1108 separates the quantum optical signal in the coupled optical signal into the fourth sub-fiber 2111 in the optical fiber 2109 through the S-band bandpass filter 2106 located on the optical fiber 2109; and the to-be-processed in the coupled optical signal
  • the optical signal is separated into a third sub-fiber 2110 in the optical fiber 2109 for processing, and a classical optical signal is determined from the optical signal to be processed.
  • the S-band bandpass filter 2106 can separate the quantum optical signal in the coupled optical signal to the fourth sub-fiber 2111 in the optical fiber 2109, and the light to be processed in the coupled optical signal.
  • the signal is separated into the third sub-fiber 2110 in the optical fiber 2109 for processing, so that the classical optical signal and the quantum optical signal are transmitted through one optical fiber, and then processed separately.
  • the quantum light signal can be filtered first by the S-band bandpass filter 2106, thereby reducing the influence of noise photons.
  • the S-band bandpass filter 2106 when used to separate the S-band quantum optical signal and the classical optical signal output by the quantum optical signal transmitter 2103, it is necessary to balance the filtering bandwidth of the S-band bandpass filter 2106 with the output quantum light.
  • the laser stability of the signal Due to various unstable factors, such as temperature changes, atmospheric changes, mechanical vibrations, changes in magnetic fields, the drift of the laser frequency of the actual quantum light signal is significant.
  • the S-band bandpass filter 2106 in the embodiment of the present invention is not used, Instead, an ultra-narrowband bandpass filter is used, and the center wavelength of the quantum optical signal is easily deviated outside the filtering range of the ultra-narrowband bandpass filter, thereby causing the ultra-narrowband bandpass filter to filter the quantum optical signal. Therefore, the quantum optical signal cannot be transmitted, and at the same time, the ultra-narrow band pass filter introduces a large loss. However, on the other hand, if the bandwidth of the S-band bandpass filter 2106 is large, more noise photons are leaked to the quantum light signal detector, thereby affecting the rate of the final quantum key.
  • the bandwidth of the S-band bandpass filter 2106 is from 0.1 nm to 5 nm.
  • the bandwidth of the S-band bandpass filter 2106 can be made 0.6 nm in practical applications.
  • the bandwidth of the S-band bandpass filter 2106 needs to cover the wavelengths of the plurality of sub-quantum optical signals, or need to cover the wavelength range of the entire S-band, optionally, the S-band bandpass filter 2106 The bandwidth ranges from 0.1 nm to 70 nm.
  • the bandwidth of the S-band bandpass filter 2106 provided in the embodiment of the present invention can ensure that the center wavelength of the laser is not easy. Deviating to the filtering range of the S-band bandpass filter 2106, thereby ensuring the stability of the communication system, on the other hand, the loss of the S-band bandpass filter 2106 is small, thereby extending the safety distance of the quantum communication, and the third Since the bandwidth of the S-band bandpass filter 2106 is small, no more noise photons are leaked to the quantum light signal detector, thereby increasing the code rate of the quantum key.
  • the classical optical signal and the quantum optical signal are located in different wavelength bands and the distance is long, the performance of the S-band band-pass filter 2106 does not need to be high, and the noise photon of the classical optical signal to the quantum optical signal can be filtered. Purpose, thereby reducing the cost of the quantum communication system.
  • FIG. 2d exemplarily shows a schematic structural diagram of another quantum communication system according to an embodiment of the present invention.
  • the transmitting device 1107 generates an optical signal to be processed, including: the transmitting device 1107 generates a classical optical signal, and attenuates the generated classical optical signal through the VOA 2205 to obtain an optical signal to be processed.
  • the classical optical signal is attenuated using the VOA 2205 on the transmitting device 1107 side, the EDFA commonly used in the prior art is not used, and thus the influence of the ASE noise caused by the EDFA on the QKD channel is completely eliminated.
  • the optical power requirement for the classic optical is low for the metropolitan area network communication system.
  • the classical optical signal is attenuated by using the VOA2205, and the power of the classical optical signal can be completely achieved. Transmission requirements.
  • the receiving device 1108 determines the classic optical signal from the optical signal to be processed, and the receiving device 1108 amplifies the optical signal to be processed through the OA2305 to obtain a classical optical signal. Specifically, after the receiving device 1108 separates the classical optical signal from the quantum optical signal, the classical optical signal is amplified by the OA without affecting the quantum optical signal, and the classical optical signal is lost when transmitted through the optical fiber. Therefore, the classical optical signal is amplified and processed by OA, which can improve the accuracy of the classical optical signal processing.
  • FIG. 2e is a schematic structural diagram of another quantum communication system according to an embodiment of the present invention.
  • the classical optical signal transmitter 2101 couples the monitoring optical signal generated by the first optical monitoring channel 2207 of the classical optical signal through the L-band and C-band combiner 2206, and couples to the first sub-fiber 2107 for transmission.
  • the demultiplexer and the combiner in the embodiment of the present invention are based on a wavelength division multiplexing system. That is, in the embodiment of the present invention, a quantum optical signal transmitter 2103 is superimposed on the existing WDM system (main channel + monitoring channel).
  • the optical signal to be processed further includes a monitoring optical signal, where the monitoring optical signal is located in the L-band;
  • the sending device 1107 generates a light signal to be processed, including:
  • the transmitting device 1107 generates a classic optical signal and a monitoring optical signal, and attenuates the generated classical optical signal by VOA to obtain an attenuated classical optical signal;
  • the transmitting device 1107 couples the attenuated classical optical signal and the monitoring optical signal through the L-band and C-band combiner 2206 to obtain an optical signal to be processed.
  • an optical amplifying station is set in the actual transmission process, in which case the monitoring optical signal pair that can be transmitted through the first optical monitoring channel 2207 is present due to the presence of the intermediate node.
  • the transmission line is monitored to improve the security of the transmission.
  • it is better compatible with the layout of the monitoring channel in the prior art.
  • the monitoring optical signal uses the L-band, the band distance quantum of the monitoring optical signal is monitored. Band of optical signal Farther, therefore, the monitoring optical signal has less influence on the noise of the quantum optical signal.
  • the optical signal to be processed further includes a monitoring optical signal, wherein the monitoring optical signal is located in the L-band;
  • the receiving device 1108 determines the classic optical signal from the optical signal to be processed, including:
  • the receiving device 1108 divides the optical signal to be processed by the L-band and C-band splitter 2306 to obtain a monitor optical signal and a split-wave optical signal; the receiving device 1108 amplifies the split-wave optical signal through the OA to obtain a classic Optical signal.
  • an optical amplifying station is set in the actual transmission process, in which case the monitoring optical signal that can be received through the second optical monitoring channel 2307 is present due to the presence of the intermediate node.
  • Monitoring the transmission line improves the security of the transmission on the one hand, and is better compatible with the layout of the monitoring channel in the prior art on the other hand.
  • the monitoring optical signal uses the L-band, the band distance of the monitored optical signal is monitored.
  • the quantum optical signal has a relatively long wavelength band. Therefore, the monitoring optical signal has less influence on the noise of the quantum optical signal.
  • the successful separation of the classical optical signal and the monitoring optical signal is realized, so that they can be separately processed to realize their respective functions.
  • FIG. 2f is a schematic structural diagram of another quantum communication system according to an embodiment of the present invention.
  • the transmitting device 1107 when there are a plurality of sub-classical optical signals of different wavelengths on the transmitting device 1107 side, the transmitting device 1107 generates a classical optical signal, including: the transmitting device 1107 passes the first coupler or the combiner 2204 The plurality of sub-classical optical signals are coupled to obtain a classical optical signal; wherein the combiner 2204 satisfies the following conditions:
  • the plurality of sub-classical optical signals include sub-classical optical signals having a wavelength in the C-band, and the combiner 2204 is a C-band combiner;
  • the plurality of sub-classical optical signals include sub-classical optical signals having wavelengths in the L-band, and the combiner 2204 is an L-band combiner;
  • the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band, and the combiner 2204 is a C-band and L-band combiner.
  • the transmitting device 1107 couples the plurality of sub-classical optical signals through the first coupler or the combiner 2204 to obtain a classical optical signal.
  • the communication system can be simplified, the operation is facilitated, and the insertion loss in the system is further reduced.
  • a plurality of sub-classical optical signals can be simultaneously transmitted through a plurality of wavelengths, such as sub-classical optical signal 2201, sub-classical optical signal 2202, sub-classical optical signal 2203, and the like in FIG. 2f.
  • a plurality of sub-classical optical signals are coupled by a first coupler or combiner 2204 and transmitted over an optical fiber. In this way, more sub-classical optical signals can be transmitted simultaneously.
  • the classic information in the embodiment of the present invention may be information of any one or any of the negotiation information, the service information, and the synchronization clock signal, and each of the sub-classical optical signals may also be any of the negotiation information, the service information, and the synchronous clock signal.
  • One or more items of information may be negotiation information for causing a receiving device and a transmitting device to negotiate a quantum key, or service information encrypted by a quantum key.
  • the method further includes: the receiving device 1108 passes through the splitter 2304, The classical optical signal is subjected to partial processing to obtain a plurality of sub-classical optical signals included in the classical optical signal; wherein the splitter demultiplexer satisfies the following conditions:
  • the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band, and the demultiplexer demultiplexer is a C-band demultiplexer;
  • the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the L-band, and the splitter demultiplexer is an L-band splitter;
  • the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band, and the demultiplexer demultiplexer is a C-band and an L-band demultiplexer.
  • multiple sub-classical optical signals can be simultaneously received through multiple wavelengths, such as sub-classical optical signal 2301, sub-classical optical signal 2302, sub-classical optical signal 2303, and the like in FIG. 2f.
  • a plurality of sub-classical optical signals are separated by a splitter 2304. In this way, more sub-classical optical signals can be transmitted simultaneously.
  • the transmitting device 1107 when there are a plurality of sub-quantum optical signals of different wavelengths on the transmitting device 1107 side: the transmitting device 1107 generates a quantum optical signal, including: the receiving device 1108 passes through the second coupler or the S-band The waver 2404 couples the plurality of sub-quantum optical signals to obtain a quantum optical signal.
  • the receiving device 1108 couples the plurality of sub-quantum optical signals through the second coupler to obtain a quantum optical signal.
  • the quantum light signal may be an optical signal with a quantum state as an information carrier, such as a set of random numbers, and the set of random numbers may be used to generate a final quantum key.
  • Each sub-quantum optical signal in the embodiment of the present invention may be an optical signal in which the quantum state is an information carrier.
  • a sub-quantum optical signal may be a set of random numbers, and the set of random numbers may be used to generate a final quantum key.
  • the quantum optical signal and the transmitted optical signal are mixed and transmitted in one optical fiber, the quantum optical signal is inevitably affected by certain noise and the quantum key generation rate is lowered, in order to reduce the quantum key generation rate. Further, the quantum key generation rate is further improved.
  • multiple sub-quantum optical signals are simultaneously transmitted through multiple wavelengths, thereby increasing the transmission rate of the sub-quantum optical signals, thereby increasing the generation rate of the quantum key, thereby enabling More classical optical signals are encrypted, which improves the communication efficiency of quantum communication.
  • the receiving device 1108 further includes: receiving device 1108
  • the quantum light signal is subjected to demultiplexing processing by the S-band demultiplexer 2504 to obtain a plurality of sub-quantum optical signals included in the quantum optical signal.
  • the quantum optical signal and the transmitted optical signal are mixed and transmitted in one optical fiber, the quantum optical signal is inevitably affected by certain noise and the quantum key generation rate is lowered, in order to reduce the quantum key generation rate. Further, the quantum key generation rate is further improved.
  • multiple sub-quantum optical signals are simultaneously transmitted through multiple wavelengths, thereby increasing the transmission rate of the sub-quantum optical signals, thereby increasing the generation rate of the quantum key, thereby enabling More classical optical signals are encrypted, which improves the communication efficiency of quantum communication.
  • the S-band demultiplexer 2504 when the S-band demultiplexer 2504 is used to demultiplex the quantum signal, it is necessary to balance the bandwidth of each sub-band of the S-band demultiplexer 2504 with the laser stability of the output quantum optical signal. Due to various unstable factors, such as temperature changes, atmospheric changes, mechanical vibrations, changes in magnetic fields, the drift of the laser frequency of the actual quantum light signal is significant, if the S-band splitter 2504 in the embodiment of the present invention is not used, The ultra-narrowband bandpass filter is used, and the center wavelength of the quantum optical signal is easily deviated from the filtering range of the ultra-narrowband bandpass filter, thereby causing the ultra-narrowband bandpass filter to filter the quantum optical signal.
  • each subband of the S-band splitter 2504 has a bandwidth ranging from 0.1 nm to 5 nm.
  • the bandwidth of each sub-band of the S-band splitter 2504 can be made 0.6 nm in practical applications. In this way, the system stability and the S-band demultiplexer 2504 and the insertion loss can be comprehensively considered.
  • the bandwidth of each sub-band of the S-band demultiplexer 2504 provided in the embodiment of the present invention can ensure that the center wavelength of the laser is not Will easily deviate to the S-band splitter 2504 Outside the wavelength range, thus ensuring the stability of the communication system, on the other hand, the loss of the S-band splitter 2504 is small, thereby extending the safety distance of the quantum communication, and third, due to the S-band splitter 2504 The bandwidth of each sub-band is small, so that no more noise photons are leaked to the quantum light signal detector, thereby increasing the code rate of the quantum key.
  • a plurality of sub-classical optical signals are coupled by a first coupler or combiner 2204 to obtain a classical optical signal, and then the classical optical signal is attenuated by the tunable optical attenuator 2205 to obtain an attenuated classical optical signal.
  • the first optical monitoring channel 2207 generates a monitoring optical signal, and the attenuated classical optical signal and the monitoring optical signal are coupled by the L-band and C-band combiner 2206 to obtain an optical signal to be processed, and transmitted on the first sub-fiber 2107. Processing optical signals.
  • the plurality of sub-quantum optical signals are coupled by a second coupler or S-band combiner 2404 to obtain a quantum optical signal that is transmitted over the second sub-fiber 2108.
  • the transmitting device 1107 transmits the optical signal to be processed transmitted on the first sub-fiber 2107 in the optical fiber 2109 and the quantum optical signal transmitted on the second sub-fiber 2108 in the optical fiber 2109 through the S-band coupler 2105 located on the optical fiber 2109. Coupling, the coupled optical signal is obtained.
  • the transmitting device 1107 transmits the coupled optical signal through the optical fiber.
  • the receiving device 1108 receives the coupled optical signal through the optical fiber.
  • the receiving device 1108 separates the quantum optical signal in the coupled optical signal into the fourth sub-fiber 2111 in the optical fiber 2109 through the S-band bandpass filter 2106 located on the optical fiber 2109; and the to-be-processed in the coupled optical signal
  • the optical signal is separated into a third sub-fiber 2110 in fiber 2109 for processing.
  • the receiving device 1108 demultiplexes the optical signal to be processed by the L-band and C-band demultiplexer 2306 to obtain a monitor optical signal and a post-wavelength optical signal.
  • the receiving device 1108 amplifies the post-wavelength optical signal through the OA to obtain a classical optical signal.
  • the receiving device 1108 performs a demultiplexing process on the quantum optical signal by the S-band demultiplexer 2504 to obtain a plurality of sub-quantum optical signals included in the quantum optical signal.
  • the receiving device 1108 and the transmitting device 1107 further determine the quantum key according to the received classical optical signal, the quantum optical signal, and the monitoring optical signal, so that the transmitting device 1107 encrypts the service information using the quantum key, and encrypts the service.
  • the information is transmitted to the receiving device 1108, and the receiving device 1108 decrypts the service information using the determined quantum key to obtain the service information.
  • the wavelength of the classical optical signal is in the L-band and/or the C-band
  • the wavelength of the quantum optical signal is in the S-band
  • the wavelength of the band of the classical optical signal is larger than the wavelength of the band of the quantum optical signal, therefore,
  • the quantum light signal can be located in the anti-Stokes scattering region, and because the scattering intensity of the anti-Stokes scattering region is small, the degree of influence of the Raman noise on the quantum optical signal can be effectively reduced, thereby improving the pass-through
  • the quality of the quantum optical signal when the root fiber mixes the classical optical signal and the quantum optical signal.
  • FIG. 3 is a schematic structural diagram of a transmitting apparatus 1107 for quantum communication provided by an embodiment of the present invention.
  • an embodiment of the present invention provides a transmitting apparatus 1107 for quantum communication, as shown in FIG. 3,
  • the transmitting device 1107 includes a classic optical signal transmitter 2101, a quantum optical signal transmitter 2103, a first coupling unit 1103, and a transmitting unit 3101:
  • a classic optical signal transmitter 2101 for generating an optical signal to be processed
  • a quantum optical signal transmitter 2103 configured to generate a quantum optical signal; wherein the optical signal to be processed includes at least a classical optical signal; and the wavelength of the quantum optical signal is in an S-band;
  • a first coupling unit 1103, configured to couple the optical signal to be processed and the quantum optical signal to obtain a coupled optical signal
  • the sending unit 3101 is configured to send the coupled optical signal through the optical fiber.
  • the wavelength of the classical optical signal is in any of the following: C-band; L-band; L-band and C-band.
  • the first coupling unit 1103 is specifically configured to:
  • the S-band coupler 2105 located on the optical fiber 2109 couples the optical signal to be processed transmitted on the first sub-fiber 2107 in the optical fiber 2109 with the quantum optical signal transmitted on the second sub-fiber 2108 in the optical fiber 2109.
  • the coupled light signal is
  • the classic optical signal transmitter 2101 is specifically configured to:
  • the generated classical optical signal is attenuated to obtain an optical signal to be processed.
  • the optical signal to be processed further includes a monitoring optical signal, where the monitoring optical signal is located in the L-band;
  • the classic optical signal transmitter 2101 is specifically used for:
  • the generated classical optical signal is attenuated to obtain an attenuated classical optical signal
  • the attenuated classical optical signal and the monitoring optical signal are coupled by the L-band and C-band combiner 2206 to obtain an optical signal to be processed.
  • the classic optical signal transmitter 2101 is specifically used for:
  • a plurality of sub-classical optical signals are coupled by a first coupler or combiner 2204 to obtain a classical optical signal; wherein the combiner satisfies the following conditions:
  • the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band, and the combiner is a C-band combiner;
  • the plurality of sub-classical optical signals include sub-classical optical signals having wavelengths in the L-band, and the combiner is an L-band combiner;
  • the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band and a sub-classical optical signal having a wavelength in the L-band, and the combiner is a C-band and an L-band combiner.
  • the quantum optical signal transmitter 2103 is specifically configured to:
  • a plurality of sub-quantum optical signals are coupled by a second coupler or S-band combiner 2404 to obtain a quantum optical signal.
  • the wavelength of the classical optical signal is in the L-band and/or the C-band, and the wavelength of the quantum optical signal is in the S-band
  • the wavelength of the band of the classical optical signal is greater than that of the quantum optical signal.
  • the wavelength of the band therefore, the quantum light signal can be located in the anti-Stokes scattering region, and because the scattering intensity of the anti-Stokes scattering region is small, the degree of influence of the Raman noise on the quantum optical signal can be effectively reduced. , thereby improving the quality of the quantum optical signal when mixing the classical optical signal and the quantum optical signal through one optical fiber.
  • FIG. 4 is a schematic structural diagram of a receiving apparatus 1108 for quantum communication provided by an embodiment of the present invention.
  • an embodiment of the present invention provides a receiving apparatus 1108 for quantum communication.
  • the receiving apparatus 1108 includes a classical optical signal receiver 2102, a quantum optical signal receiver 2104, and a second coupling unit 1104.
  • the receiving unit 4101 is configured to receive, by the optical fiber, the coupled optical signal sent by the transmitting device 1107; wherein the coupled optical signal includes a to-be-processed optical signal and a quantum optical signal; the optical signal to be processed includes at least a classical optical signal; and the quantum optical signal The wavelength is in the S band;
  • a second coupling unit 1104 configured to determine a to-be-processed optical signal and a quantum optical signal from the coupled optical signal
  • the classical optical signal receiver 2102 is configured to receive the optical signal to be processed output by the second coupling unit 1104, and determine a classical optical signal from the optical signal to be processed;
  • the quantum optical signal receiver 2104 is configured to receive and process the quantum optical signal output by the second coupling unit 1104.
  • the wavelength of the classical optical signal is in any of the following: C-band; L-band; L-band and C-band.
  • the second coupling unit 1104 is specifically configured to:
  • the third sub-fiber 2110 in the optical fiber 2109 is processed to determine a classical optical signal from the optical signal to be processed.
  • the bandwidth of the S-band bandpass filter 2106 ranges from 0.1 nm to 70 nm.
  • the classic optical signal receiver 2102 is specifically configured to:
  • the optical signal to be processed is amplified to obtain a classical optical signal.
  • the optical signal to be processed further includes a monitoring optical signal, wherein the monitoring optical signal is located in the L-band;
  • the classic optical signal receiver 2102 is specifically configured to:
  • the L-band and C-band splitter 2306 splits the optical signal to be processed to obtain a monitor optical signal and a split-wave optical signal;
  • the post-wavelength optical signal is amplified to obtain a classical optical signal.
  • the classic optical signal receiver 2102 is also used to:
  • the classical optical signal is subjected to demultiplexing processing by the demultiplexer 2304 to obtain a plurality of sub-classical optical signals included in the classical optical signal; wherein the demultiplexer satisfies the following conditions:
  • the plurality of sub-classical optical signals include a sub-classical optical signal having a wavelength in the C-band, and the splitter is a C-band splitter;
  • the plurality of sub-classical optical signals include sub-classical optical signals having wavelengths in the L-band, and the splitter is an L-band splitter;
  • the plurality of sub-classical optical signals include sub-classical optical signals with wavelengths in the C-band and sub-classical optical signals with wavelengths in the L-band, and the demultiplexers are C-band and L-band splitters.
  • the quantum optical signal receiver 2104 is further configured to:
  • the quantum light signal is subjected to demultiplexing processing by the S-band demultiplexer 2504 to obtain a plurality of sub-quantum optical signals included in the quantum optical signal.
  • each subband of the S-band splitter has a bandwidth ranging from 0.1 nm to 5 nm.
  • the quantum optical signal since the wavelength of the classical optical signal is in the L-band and/or C-band, the quantum optical signal The wavelength of the wavelength of the classical optical signal is greater than the wavelength of the band of the quantum optical signal. Therefore, the quantum optical signal can be located in the anti-Stokes scattering region and the scattering intensity of the anti-Stokes scattering region. It is small, so it can effectively reduce the influence of the Raman noise on the quantum optical signal, thereby improving the quality of the quantum optical signal when the classical optical signal and the quantum optical signal are mixed and transmitted through one optical fiber.
  • embodiments of the present invention can be provided as a method, or a computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or a combination of software and hardware. Moreover, the invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.
  • a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) including computer usable program code.
  • the computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture comprising the instruction device.
  • the apparatus implements the functions specified in one or more blocks of a flow or a flow and/or block diagram of the flowchart.
  • These computer program instructions can also be loaded onto a computer or other programmable data processing device such that a series of operational steps are performed on a computer or other programmable device to produce computer-implemented processing for execution on a computer or other programmable device.
  • the instructions provide steps for implementing the functions specified in one or more of the flow or in a block or blocks of a flow diagram.

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Abstract

本发明实施例涉及通信技术领域，尤其涉及一种量子通信方法和相关装置，用于在将经典光信号和量子光信号通过一根光纤进行混传时，降低量子光信号受到的拉曼噪声的影响，本发明实施例中，发送装置生成待处理光信号和量子光信号；待处理光信号中至少包括经典光信号；发送装置将待处理光信号和量子光信号耦合，得到并发送耦合后光信号。由于经典光信号的波长处于L波段和/或C波段，量子光信号的波长处于S波段，因此经典光信号的波段的波长大于所述量子光信号的波段的波长，因此，量子光信号可位于反斯托克斯散射区，可有效减少量子光信号所受到的拉曼噪声的影响程度。

Description

一种量子通信方法和相关装置
本申请要求在2016年06月02日提交中国专利局、申请号为201610388547.2、发明名称为“一种量子通信方法和相关装置”的中国专利申请的优先权，其全部内容通过引用结合在本申请中。
技术领域
本发明实施例涉及通信技术领域，尤其涉及一种量子通信方法和相关装置。
背景技术
为了有效解决信息安全问题，量子密钥分配(Quantum Key Distribution，简称QKD)技术应运而生，目前正在走向市场实用化。
对于一个单向的QKD系统而言，其实现方式是通过在发送装置对量子光信号的量子态上编码一组随机数，在经过量子信道传输后被接收装置的接收机检测，然后发送装置和接收装置通过经典信道的数据比对和协商等一系列处理过程，最终使得双方共享一组安全的随机数密钥。典型的QKD系统中，用于发送装置和接收装置通信的光纤只承载量子信号，这有利于量子信号的探测，因为此时没有其它光信号引入额外噪声的影响。然而，未来量子通信必然向着网络化和全球化的方向发展。如今，各城域网发展过程中，光纤网络的铺设是基础，不可能将原有的光纤网络推翻，铺设新的量子网络，所以，只能在原有光纤的网络基础上，采用波分复用(Wavelength Division Multiplexing，简称WDM)技术集成组成量子-经典混合光网络，即，需要采用WDM技术，在一根光纤中同时传输量子光信号和经典光信号。
WDM是将两种或多种不同波长的光载波信号(携带各种信息)在发送装置经复用器(Multiplexer)(亦称合波器)汇合在一起，并耦合到光线路的同一根光纤中进行传输的技术；在接收装置，经解复用器(Demultiplexer)(亦称分波器或称去复用器)将各种波长的光载波分离，然后由光接收机作进一步处理以恢复原信号。
现有技术中，可以用于传输光载波信号的有多个波段，比如L波段、C波段、S波段、E波段和O波段。每个波段对应不同的波长范围，L波段的波长范围为1565纳米(nm)至1625nm；C波段的波长范围为1530nm至1565nm；S波段的波长范围为1460nm至1530nm；E波段的波长范围为1360nm至1460nm；O波段的波长范围为1260nm至1360nm。
一种实现经典信号和量子信号在同一根光纤中混传的解决方案为，基于WDM技术将经典光信号在C波段传输，将量子光信号在L波段传输。但是，在光纤中，由于拉曼噪声是泵浦光子与光学声子发生非弹性散射产生，产生的散射光子波长小于或大于泵浦光，分别对应于反斯托克斯散射区和斯托克斯散射区。且由于斯托克斯散射区的散射强度大于反斯托克斯散射区，因此，将量子光信号放置于波长较长的L波段时，量子光信号主要受斯托克斯散射区的影响，此时量子光信号受到的拉曼噪声的影响较大。
综上，亟需一种量子通信方法和相关装置，用于在将经典光信号和量子光信号通过一根光纤进行混传时，降低量子光信号受到的拉曼噪声的影响。
发明内容
本发明实施例提供一种量子通信方法和相关装置，用于在将经典光信号和量子光信号 通过一根光纤进行混传时，降低量子光信号受到的拉曼噪声的影响。
本发明实施例提供一种用于量子通信的发送装置，包括：
经典光信号发送机，用于生成待处理光信号；
量子光信号发送机，用于生成量子光信号；量子光信号的波长处于S波段；
第一耦合单元，用于将待处理光信号和量子光信号耦合，得到耦合后光信号；
发送单元，用于通过光纤发送耦合后光信号；
其中，待处理光信号中至少包括经典光信号；的经典光信号包括至少一个子经典光信号；经典光信号包括一个子经典光信号时，子经典光信号的波长处于C波段或L波段；
经典光信号包括多个子经典光信号时，多个子经典光信号满足以下内容中的任一项：多个子经典光信号中包括波长处于C波段的子经典光信号；多个子经典光信号中包括波长处于L波段的子经典光信号；多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。
可见，经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，因此经典光信号的波段的波长大于量子光信号的波段的波长，因此，量子光信号可位于反斯托克斯散射区，又由于反斯托克斯散射区的散射强度较小，因此可有效减少量子光信号所受到的拉曼噪声的影响程度，从而提高了通过一根光纤混传经典光信号和量子光信号时量子光信号的质量。
进一步，量子光信号的波长处于S波段，且由于S波段的光纤衰减系数较小，因此当将量子光信号在插损较小的S波段进行传输时，可减轻量子光信号的损耗，从而提高了量子密钥传输的安全距离。
进一步，由于经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，即经典光信号的波段与量子光信号的波段为两个不同的波段，从而保证了经典光信号的波长和量子光信号的波长之间的距离，如此，可有效降低由于经典光信号的泄露对量子光信号所造成的干扰，以及有效降低经典光信号在传输过程中所产生的四波混频(Four-Wave Mixing，简称FWM)对量子光信号所造成的干扰。
可选地，第一耦合单元，具体用于通过位于光纤上的S波段耦合器，将在光纤中的第一子光纤上传输的待处理光信号和在光纤中的第二子光纤上传输的量子光信号耦合，得到耦合后光信号。S波段耦合器可以是光纤耦合器，或者S波段量子光信号和待处理光信号的波分复用器。
可选地，经典光信号发送机，具体用于生成经典光信号，并通过可调光衰减器(Variable Optical Attenuator，简称VOA)，对生成的经典光信号进行衰减，得到待处理光信号。由于在发送装置侧，使用VOA对经典光信号进行衰减，并不使用现有技术中常用的EDFA，如此，则彻底消除EDFA所引起的ASE噪声对QKD信道的影响。另一方面，由于光纤传输损耗较低，因此对于城域网通讯系统，对经典光的光功率要求较低，此时，使用VOA对经典光信号进行衰减，完全可以使经典光信号的功率达到传输要求。
可选地，待处理光信号还包括监控光信号，其中，监控光信号位于L波段。经典光信号发送机，具体用于生成经典光信号和监控光信号，并通过VOA，对生成的经典光信号进行衰减，得到衰减后经典光信号；通过L波段和C波段合波器将衰减后的经典光信号和监控光信号耦合，得到待处理光信号。
如此，当用较长距离的城际量子通信时，在实际传输过程中设置光放大站点，在这种 情况下由于存在中间节点，因此可通过第一光监控信道2207所发送的监控光信号对传输线路进行监控，一方面提高了传输的安全性，另一方面更好的兼容了现有技术中的监控信道的布局，第三，由于监控光信号使用L波段，监控光信号的波段距离量子光信号的波段较远，因此，监控光信号对量子光信号的噪声影响较小。
可选地，存在多个不同波长的子经典光信号时，经典光信号发送机，具体用于通过第一耦合器或合波器，将多个子经典光信号耦合，得到经典光信号。其中，合波器满足以下条件：
多个子经典光信号中包括波长处于C波段的子经典光信号，合波器为C波段合波器；多个子经典光信号中包括波长处于L波段的子经典光信号，合波器为L波段合波器；多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，合波器为C波段和L波段合波器。
通过第一耦合器或合波器，将多个子经典光信号耦合，得到经典光信号。如此，可更加简化通信系统，便于操作，且进一步降低系统中的插损。
可选地，存在多个不同波长的子量子光信号时，量子光信号发送机，具体用于通过第二耦合器或S波段合波器，将多个子量子光信号耦合，得到量子光信号。由于量子光信号和发送光信号在一根光纤中进行混传，相比单独传输量子光信号的方案，不可避免的会使量子光信号受到一定的噪声影响，降低量子密钥的生成率，为了进一步提高量子密钥生成率，本发明实施例中通过多个波长同时传输多个子量子光信号，从而增大了子量子光信号的传输率，从而加大了量子密钥的生成速率，从而可对更多的经典光信号进行加密，从而提高了量子通信的通信效率。
本发明实施例提供一种用于量子通信的接收装置，包括：
接收单元，用于通过光纤接收发送装置发送的耦合后光信号；其中，耦合后光信号包括待处理光信号和量子光信号；量子光信号的波长处于S波段；
第二耦合单元，用于从耦合后光信号中确定出待处理光信号和量子光信号；
经典光信号接收机，用于接收第二耦合单元输出的待处理光信号，并从待处理光信号中确定出经典光信号；
量子光信号接收机，用于接收第二耦合单元输出的量子光信号，并进行处理；
其中，待处理光信号中至少包括经典光信号；的经典光信号包括至少一个子经典光信号；经典光信号包括一个子经典光信号时，子经典光信号的波长处于C波段或L波段；
经典光信号包括多个子经典光信号时，多个子经典光信号满足以下内容中的任一项：多个子经典光信号中包括波长处于C波段的子经典光信号；多个子经典光信号中包括波长处于L波段的子经典光信号；多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。
可见，经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，因此经典光信号的波段的波长大于量子光信号的波段的波长，因此，量子光信号可位于反斯托克斯散射区，又由于反斯托克斯散射区的散射强度较小，因此可有效减少量子光信号所受到的拉曼噪声的影响程度，从而提高了通过一根光纤混传经典光信号和量子光信号时量子光信号的质量。
进一步，量子光信号的波长处于S波段，且由于S波段的光纤衰减系数较小，因此当将量子光信号在插损较小的S波段进行传输时，可减轻量子光信号的损耗，从而提高了量 子密钥传输的安全距离。
进一步，由于经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，即经典光信号的波段与量子光信号的波段为两个不同的波段，从而保证了经典光信号的波长和量子光信号的波长之间的距离，如此，可有效降低由于经典光信号的泄露对量子光信号所造成的干扰，以及有效降低经典光信号在传输过程中所产生的FWM对量子光信号所造成的干扰。
可选地，第二耦合单元，具体用于通过位于光纤上的S波段带通滤波器，将耦合后光信号中的量子光信号分离至在光纤中的第四子光纤；并将耦合后光信号中的待处理光信号分离至光纤中的第三子光纤进行处理，从待处理光信号中确定出经典光信号。
本发明实施例中，S波段带通滤波器一方面可以将耦合后光信号中的量子光信号分离至在光纤中的第四子光纤；并将耦合后光信号中的待处理光信号分离至光纤中的第三子光纤进行处理，从而实现经典光信号和量子光信号通过一根光纤传输，进而分别对其进行处理的目的。另一方面，本发明实施例通过S波段带通滤波器可先对量子光信号进行过滤，从而降低噪声光子的影响。
可选地，如果量子光信号只有一个波长，S波段带通滤波器2106的带宽为0.1nm至5nm。优选地，在实际应用中可以使S波段带通滤波器2106的带宽为0.6nm。可选地，如果存在多个子量子光信号，则S波段带通滤波器2106的带宽需覆盖多个子量子光信号的波长，或者需要覆盖整个S波段的波长范围，可选地，S波段带通滤波器2106的带宽范围为0.1nm至70nm。
可选地，经典光信号接收机，具体用于通过光放大器(Optical Amplifier，简称OA)，对待处理光信号进行放大，得到经典光信号。通过OA对经典光信号进行放大，不会对量子光信号造成影响，且由于经典光信号在经过光纤传输时会有损耗，因此通过OA对经典光信号进行放大后再处理，可提高对经典光信号处理的准确度。
可选地，待处理光信号还包括监控光信号，其中，监控光信号位于L波段。经典光信号接收机，具体用于通过L波段和C波段分波器，对待处理光信号进行分波，得到监控光信号和分波后光信号；通过OA，对分波后光信号进行放大，得到经典光信号。
如此，当用较长距离的城际量子通信时，在实际传输过程中设置光放大站点，在这种情况下由于存在中间节点，因此可通过第一光监控信道2207所发送的监控光信号对传输线路进行监控，一方面提高了传输的安全性，另一方面更好的兼容了现有技术中的监控信道的布局，第三，由于监控光信号使用L波段，监控光信号的波段距离量子光信号的波段较远，因此，监控光信号对量子光信号的噪声影响较小。
可选地，存在多个不同波长的子经典光信号时，经典光信号接收机，还用于通过分波器，对经典光信号进行分波处理，得到经典光信号中包括的多个子经典光信号。其中，分波器满足以下条件：
多个子经典光信号中包括波长处于C波段的子经典光信号，分波器为C波段分波器；多个子经典光信号中包括波长处于L波段的子经典光信号，分波器为L波段分波器；多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，分波器为C波段和L波段分波器。
可选地，存在多个不同波长的子量子光信号时，量子光信号接收机，还用于通过S波段分波器，对量子光信号进行分波处理，得到量子光信号中包括的多个子量子光信号。如 此，可通过多个波长同时接收到多个子经典光信号，将多个子经典光信号分离。如此，可同时传输更多的子经典光信号。
可选地，S波段分波器的每个子带的带宽范围为0.1nm至5nm。如此，可综合考虑系统稳定性和S波段分波器与插损等因素，本发明实施例中所设置的S波段分波器的每个子带的带宽一方面可以保证激光器的中心波长不会轻易偏离至S波段分波器的分波长范围之外，从而保证了通信系统的稳定性，另一方面S波段分波器的损耗较小，从而可延长量子通信的安全距离，第三，由于S波段分波器的每个子带的带宽较小，因此不会泄露较多的噪声光子到量子光信号探测器，从而提高了量子密钥的成码率。
本发明实施例提供一种量子通信方法，包括：
发送装置生成待处理光信号和量子光信号；其中，量子光信号的波长处于S波段；发送装置将待处理光信号和量子光信号耦合，得到耦合后光信号；发送装置通过光纤发送耦合后光信号；
其中，待处理光信号中至少包括经典光信号；的经典光信号包括至少一个子经典光信号；经典光信号包括一个子经典光信号时，子经典光信号的波长处于C波段或L波段；
经典光信号包括多个子经典光信号时，多个子经典光信号满足以下内容中的任一项：多个子经典光信号中包括波长处于C波段的子经典光信号；多个子经典光信号中包括波长处于L波段的子经典光信号；多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。
可见，经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，因此经典光信号的波段的波长大于量子光信号的波段的波长，因此，量子光信号可位于反斯托克斯散射区，又由于反斯托克斯散射区的散射强度较小，因此可有效减少量子光信号所受到的拉曼噪声的影响程度，从而提高了通过一根光纤混传经典光信号和量子光信号时量子光信号的质量。
进一步，量子光信号的波长处于S波段，且由于S波段的光纤衰减系数较小，因此当将量子光信号在插损较小的S波段进行传输时，可减轻量子光信号的损耗，从而提高了量子密钥传输的安全距离。
进一步，由于经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，即经典光信号的波段与量子光信号的波段为两个不同的波段，从而保证了经典光信号的波长和量子光信号的波长之间的距离，如此，可有效降低由于经典光信号的泄露对量子光信号所造成的干扰，以及有效降低经典光信号在传输过程中所产生的FWM对量子光信号所造成的干扰。
可选地，发送装置将待处理光信号和量子光信号耦合，得到耦合后光信号，包括发送装置通过位于光纤上的S波段耦合器，将在光纤中的第一子光纤上传输的待处理光信号和在光纤中的第二子光纤上传输的量子光信号耦合，得到耦合后光信号。S波段耦合器可以是光纤耦合器，或者S波段量子光信号和待处理光信号的波分复用器。
可选地，发送装置生成待处理光信号，包括发送装置生成经典光信号，并通过VOA，对生成的经典光信号进行衰减，得到待处理光信号。
可选地，待处理光信号还包括监控光信号，其中，监控光信号位于L波段。发送装置生成待处理光信号，包括发送装置生成经典光信号和监控光信号，并通过VOA，对生成的经典光信号进行衰减，得到衰减后经典光信号；发送装置通过L波段和C波段合波器将衰 减后的经典光信号和监控光信号耦合，得到待处理光信号。由于在发送装置侧，使用VOA对经典光信号进行衰减，并不使用现有技术中常用的EDFA，如此，则彻底消除EDFA所引起的ASE噪声对QKD信道的影响。另一方面，由于光纤传输损耗较低，因此对于城域网通讯系统，对经典光的光功率要求较低，此时，使用VOA对经典光信号进行衰减，完全可以使经典光信号的功率达到传输要求。
可选地，存在多个不同波长的子经典光信号时，发送装置生成经典光信号，包括发送装置通过第一耦合器或合波器，将多个子经典光信号耦合，得到经典光信号。其中，合波器满足以下条件：
多个子经典光信号中包括波长处于C波段的子经典光信号，合波器为C波段合波器；多个子经典光信号中包括波长处于L波段的子经典光信号，合波器为L波段合波器；多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，合波器为C波段和L波段合波器。
可选地，存在多个不同波长的子量子光信号时，发送装置生成量子光信号，包括接收装置通过第二耦合器或S波段合波器，将多个子量子光信号耦合，得到量子光信号。
本发明实施例提供一种量子通信方法，包括：
接收装置通过光纤接收发送装置发送的耦合后光信号；其中，耦合后光信号包括待处理光信号和量子光信号；量子光信号的波长处于S波段；接收装置根据耦合后光信号，确定出经典光信号和量子光信号；
其中，待处理光信号中至少包括经典光信号；的经典光信号包括至少一个子经典光信号；经典光信号包括一个子经典光信号时，子经典光信号的波长处于C波段或L波段；
经典光信号包括多个子经典光信号时，多个子经典光信号满足以下内容中的任一项：多个子经典光信号中包括波长处于C波段的子经典光信号；多个子经典光信号中包括波长处于L波段的子经典光信号；多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。
可见，经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，因此经典光信号的波段的波长大于量子光信号的波段的波长，因此，量子光信号可位于反斯托克斯散射区，又由于反斯托克斯散射区的散射强度较小，因此可有效减少量子光信号所受到的拉曼噪声的影响程度，从而提高了通过一根光纤混传经典光信号和量子光信号时量子光信号的质量。
进一步，量子光信号的波长处于S波段，且由于S波段的光纤衰减系数较小，因此当将量子光信号在插损较小的S波段进行传输时，可减轻量子光信号的损耗，从而提高了量子密钥传输的安全距离。
进一步，由于经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，即经典光信号的波段与量子光信号的波段为两个不同的波段，从而保证了经典光信号的波长和量子光信号的波长之间的距离，如此，可有效降低由于经典光信号的泄露对量子光信号所造成的干扰，以及有效降低经典光信号在传输过程中所产生的FWM对量子光信号所造成的干扰。
可选地，接收装置根据耦合后光信号，确定出经典光信号和量子光信号，包括接收装置通过位于光纤上的S波段带通滤波器，将耦合后光信号中的量子光信号分离至在光纤中的第四子光纤；并将耦合后光信号中的待处理光信号分离至光纤中的第三子光纤进行处理， 从待处理光信号中确定出经典光信号。本发明实施例中，S波段带通滤波器一方面可以将耦合后光信号中的量子光信号分离至在光纤中的第四子光纤；并将耦合后光信号中的待处理光信号分离至光纤中的第三子光纤进行处理，从而实现经典光信号和量子光信号通过一根光纤传输，进而分别对其进行处理的目的。另一方面，本发明实施例通过S波段带通滤波器可先对量子光信号进行过滤，从而降低噪声光子的影响。
可选地，如果量子光信号只有一个波长，S波段带通滤波器2106的带宽为0.1nm至5nm。优选地，在实际应用中可以使S波段带通滤波器2106的带宽为0.6nm。可选地，如果存在多个子量子光信号，则S波段带通滤波器2106的带宽需覆盖多个子量子光信号的波长，或者需要覆盖整个S波段的波长范围，可选地，S波段带通滤波器2106的带宽范围为0.1nm至70nm。
可选地，接收装置从待处理光信号中确定出经典光信号，包括接收装置通过OA，对待处理光信号进行放大，得到经典光信号。通过OA对经典光信号进行放大，不会对量子光信号造成影响，且由于经典光信号在经过光纤传输时会有损耗，因此通过OA对经典光信号进行放大后再处理，可提高对经典光信号处理的准确度。
可选地，待处理光信号还包括监控光信号，其中，监控光信号位于L波段。接收装置从待处理光信号中确定出经典光信号，包括接收装置通过L波段和C波段分波器，对待处理光信号进行分波，得到监控光信号和分波后光信号；接收装置通过OA，对分波后光信号进行放大，得到经典光信号。如此，当用较长距离的城际量子通信时，在实际传输过程中设置光放大站点，在这种情况下由于存在中间节点，因此可通过第一光监控信道2207所发送的监控光信号对传输线路进行监控，一方面提高了传输的安全性，另一方面更好的兼容了现有技术中的监控信道的布局，第三，由于监控光信号使用L波段，监控光信号的波段距离量子光信号的波段较远，因此，监控光信号对量子光信号的噪声影响较小。
可选地，存在多个不同波长的子经典光信号时，接收装置从耦合后光信号中确定出经典光信号之后，还包括接收装置通过分波器，对经典光信号进行分波处理，得到经典光信号中包括的多个子经典光信号。其中，分波器满足以下条件：
多个子经典光信号中包括波长处于C波段的子经典光信号，分波器为C波段分波器；多个子经典光信号中包括波长处于L波段的子经典光信号，分波器为L波段分波器；多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，分波器为C波段和L波段分波器。
可选地，存在多个不同波长的子量子光信号时，接收装置从耦合后光信号中确定出量子光信号之后，还包括接收装置通过S波段分波器，对量子光信号进行分波处理，得到量子光信号中包括的多个子量子光信号。如此，可通过多个波长同时接收到多个子经典光信号，将多个子经典光信号分离。如此，可同时传输更多的子经典光信号。
可选地，S波段分波器的每个子带的带宽范围为0.1nm至5nm。如此，可综合考虑系统稳定性和S波段分波器与插损等因素，本发明实施例中所设置的S波段分波器的每个子带的带宽一方面可以保证激光器的中心波长不会轻易偏离至S波段分波器的分波长范围之外，从而保证了通信系统的稳定性，另一方面S波段分波器的损耗较小，从而可延长量子通信的安全距离，第三，由于S波段分波器的每个子带的带宽较小，因此不会泄露较多的噪声光子到量子光信号探测器，从而提高了量子密钥的成码率。
本发明实施例中，发送装置生成待处理光信号和量子光信号；发送装置将待处理光信 号和量子光信号耦合，得到耦合后光信号；发送装置通过光纤发送耦合后光信号。待处理光信号中至少包括经典光信号；量子光信号的波长处于S波段；其中，待处理光信号中至少包括经典光信号；的经典光信号包括至少一个子经典光信号；经典光信号包括一个子经典光信号时，子经典光信号的波长处于C波段或L波段；经典光信号包括多个子经典光信号时，多个子经典光信号中包括波长处于C波段的子经典光信号，或者多个子经典光信号中包括波长处于L波段的子经典光信号；或者多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。可见，经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，因此经典光信号的波段的波长大于量子光信号的波段的波长，因此，量子光信号可位于反斯托克斯散射区，又由于反斯托克斯散射区的散射强度较小，因此可有效减少量子光信号所受到的拉曼噪声的影响程度，从而提高了通过一根光纤混传经典光信号和量子光信号时量子光信号的质量。
进一步，量子光信号的波长处于S波段，且由于S波段的光纤衰减系数较小，因此当将量子光信号在插损较小的S波段进行传输时，可减轻量子光信号的损耗，从而提高了量子密钥传输的安全距离。
进一步，由于经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，即经典光信号的波段与量子光信号的波段为两个不同的波段，从而保证了经典光信号的波长和量子光信号的波长之间的距离，如此，可有效降低由于经典光信号的泄露对量子光信号所造成的干扰，以及有效降低经典光信号在传输过程中所产生的FWM对量子光信号所造成的干扰。
附图说明
为了更清楚地说明本发明实施例中的技术方案，下面将对实施例描述中所需要使用的附图作简要介绍。
图1为本发明实施例适用的一种系统架构示意图；
图1a示例性示出了本发明实施例提供的一种各波段对应的衰减系数的示意图；
图2为本发明实施例提供的一种量子通信方法流程示意图；
图2a为本发明实施例提供的另一种量子通信方法流程示意图；
图2b为量子光信号对应不同波长时的噪声光子与光纤长度的对应关系示意图；
图2c为本发明实施例提供的一种量子通信系统结构示意图；
图2d为本发明实施例提供的另一种量子通信系统结构示意图；
图2e为本发明实施例提供的另一种量子通信系统结构示意图；
图2f为本发明实施例提供的另一种量子通信系统结构示意图；
图3为本发明实施例提供的一种发送装置的结构示意图；
图4为本发明实施例提供的另一种接收装置的结构示意图。
具体实施方式
为了使本发明的目的、技术方案及有益效果更加清楚明白，以下结合附图及实施例，对本发明进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本发明，并不用于限定本发明。
图1示例性示出了本发明实施例适用的一种系统架构示意图，如图1所示，本发明实 施例适用的系统架构包括发送装置1107和接收装置1108。本发明实施例中的发送装置1107和接收装置1108可分别位于两个网络设备或两个用户设备中；或发送装置1107位于网络设备中，接收装置1108位于用户设备中；或者发送设备位于用户设备中，接收设备位于网络设备中。可选地，通常为了使网络设备兼具发送和接收的功能，网络设备中会通常布置一个发送装置1107和一个接收装置1108，另一端的网络设备中也会布置一个发送装置1107和一个接收装置1108，一端的网络设备中的发送装置1107和另一端的网络设备中的一个接收装置1108为一对本发明实施例中的发送装置1107和接收装置1108；一端的网络设备中的接收装置1108和另一端的网络设备中的一个发送装置1107为另一对本发明实施例中的发送装置1107和接收装置1108。
用户设备可以经无线接入网(Radio Access Network，简称RAN)与一个或多个核心网进行通信，终端设备可以指用户设备(User Equipment，简称UE)、接入终端、用户单元、用户站、移动站、移动台、远方站、远程终端、移动设备、用户终端、终端、无线通信设备、用户代理或用户装置。接入终端可以是蜂窝电话、无绳电话、会话启动协议(Session Initiation Protocol，简称SIP)电话、无线本地环路(Wireless Local Loop，简称WLL)站、个人数字处理(Personal Digital Assistant，简称PDA)、具有无线通信功能的手持设备、计算设备或连接到无线调制解调器的其它处理设备、车载设备、可穿戴设备，未来5G网络中的终端设备等。
网络设备可以是用于与终端设备进行通信的设备，例如，可以是GSM系统或CDMA中的基站(Base Transceiver Station，简称BTS)，也可以是WCDMA系统中的基站(NodeB，简称NB)，还可以是LTE系统中的演进型基站(Evolutional Node B，简称eNB或eNodeB)，或者该网络设备可以为中继站、接入点、车载设备、可穿戴设备以及未来5G网络中的网络侧设备或未来演进的PLMN网络中的网络设备等。
本发明实施例中，发送装置1107中包括的经典光信号发送机2101用于生成经典信号，量子光信号发送机2103用于生成量子光信号，发送装置1107将经典光信号和量子光信号经过第一耦合单元1103的耦合处理，得到耦合后光信号，发送装置1107通过光纤将耦合后光信号发送出去。
接收装置1108通过光纤接收到耦合后光信号，之后接收装置1108通过第二耦合单元1104的解耦合处理，分别将耦合后光信号中的经典光信号分离至经典光信号接收机2102中，将耦合后光信号中的量子光信号分离至量子光信号接收机2104中，并分别做相应处理。
发送装置1107和接收装置1108通过发送经典光信号和量子光信号，分别从量子光信号发送机2103所生成的量子光信号中确定出的量子密钥，发送装置1107使用量子密钥对业务信息进行加密处理，将加密处理之后的业务信息经过经典光信号发送机2101的进一步处理，与量子光信号发送机2103所发送的下一次量子光信号进行耦合，耦合至光纤中进行传输。接收装置1108接收到之后，将耦合后光信号中的经典光信号分离至经典光信号接收机2102中，将耦合后光信号中的量子光信号分离至量子光信号接收机2104中，接收装置1108从量子光信号接收机2104所接收到的量子光信号中确定出量子密钥，并使用量子密钥对经典光信号接收机2102所接收到的经典光信号中的已经进行处理的加密信息进行解密处理，进而恢复出业务信息。
图1a示例性示出了本发明实施例提供的一种各波段对应的衰减系数的示意图，如图 1a所示，横坐标表示波长，单位为nm；纵坐标表示光纤衰减系数，单位为分贝每公里(dB/km)。每个波段对应不同的波长范围，L波段的波长范围为1565nm至1625nm；C波段的波长范围为1530nm至1565nm；S波段的波长范围为1460nm至1530nm；E波段的波长范围为1360nm至1460nm；O波段的波长范围为1260nm至1360nm。如图1a所示，S波段、C波段和E波段的光纤衰减系数小于其它波段的光纤衰减系数，因此，S波段、C波段和E波段的传输光信号时损耗较小。
基于上述内容，本发明实施例提供一种量子通信方案，用于实现经典光信号和量子光信号在一根光纤中传输的目的。
图2示例性示出了本发明实施例提供的一种量子通信方法流程示意图。
基于图1所示的系统架构，如图2所示，本发明实施例提供的发送装置1107侧实现的一种量子通信方法，包括：
步骤201，发送装置生成待处理光信号和量子光信号；量子光信号的波长处于S波段；
步骤202，发送装置将待处理光信号和量子光信号耦合，得到耦合后光信号；
步骤203，发送装置通过光纤发送耦合后光信号；
其中，待处理光信号中至少包括经典光信号；的经典光信号包括至少一个子经典光信号；经典光信号包括一个子经典光信号时，子经典光信号的波长处于C波段或L波段；经典光信号包括多个子经典光信号时，多个子经典光信号满足以下内容中的任一项：多个子经典光信号中包括波长处于C波段的子经典光信号；多个子经典光信号中包括波长处于L波段的子经典光信号；多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。
可选地，经典光信号包括一个子经典光信号时，该一个子经典光信号即为经典光信号；经典光信号包括多个子经典光信号时，多个子经典光信号可经过合波或耦合，从而得到经典光信号。
可见，经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，因此经典光信号的波段的波长大于量子光信号的波段的波长，因此，量子光信号可位于反斯托克斯散射区，又由于反斯托克斯散射区的散射强度较小，因此可有效减少量子光信号所受到的拉曼噪声的影响程度，从而提高了通过一根光纤混传经典光信号和量子光信号时量子光信号的质量。
进一步，量子光信号的波长处于S波段，且由于S波段的光纤衰减系数较小，因此当将量子光信号在插损较小的S波段进行传输时，可减轻量子光信号的损耗，从而提高了量子密钥传输的安全距离。
进一步，由于经典光信号的波长处于L波段和/或C波段，由于量子光信号的波长处于S波段，即经典光信号的波段与量子光信号的波段为两个不同的波段，从而保证了经典光信号的波长和量子光信号的波长之间的距离，如此，可有效降低由于经典光信号的泄露对量子光信号所造成的干扰，以及有效降低经典光信号在传输过程中所产生的FWM对量子光信号所造成的干扰。
可选地，图2a示例性示出了本发明实施例提供的另一种量子通信方法流程示意图，如图2a所示，本发明实施例提供的接收装置1108侧实现的一种量子通信方法包括：
步骤2001，接收装置通过光纤接收发送装置发送的耦合后光信号；其中，耦合后光信号包括待处理光信号和量子光信号；量子光信号的波长处于S波段；
步骤2002，接收装置根据耦合后光信号，确定出经典光信号和量子光信号；
其中，待处理光信号中至少包括经典光信号；的经典光信号包括至少一个子经典光信号；经典光信号包括一个子经典光信号时，子经典光信号的波长处于C波段或L波段；经典光信号包括多个子经典光信号时，多个子经典光信号满足以下内容中的任一项：多个子经典光信号中包括波长处于C波段的子经典光信号；多个子经典光信号中包括波长处于L波段的子经典光信号；多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。
可选地，经典光信号包括一个子经典光信号时，该一个子经典光信号即为经典光信号；经典光信号包括多个子经典光信号时，多个子经典光信号可经过合波或耦合，从而得到经典光信号。
结合图1a所示，量子光信号的波长处于S波段，且S波段为光纤衰减系数较小的波段，也就是说，将量子光信号在S波段进行传输，相比于现有技术中将量子光信号在O波段传输，由于S波段的光纤衰减系数小于O波段的光纤衰减系数，因此S波段传输量子光信号时的损耗小于用O波段传输量子光信号时的损耗，可见，用S波段传输量子光信号，降低了量子光信号的插损，提高了提高了量子密钥传输的安全距离。
具体实施中，在光纤中，自发拉曼散射SRS噪声由泵浦光子与光学声子发生非弹性散射产生，其包括斯托克斯和反斯托克斯散射，增益范围达30THz，增益峰值频偏约为13.2THz，且随着光功率的增加，呈指数增长。通常反斯托克斯散射的强度要弱于斯托克斯散射。
假设不使用本发明实施例的解决方案，而是将量子光信号的波长设置的大于经典光信号的波长，则量子光信号的波长则位于经典光信号的斯托克斯散射区域。以经典光信号位于C波段，量子光信号位于L波段为例进行如下分析：
当经典光信号的功率为Po时，其引起的拉曼噪声强度可表示为公式(1)：
Figure PCTCN2017076830-appb-000001
在公式(1)中，S(L)为经典光功率为Po时，其引起的拉曼噪声强度；
Po为经典光信号的功率；
αP为经典光信号的光纤衰减系数；αs为量子光信号的光纤衰减系数；
βs为量子光信号对应的自发拉曼系数；
L为传输距离。
当系统中有多个经典通道参与时，此时其引起的拉曼噪声强度可表示为公式(2)：
Figure PCTCN2017076830-appb-000002
在公式(2)中：
S(L)为有多个经典通道参与时所引起的拉曼噪声强度；
Poi为第i个经典光信号对应的光功率；i的取值范围为[1，经典光信号的总数量]；
Figure PCTCN2017076830-appb-000003
为所有经典光信号的平均光纤衰减系数；αs为量子光信号的光纤衰减系数；
βsi为量子光信号对应第i个经典光信号的自发拉曼系数；
L为传输距离。
在公式(2)中，由于考虑了多个经典光信号，每个经典光信号的衰减系数有一些差别，因此用
Figure PCTCN2017076830-appb-000004
表示平均的数光纤衰减系数。
不失一般性，下面以仅有一个经典光信号的情况进行分析：
若探测器的波长带宽为Δλ时，则相应的拉曼噪声强度为公式(3)所示：
PSRS＝S(L)×Δλ……公式(3)
在公式(3)中，PSRS为探测器的波长带宽为Δλ时，相应的拉曼噪声强度；
S(L)为公式(1)中的经典光功率为P0时，其引起的拉曼噪声强度。
在估计每时空模式下的平均光子数之前，需要首先确定波长带宽Δλ和时间窗口Δt＝1秒内总的模式数目；由频率与波长的关系，可得公式(4)：
Figure PCTCN2017076830-appb-000005
在公式(4)中，Nmod为带宽Δλ和时间窗口Δt＝1秒内总的模式数目；
λ为量子光信号的波长，c为光速；v为量子光信号的频率，v＝c/λ；
Δt为时间窗口；Δλ为波长带宽；Δv为频率带宽。
由此引起的每时空和偏振模式下的平均噪声光子数如公式(5)所示：
Figure PCTCN2017076830-appb-000006
在公式(5)中：
＜NSRS＞为每时空和偏振模式下的平均噪声光子数；
PSRS为公式(3)中探测器的波长带宽为Δλ时，相应的拉曼噪声强度；
Nmod为公式(4)中波长带宽Δλ和时间窗口Δt＝1秒内总的模式数目；
v为量子光信号的频率；
h为普朗克常数；
ηD为分波器(DEMUX)的透射系数。
将上述公式(1)至公式(4)中的各个参数项代入上述公式(5)，可将公式(5)转换为下述公式(6)：
Figure PCTCN2017076830-appb-000007
在公式(6)中：
＜NSRS＞为每时空和偏振模式下的平均噪声光子数；
P0为经典光信号的功率；
αP为经典光信号的光纤衰减系数；αs为量子光信号的光纤衰减系数；
βs为量子光信号对应的自发拉曼系数；
L为传输距离；
λ为量子光信号的波长，c为光速；
h为普朗克常数；
ηD为分波器(DEMUX)的透射系数。
通过上述公式的推导，假设将经典光信号的波长设置为C波段的1550nm，功率为0dBm，探测器门宽为1ns，滤波带宽为75GHz，分波器(DEMUX)的插损为1.5dB，此时，图2b示例性示出了量子光信号对应不同波长时的噪声光子与光纤长度的对应关系示意图。可见，由于L波段的波长范围为1565nm至1625nm，由于S波段的波长范围为1460nm至1530nm，如图2b所示，横轴表示光纤长度，单位为千米，纵轴表示每纳秒的噪声光子数(图中表示为噪声光子数/纳秒)。在光纤长度一定的情况下，在L波段平均每纳秒产生的拉曼噪声光子数要大于S波段的情形，如1470nm波长的噪声光子仅为1630nm的约十分之一。也就是说，在实际系统中，当经典光信号使用C波段时，量子光信号若工作于L波段，则量子光信号所受到的拉曼噪声光子数过大，此时，会降低量子密钥的成功发送率和量子密钥传输的安全距离，因此量子光信号不宜工作在L波段。
如图2b所示，在光纤长度一定的情况下，量子光信号的波长越长，则量子光信号所对应的噪声光子数量越大，因此，本发明实施例中，量子光信号在S波段传输，经典光信号包括一个子经典光信号时，子经典光信号的波长处于C波段或L波段；经典光信号包括多个子经典光信号时，多个子经典光信号满足以下内容中的任一项：
多个子经典光信号中包括波长处于C波段的子经典光信号；多个子经典光信号中包括波长处于L波段的子经典光信号；多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。可选地，经典光信号包括一个子经典光信号时，该一个子经典光信号即为经典光信号；经典光信号包括多个子经典光信号时，多个子经典光信号可经过合波或耦合，从而得到经典光信号。也就是说，经典光信号中包括的子经典光信号的波长位于C波段的波长范围为1530nm至1565nm内；或者经典光信号中包括的子经典光信号的波长位于L波段的波长范围为1565nm至1625nm内；或者经典光信号中包括的子经典光信号的波长位于L波段和C波段的波长范围为1530nm至1625nm内。
如此，可使经典光信号的波长大于量子光信号的波长，从而使量子光信号位于反斯托克斯散射区，从而降低了量子光信号的波长对应的拉曼噪声光子数量，也就是说相比将量子光信号放置于L波段的方案，本发明实施例中量子光信号的波长处于S波段，此时，量子光信号受到的拉曼噪声光子数量少了接近十倍，也就是说，本发明实施例中，经典光信号的波长处于C波段，量子光信号的波长处于S波段，相对于将量子光信号的波段设置为L波段的方案，量子光信号对C波段产生的拉曼噪声抵抗能力增加了十倍，从而降低了系统的误码率，进一步提高量子密钥的成功发送率。可选地，同时所选的量子光信号的波长需避开斯托克斯和反斯托克斯散射的增益峰值频偏(比如13.2THz)。
进一步，量子光信号的波长处于S波段(比如1470nm)，离经典光信号所使用的C波段、L波段的波长间隔较远，即量子光信号的波段和经典光信号的波段位于不同的波段，从而很好的避免了量子光信号受到FWM和放大自发辐射(Amplified Spontaneous Emission， 简称ASE)噪声的影响，从而降低了系统的误码率，进一步提高量子密钥的成功发送率。
通过上述分析，可见，本发明实施例中不仅仅考虑到在实现经典光信号和量子光信号的同纤混传时，降低量子光信号的损耗，同时还降低了由经典光信号引起的噪声光子对量子光信号的影响程度，从而进一步提高量子密钥传输的安全距离。
图2c示例性示出了本发明实施例提供的一种量子通信系统结构示意图。如图2c所示，发送装置1107包括S波段耦合器2105，接收装置1108包括S波段带通滤波器2106。S波段耦合器2105可为图1中的第一耦合单元1103。S波段带通滤波器2106可为图1中的第二耦合单元1104。
可选地，如图2c所示，发送装置1107将待处理光信号和量子光信号耦合，得到耦合后光信号，包括：
发送装置1107通过位于光纤2109上的S波段耦合器2105，将在光纤2109中的第一子光纤2107上传输的待处理光信号和在光纤2109中的第二子光纤2108上传输的量子光信号耦合，得到耦合后光信号。
本发明实施例中，S波段耦合器2105一方面可以将第一子光纤2107上传输的待处理光信号和在光纤2109中的第二子光纤2108上传输的S波段的量子光信号耦合，从而实现经典光信号和S波段的量子光信号通过一根光纤传输的目的。S波段耦合器可以是光纤耦合器，或者S波段量子光信号和待处理光信号的波分复用器。
具体实施中，降低噪声光子对量子光信号影响的本质即是降低最终泄漏到量子光信号探测器的噪声光子数目，因此，通过S波段带通滤波器2106可有效的滤除量子光信号波段周围的噪声光子，从而减少最终到达量子光信号探测器的噪声光子数目。可选地，如图2c所示，接收装置1108根据耦合后光信号，确定出经典光信号和量子光信号，包括：
接收装置1108通过位于光纤2109上的S波段带通滤波器2106，将耦合后光信号中的量子光信号分离至在光纤2109中的第四子光纤2111；并将耦合后光信号中的待处理光信号分离至光纤2109中的第三子光纤2110进行处理，从待处理光信号中确定出经典光信号。
本发明实施例中，S波段带通滤波器2106一方面可以将耦合后光信号中的量子光信号分离至在光纤2109中的第四子光纤2111；并将耦合后光信号中的待处理光信号分离至光纤2109中的第三子光纤2110进行处理，从而实现经典光信号和量子光信号通过一根光纤传输，进而分别对其进行处理的目的。另一方面，本发明实施例通过S波段带通滤波器2106可先对量子光信号进行过滤，从而降低噪声光子的影响。
具体实施中，采用S波段带通滤波器2106分离量子光信号发送机2103输出的S波段的量子光信号和经典光信号时，需要权衡S波段带通滤波器2106的滤波带宽与输出的量子光信号的激光器稳定性。由于各种不稳定因素，如温度变化、大气变化、机械振动、磁场变化的影响，实际量子光信号的激光频率的漂移明显，如果不采用本发明实施例中的S波段带通滤波器2106，而是采用超窄带的带通滤波片，则量子光信号的中心波长容易偏离至超窄带的带通滤波片的滤波范围之外，从而导致超窄带的带通滤波片将量子光信号也滤去，从而导致量子光信号无法传输，而且同时超窄带的带通滤波片会引入较大的损耗。但是，另一方面，若S波段带通滤波器2106的带宽较大，则会泄露更多的噪声光子到量子光信号探测器，从而影响最终的量子密钥的成码率。
可选地，如果量子光信号只有一个波长，S波段带通滤波器2106的带宽为0.1nm至5nm。优选地，在实际应用中可以使S波段带通滤波器2106的带宽为0.6nm。可选地，如 果存在多个子量子光信号，则S波段带通滤波器2106的带宽需覆盖多个子量子光信号的波长，或者需要覆盖整个S波段的波长范围，可选地，S波段带通滤波器2106的带宽范围为0.1nm至70nm。
如此，可综合考虑系统稳定性和S波段带通滤波器2106与插损等因素，本发明实施例中所设置的S波段带通滤波器2106的带宽一方面可以保证激光器的中心波长不会轻易偏离至S波段带通滤波器2106的滤波范围之外，从而保证了通信系统的稳定性，另一方面S波段带通滤波器2106的损耗较小，从而可延长量子通信的安全距离，第三，由于S波段带通滤波器2106的带宽较小，因此不会泄露较多的噪声光子到量子光信号探测器，从而提高了量子密钥的成码率。
进一步，由于经典光信号和量子光信号位于不同的波段，距离较远，因此S波段带通滤波器2106的性能不需要很高，即可实现滤去经典光信号对量子光信号的噪声光子的目的，从而降低了量子通信系统的成本。
图2d示例性示出了本发明实施例提供的另一种量子通信系统结构示意图。如图2d所示，可选地，发送装置1107生成待处理光信号，包括：发送装置1107生成经典光信号，并通过VOA2205，对生成的经典光信号进行衰减，得到待处理光信号。
由于在发送装置1107侧，使用VOA2205对经典光信号进行衰减，并不使用现有技术中常用的EDFA，如此，则彻底消除EDFA所引起的ASE噪声对QKD信道的影响。另一方面，由于光纤传输损耗较低，因此对于城域网通讯系统，对经典光的光功率要求较低，此时，使用VOA2205对经典光信号进行衰减，完全可以使经典光信号的功率达到传输要求。
可选地，接收装置1108从待处理光信号中确定出经典光信号，包括：接收装置1108通过OA2305，对待处理光信号进行放大，得到经典光信号。具体来说，接收装置1108将经典光信号和量子光信号进行分离之后，通过OA对经典光信号进行放大，不会对量子光信号造成影响，且由于经典光信号在经过光纤传输时会有损耗，因此通过OA对经典光信号进行放大后再处理，可提高对经典光信号处理的准确度。
图2e示例性示出了本发明实施例提供的另一种量子通信系统结构示意图。如图2e所示，经典光信号发送机2101将经典光信号的第一光监控信道2207产生的监控光信号通过L波段和C波段合波器2206进行耦合，耦合至第一子光纤2107进行传输。可选地，本发明实施例中的分波器和合波器基于波分复用系统。也就是说，本发明实施例中在现有WDM系统(主通道+监控信道)上叠加一个量子光信号发送机2103。可选地，如图2e所示，在发送装置1107侧，待处理光信号还包括监控光信号，其中，监控光信号位于L波段；
发送装置1107生成待处理光信号，包括：
发送装置1107生成经典光信号和监控光信号，并通过VOA，对生成的经典光信号进行衰减，得到衰减后经典光信号；
发送装置1107通过L波段和C波段合波器2206将衰减后的经典光信号和监控光信号耦合，得到待处理光信号。
如此，当用较长距离的城际量子通信时，在实际传输过程中设置光放大站点，在这种情况下由于存在中间节点，因此可通过第一光监控信道2207所发送的监控光信号对传输线路进行监控，一方面提高了传输的安全性，另一方面更好的兼容了现有技术中的监控信道的布局，第三，由于监控光信号使用L波段，监控光信号的波段距离量子光信号的波段 较远，因此，监控光信号对量子光信号的噪声影响较小。
可选地，如图2e所示，在接收装置1108侧，待处理光信号还包括监控光信号，其中，监控光信号位于L波段；
接收装置1108从待处理光信号中确定出经典光信号，包括：
接收装置1108通过L波段和C波段分波器2306，对待处理光信号进行分波，得到监控光信号和分波后光信号；接收装置1108通过OA，对分波后光信号进行放大，得到经典光信号。
如此，当用较长距离的城际量子通信时，在实际传输过程中设置光放大站点，在这种情况下由于存在中间节点，因此可通过第二光监控信道2307所接收到的监控光信号对传输线路进行监控，一方面提高了传输的安全性，另一方面更好的兼容了现有技术中的监控信道的布局，第三，由于监控光信号使用L波段，监控光信号的波段距离量子光信号的波段较远，因此，监控光信号对量子光信号的噪声影响较小。第四，实现了经典光信号、监控光信号的成功分离，从而可分别对其进行处理，实现其各自的作用。
图2f示例性示出了本发明实施例提供的另一种量子通信系统结构示意图。如图2f所示，可选地，在发送装置1107侧存在多个不同波长的子经典光信号时，发送装置1107生成经典光信号，包括：发送装置1107通过第一耦合器或合波器2204，将多个子经典光信号耦合，得到经典光信号；其中，合波器2204满足以下条件：
多个子经典光信号中包括波长处于C波段的子经典光信号，合波器2204为C波段合波器；
多个子经典光信号中包括波长处于L波段的子经典光信号，合波器2204为L波段合波器；
多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，合波器2204为C波段和L波段合波器。
可选地，发送装置1107通过第一耦合器或合波器2204，将多个子经典光信号耦合，得到经典光信号。如此，可更加简化通信系统，便于操作，且进一步降低系统中的插损。
如此，可通过多个波长同时发送多个子经典光信号，比如图2f中的子经典光信号2201、子经典光信号2202、…子经典光信号2203等等。通过第一耦合器或合波器2204，将多个子经典光信号耦合，并通过光纤进行传输。如此，可同时传输更多的子经典光信号。本发明实施例中经典信息可为协商信息、业务信息和同步时钟信号中的任一项或任几项的信息，每个子经典光信号也可为协商信息、业务信息和同步时钟信号中的任一项或任几项的信息。具体来说，比如一个子经典光信号可为用于使接收装置和发送装置协商出量子密钥的协商信息，或者是通过量子密钥加密后的业务信息。
可选地，在接收装置1108侧，存在多个不同波长的子经典光信号时，接收装置1108从耦合后光信号中确定出经典光信号之后，还包括：接收装置1108通过分波器2304，对经典光信号进行分波处理，得到经典光信号中包括的多个子经典光信号；其中，分波器分波器满足以下条件：
多个子经典光信号中包括波长处于C波段的子经典光信号，分波器分波器为C波段分波器；
多个子经典光信号中包括波长处于L波段的子经典光信号，分波器分波器为L波段分波器；
多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，分波器分波器为C波段和L波段分波器。
如此，可通过多个波长同时接收到多个子经典光信号，比如图2f中的子经典光信号2301、子经典光信号2302、…子经典光信号2303等等。通过分波器2304，将多个子经典光信号分离。如此，可同时传输更多的子经典光信号。
如图2f所示，可选地，在发送装置1107侧，存在多个不同波长的子量子光信号时：发送装置1107生成量子光信号，包括：接收装置1108通过第二耦合器或S波段合波器2404，将多个子量子光信号耦合，得到量子光信号。
可选地，接收装置1108通过第二耦合器，将多个子量子光信号耦合，得到量子光信号。比如图2f中的子量子光信号2401、子量子光信号2402、…子量子光信号2403等等。如此，可更加简化通信系统，便于操作，且进一步降低系统中的插损。本发明实施例中量子光信号可为以量子态为信息载体的光信号，比如可为一组随机数，该组随机数可以用于生成最终的量子密钥。本发明实施例中的每个子量子光信号可为以量子态为信息载体的光信号，比如一个子量子光信号可为一组随机数，该组随机数可以用于生成最终的量子密钥。
由于量子光信号和发送光信号在一根光纤中进行混传，相比单独传输量子光信号的方案，不可避免的会使量子光信号受到一定的噪声影响，降低量子密钥的生成率，为了进一步提高量子密钥生成率，本发明实施例中通过多个波长同时传输多个子量子光信号，从而增大了子量子光信号的传输率，从而加大了量子密钥的生成速率，从而可对更多的经典光信号进行加密，从而提高了量子通信的通信效率。
如图2f所示，可选地，在接收装置1108侧，存在多个不同波长的子量子光信号时：接收装置1108从耦合后光信号中确定出量子光信号之后，还包括：接收装置1108通过S波段分波器2504，对量子光信号进行分波处理，得到量子光信号中包括的多个子量子光信号。比如图2f中的子量子光信号2501、子量子光信号2502、…子量子光信号2503等等。
由于量子光信号和发送光信号在一根光纤中进行混传，相比单独传输量子光信号的方案，不可避免的会使量子光信号受到一定的噪声影响，降低量子密钥的生成率，为了进一步提高量子密钥生成率，本发明实施例中通过多个波长同时传输多个子量子光信号，从而增大了子量子光信号的传输率，从而加大了量子密钥的生成速率，从而可对更多的经典光信号进行加密，从而提高了量子通信的通信效率。
具体实施中，采用S波段分波器2504对量子信号进行分波处理时，需要权衡S波段分波器2504的每个子带的带宽与输出的量子光信号的激光器稳定性。由于各种不稳定因素，如温度变化、大气变化、机械振动、磁场变化的影响，实际量子光信号的激光频率的漂移明显，如果不采用本发明实施例中的S波段分波器2504，而是采用超窄带的带通滤波片，则量子光信号的中心波长容易偏离至超窄带的带通滤波片的滤波范围之外，从而导致超窄带的带通滤波片将量子光信号也滤去，从而导致量子光信号无法传输，而且同时超窄带的带通滤波片会引入较大的损耗。但是，另一方面，若S波段分波器2504的每个子带的带宽较大，则会泄露更多的噪声光子到量子光信号探测器，从而影响最终的量子密钥的成码率。可选地，S波段分波器2504的每个子带的带宽范围为0.1nm至5nm。优选地，在实际应用中可以使S波段分波器2504的每个子带的带宽为0.6nm。如此，可综合考虑系统稳定性和S波段分波器2504与插损等因素，本发明实施例中所设置的S波段分波器2504的每个子带的带宽一方面可以保证激光器的中心波长不会轻易偏离至S波段分波器2504 的分波长范围之外，从而保证了通信系统的稳定性，另一方面S波段分波器2504的损耗较小，从而可延长量子通信的安全距离，第三，由于S波段分波器2504的每个子带的带宽较小，因此不会泄露较多的噪声光子到量子光信号探测器，从而提高了量子密钥的成码率。
基于上述论述，为了更加清楚的介绍本发明实施例，下面以图2f为例对本发明实施例进行详细介绍。
如图2f所示，在发送装置1107侧：
可选地，存在多个不同波长的子经典光信号时。通过第一耦合器或合波器2204，将多个子经典光信号耦合，得到经典光信号，之后通过可调光衰减器2205对经典光信号进行衰减，得到衰减后经典光信号。第一光监控信道2207产生监控光信号，通过L波段和C波段合波器2206将衰减后的经典光信号和监控光信号耦合，得到待处理光信号，并在第一子光纤2107上传输待处理光信号。
可选地，存在多个不同波长的子量子光信号时。通过第二耦合器或S波段合波器2404，将多个子量子光信号耦合，得到量子光信号，量子光信号在第二子光纤2108上传输。
发送装置1107通过位于光纤2109上的S波段耦合器2105，将在光纤2109中的第一子光纤2107上传输的待处理光信号和在光纤2109中的第二子光纤2108上传输的量子光信号耦合，得到耦合后光信号。
发送装置1107通过光纤将耦合后光信号发送出去。
在接收装置1108侧：
接收装置1108通过光纤接收到耦合后光信号。
接收装置1108通过位于光纤2109上的S波段带通滤波器2106，将耦合后光信号中的量子光信号分离至在光纤2109中的第四子光纤2111；并将耦合后光信号中的待处理光信号分离至光纤2109中的第三子光纤2110进行处理。
接收装置1108通过L波段和C波段分波器2306，对待处理光信号进行分波，得到监控光信号和分波后光信号。
接收装置1108通过OA，对分波后光信号进行放大，得到经典光信号。
接收装置1108通过S波段分波器2504，对量子光信号进行分波处理，得到量子光信号中包括的多个子量子光信号。
接收装置1108和发送装置1107进一步根据各自接收到的经典光信号、量子光信号和监控光信号确定出量子密钥，从而发送装置1107使用量子密钥对业务信息进行加密，并将加密后的业务信息发送给接收装置1108，接收装置1108使用确定出的量子密钥对该业务信息进行解密，从而得到业务信息。
从上述内容可以看出：由于经典光信号的波长处于L波段和/或C波段，量子光信号的波长处于S波段，因此经典光信号的波段的波长大于量子光信号的波段的波长，因此，量子光信号可位于反斯托克斯散射区，又由于反斯托克斯散射区的散射强度较小，因此可有效减少量子光信号所受到的拉曼噪声的影响程度，从而提高了通过一根光纤混传经典光信号和量子光信号时量子光信号的质量。
图3示例性示出了本发明实施例提供的一种用于量子通信的发送装置1107的结构示意图。
基于相同构思，本发明实施例提供一种用于量子通信的发送装置1107，如图3所示， 该发送装置1107包括经典光信号发送机2101、量子光信号发送机2103、第一耦合单元1103、发送单元3101：
经典光信号发送机2101，用于生成待处理光信号；
量子光信号发送机2103，用于生成量子光信号；其中，待处理光信号中至少包括经典光信号；量子光信号的波长处于S波段；
第一耦合单元1103，用于将待处理光信号和量子光信号耦合，得到耦合后光信号；
发送单元3101，用于通过光纤发送耦合后光信号。
可选地，经典光信号的波长处于以下内容中的任一种：C波段；L波段；L波段和C波段。
可选地，第一耦合单元1103，具体用于：
通过位于光纤2109上的S波段耦合器2105，将在光纤2109中的第一子光纤2107上传输的待处理光信号和在光纤2109中的第二子光纤2108上传输的量子光信号耦合，得到耦合后光信号。
可选地，经典光信号发送机2101，具体用于：
生成经典光信号，并
通过VOA，对生成的经典光信号进行衰减，得到待处理光信号。
可选地，待处理光信号还包括监控光信号，其中，监控光信号位于L波段；
经典光信号发送机2101，具体用于：
生成经典光信号和监控光信号，并
通过VOA，对生成的经典光信号进行衰减，得到衰减后经典光信号；
通过L波段和C波段合波器2206将衰减后的经典光信号和监控光信号耦合，得到待处理光信号。
可选地，存在多个不同波长的子经典光信号时：
经典光信号发送机2101，具体用于：
通过第一耦合器或合波器2204，将多个子经典光信号耦合，得到经典光信号；其中，合波器满足以下条件：
多个子经典光信号中包括波长处于C波段的子经典光信号，合波器为C波段合波器；
多个子经典光信号中包括波长处于L波段的子经典光信号，合波器为L波段合波器；
多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，合波器为C波段和L波段合波器。
可选地，存在多个不同波长的子量子光信号时：
量子光信号发送机2103，具体用于：
通过第二耦合器或S波段合波器2404，将多个子量子光信号耦合，得到量子光信号。
从上述内容可以看出：本发明实施例中，由于经典光信号的波长处于L波段和/或C波段，量子光信号的波长处于S波段，因此经典光信号的波段的波长大于量子光信号的波段的波长，因此，量子光信号可位于反斯托克斯散射区，又由于反斯托克斯散射区的散射强度较小，因此可有效减少量子光信号所受到的拉曼噪声的影响程度，从而提高了通过一根光纤混传经典光信号和量子光信号时量子光信号的质量。
图4示例性示出了本发明实施例提供的一种用于量子通信的接收装置1108的结构示意图。
基于相同构思，本发明实施例提供一种用于量子通信的接收装置1108，如图4所示，该接收装置1108包括经典光信号接收机2102、量子光信号接收机2104、第二耦合单元1104、接收单元4101：
接收单元4101，用于通过光纤接收发送装置1107发送的耦合后光信号；其中，耦合后光信号包括待处理光信号和量子光信号；待处理光信号中至少包括经典光信号；量子光信号的波长处于S波段；
第二耦合单元1104，用于从耦合后光信号中确定出待处理光信号和量子光信号；
经典光信号接收机2102，用于接收第二耦合单元1104输出的待处理光信号，并从待处理光信号中确定出经典光信号；
量子光信号接收机2104，用于接收第二耦合单元1104输出的量子光信号，并进行处理。
可选地，经典光信号的波长处于以下内容中的任一种：C波段；L波段；L波段和C波段。
可选地，第二耦合单元1104，具体用于：
通过位于光纤2109上的S波段带通滤波器2106，将耦合后光信号中的量子光信号分离至在光纤2109中的第四子光纤2111；并将耦合后光信号中的待处理光信号分离至光纤2109中的第三子光纤2110进行处理，从待处理光信号中确定出经典光信号。
可选地，S波段带通滤波器2106的带宽范围为0.1nm至70nm。
可选地，经典光信号接收机2102，具体用于：
通过OA，对待处理光信号进行放大，得到经典光信号。
可选地，其特征在于，待处理光信号还包括监控光信号，其中，监控光信号位于L波段；
经典光信号接收机2102，具体用于：
通过L波段和C波段分波器2306，对待处理光信号进行分波，得到监控光信号和分波后光信号；
通过OA，对分波后光信号进行放大，得到经典光信号。
可选地，存在多个不同波长的子经典光信号时：
经典光信号接收机2102，还用于：
通过分波器2304，对经典光信号进行分波处理，得到经典光信号中包括的多个子经典光信号；其中，分波器满足以下条件：
多个子经典光信号中包括波长处于C波段的子经典光信号，分波器为C波段分波器；
多个子经典光信号中包括波长处于L波段的子经典光信号，分波器为L波段分波器；
多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，分波器为C波段和L波段分波器。
可选地，存在多个不同波长的子量子光信号时：
量子光信号接收机2104，还用于：
通过S波段分波器2504，对量子光信号进行分波处理，得到量子光信号中包括的多个子量子光信号。
可选地，S波段分波器的每个子带的带宽范围为0.1nm至5nm。
从上述内容可以看出：由于经典光信号的波长处于L波段和/或C波段，量子光信号 的波长处于S波段，因此经典光信号的波段的波长大于量子光信号的波段的波长，因此，量子光信号可位于反斯托克斯散射区，又由于反斯托克斯散射区的散射强度较小，因此可有效减少量子光信号所受到的拉曼噪声的影响程度，从而提高了通过一根光纤混传经典光信号和量子光信号时量子光信号的质量。
本领域内的技术人员应明白，本发明的实施例可提供为方法、或计算机程序产品。因此，本发明可采用完全硬件实施例、完全软件实施例、或结合软件和硬件方面的实施例的形式。而且，本发明可采用在一个或多个其中包含有计算机可用程序代码的计算机可用存储介质(包括但不限于磁盘存储器、CD-ROM、光学存储器等)上实施的计算机程序产品的形式。
本发明是参照根据本发明实施例的方法、设备(系统)、和计算机程序产品的流程图和/或方框图来描述的。应理解可由计算机程序指令实现流程图和/或方框图中的每一流程和/或方框、以及流程图和/或方框图中的流程和/或方框的结合。可提供这些计算机程序指令到通用计算机、专用计算机、嵌入式处理机或其他可编程数据处理设备的处理器以产生一个机器，使得通过计算机或其他可编程数据处理设备的处理器执行的指令产生用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的装置。
这些计算机程序指令也可存储在能引导计算机或其他可编程数据处理设备以特定方式工作的计算机可读存储器中，使得存储在该计算机可读存储器中的指令产生包括指令装置的制造品，该指令装置实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能。
这些计算机程序指令也可装载到计算机或其他可编程数据处理设备上，使得在计算机或其他可编程设备上执行一系列操作步骤以产生计算机实现的处理，从而在计算机或其他可编程设备上执行的指令提供用于实现在流程图一个流程或多个流程和/或方框图一个方框或多个方框中指定的功能的步骤。
尽管已描述了本发明的优选实施例，但本领域内的技术人员一旦得知了基本创造性概念，则可对这些实施例作出另外的变更和修改。所以，所附权利要求意欲解释为包括优选实施例以及落入本发明范围的所有变更和修改。
显然，本领域的技术人员可以对本发明进行各种改动和变型而不脱离本发明的精神和范围。这样，倘若本发明的这些修改和变型属于本发明权利要求及其等同技术的范围之内，则本发明也意图包含这些改动和变型在内。

Claims (28)

  1. 一种用于量子通信的发送装置，其特征在于，包括：
    经典光信号发送机，用于生成待处理光信号；
    量子光信号发送机，用于生成量子光信号；所述量子光信号的波长处于S波段；
    第一耦合单元，用于将所述待处理光信号和所述量子光信号耦合，得到耦合后光信号；
    发送单元，用于通过光纤发送所述耦合后光信号；
    其中，所述待处理光信号中至少包括经典光信号；所述的经典光信号包括至少一个子经典光信号；
    所述经典光信号包括一个子经典光信号时，所述子经典光信号的波长处于C波段或L波段；
    所述经典光信号包括多个子经典光信号时，所述多个子经典光信号满足以下内容中的任一项：
    所述多个子经典光信号中包括波长处于C波段的子经典光信号；
    所述多个子经典光信号中包括波长处于L波段的子经典光信号；
    所述多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。
  2. 如权利要求1所述的发送装置，其特征在于，所述第一耦合单元，具体用于：
    通过位于所述光纤上的S波段耦合器，将在所述光纤中的第一子光纤上传输的所述待处理光信号和在所述光纤中的第二子光纤上传输的所述量子光信号耦合，得到所述耦合后光信号。
  3. 如权利要求1或2所述的发送装置，其特征在于，所述经典光信号发送机，具体用于：
    生成经典光信号，并
    通过可变光衰减器VOA，对生成的所述经典光信号进行衰减，得到所述待处理光信号。
  4. 如权利要求1或2所述的发送装置，其特征在于，所述待处理光信号还包括监控光信号，其中，所述监控光信号位于L波段；
    所述经典光信号发送机，具体用于：
    生成经典光信号和监控光信号，并
    通过可变光衰减器VOA，对生成的所述经典光信号进行衰减，得到衰减后经典光信号；
    通过L波段和C波段合波器将衰减后的经典光信号和所述监控光信号耦合，得到所述待处理光信号。
  5. 如权利要求3或4所述的发送装置，其特征在于，存在多个不同波长的子经典光信号时：
    所述经典光信号发送机，具体用于：
    通过第一耦合器或合波器，将所述多个子经典光信号耦合，得到所述经典光信号；其中，所述合波器满足以下条件：
    所述多个子经典光信号中包括波长处于C波段的子经典光信号，所述合波器为C波段合波器；
    所述多个子经典光信号中包括波长处于L波段的子经典光信号，所述合波器为L波段 合波器；
    所述多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，所述合波器为C波段和L波段合波器。
  6. 如权利要求1至5任一权利要求所述的发送装置，其特征在于，存在多个不同波长的子量子光信号时：
    所述量子光信号发送机，具体用于：
    通过第二耦合器或S波段合波器，将所述多个子量子光信号耦合，得到所述量子光信号。
  7. 一种用于量子通信的接收装置，其特征在于，包括：
    接收单元，用于通过光纤接收发送装置发送的耦合后光信号；其中，所述耦合后光信号包括待处理光信号和量子光信号；所述量子光信号的波长处于S波段；
    第二耦合单元，用于从所述耦合后光信号中确定出所述待处理光信号和所述量子光信号；
    经典光信号接收机，用于接收所述第二耦合单元输出的所述待处理光信号，并从所述待处理光信号中确定出所述经典光信号；
    量子光信号接收机，用于接收所述第二耦合单元输出的所述量子光信号，并进行处理；
    其中，所述待处理光信号中至少包括经典光信号；所述的经典光信号包括至少一个子经典光信号；
    所述经典光信号包括一个子经典光信号时，所述子经典光信号的波长处于C波段或L波段；
    所述经典光信号包括多个子经典光信号时，所述多个子经典光信号满足以下内容中的任一项：
    所述多个子经典光信号中包括波长处于C波段的子经典光信号；
    所述多个子经典光信号中包括波长处于L波段的子经典光信号；
    所述多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。
  8. 如权利要求7所述的接收装置，其特征在于，所述第二耦合单元，具体用于：
    通过位于所述光纤上的S波段带通滤波器，将所述耦合后光信号中的所述量子光信号分离至在所述光纤中的第四子光纤；并将所述耦合后光信号中的所述待处理光信号分离至所述光纤中的第三子光纤进行处理，从所述待处理光信号中确定出所述经典光信号。
  9. 如权利要求8所述的接收装置，其特征在于，所述S波段带通滤波器的带宽范围为0.1纳米nm至70nm。
  10. 如权利要求8或9所述的接收装置，其特征在于，所述经典光信号接收机，具体用于：
    通过光放大器OA，对所述待处理光信号进行放大，得到所述经典光信号。
  11. 如权利要求8或9所述的接收装置，其特征在于，所述待处理光信号还包括监控光信号，其中，所述监控光信号位于L波段；
    所述经典光信号接收机，具体用于：
    通过L波段和C波段分波器，对所述待处理光信号进行分波，得到监控光信号和分波后光信号；
    通过光放大器OA，对所述分波后光信号进行放大，得到所述经典光信号。
  12. 如权利要求7至11任一权利要求所述的接收装置，其特征在于，存在多个不同波长的子经典光信号时：
    所述经典光信号接收机，还用于：
    通过分波器，对所述经典光信号进行分波处理，得到所述经典光信号中包括的所述多个子经典光信号；其中，所述分波器满足以下条件：
    所述多个子经典光信号中包括波长处于C波段的子经典光信号，所述分波器为C波段分波器；
    所述多个子经典光信号中包括波长处于L波段的子经典光信号，所述分波器为L波段分波器；
    所述多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，所述分波器为C波段和L波段分波器。
  13. 如权利要求7至12任一权利要求所述的接收装置，其特征在于，存在多个不同波长的子量子光信号时：
    所述量子光信号接收机，还用于：
    通过S波段分波器，对所述量子光信号进行分波处理，得到所述量子光信号中包括的所述多个子量子光信号。
  14. 如权利要求13所述的接收装置，其特征在于，所述S波段分波器的每个子带的带宽范围为0.1nm至5nm。
  15. 一种量子通信方法，其特征在于，包括：
    发送装置生成待处理光信号和量子光信号；其中，所述量子光信号的波长处于S波段；
    所述发送装置将所述待处理光信号和所述量子光信号耦合，得到耦合后光信号；
    所述发送装置通过光纤发送所述耦合后光信号；
    其中，所述待处理光信号中至少包括经典光信号；所述的经典光信号包括至少一个子经典光信号；
    所述经典光信号包括一个子经典光信号时，所述子经典光信号的波长处于C波段或L波段；
    所述经典光信号包括多个子经典光信号时，所述多个子经典光信号满足以下内容中的任一项：
    所述多个子经典光信号中包括波长处于C波段的子经典光信号；
    所述多个子经典光信号中包括波长处于L波段的子经典光信号；
    所述多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。
  16. 如权利要求15所述的方法，其特征在于，所述发送装置将所述待处理光信号和所述量子光信号耦合，得到耦合后光信号，包括：
    所述发送装置通过位于所述光纤上的S波段耦合器，将在所述光纤中的第一子光纤上传输的所述待处理光信号和在所述光纤中的第二子光纤上传输的所述量子光信号耦合，得到所述耦合后光信号。
  17. 如权利要求15或16所述的方法，其特征在于，所述发送装置生成待处理光信号，包括：
    所述发送装置生成经典光信号，并
    通过可变光衰减器VOA，对生成的所述经典光信号进行衰减，得到所述待处理光信号。
  18. 如权利要求15或16所述的方法，其特征在于，所述待处理光信号还包括监控光信号，其中，所述监控光信号位于L波段；
    所述发送装置生成待处理光信号，包括：
    所述发送装置生成经典光信号和监控光信号，并
    通过可变光衰减器VOA，对生成的所述经典光信号进行衰减，得到衰减后经典光信号；
    所述发送装置通过L波段和C波段合波器将衰减后的经典光信号和所述监控光信号耦合，得到所述待处理光信号。
  19. 如权利要求17或18所述的方法，其特征在于，存在多个不同波长的子经典光信号时：
    所述发送装置生成经典光信号，包括：
    所述发送装置通过第一耦合器或合波器，将所述多个子经典光信号耦合，得到所述经典光信号；其中，所述合波器满足以下条件：
    所述多个子经典光信号中包括波长处于C波段的子经典光信号，所述合波器为C波段合波器；
    所述多个子经典光信号中包括波长处于L波段的子经典光信号，所述合波器为L波段合波器；
    所述多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，所述合波器为C波段和L波段合波器。
  20. 如权利要求15至19任一权利要求所述的方法，其特征在于，存在多个不同波长的子量子光信号时：
    所述发送装置生成量子光信号，包括：
    所述接收装置通过第二耦合器或S波段合波器，将所述多个子量子光信号耦合，得到所述量子光信号。
  21. 一种量子通信方法，其特征在于，包括：
    接收装置通过光纤接收发送装置发送的耦合后光信号；其中，所述耦合后光信号包括待处理光信号和量子光信号；所述量子光信号的波长处于S波段；
    所述接收装置根据所述耦合后光信号，确定出所述经典光信号和所述量子光信号；
    其中，所述待处理光信号中至少包括经典光信号；所述的经典光信号包括至少一个子经典光信号；
    所述经典光信号包括一个子经典光信号时，所述子经典光信号的波长处于C波段或L波段；
    所述经典光信号包括多个子经典光信号时，所述多个子经典光信号满足以下内容中的任一项：
    所述多个子经典光信号中包括波长处于C波段的子经典光信号；
    所述多个子经典光信号中包括波长处于L波段的子经典光信号；
    所述多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号。
  22. 如权利要求21所述的方法，其特征在于，所述接收装置根据所述耦合后光信号， 确定出所述经典光信号和所述量子光信号，包括：
    所述接收装置通过位于所述光纤上的S波段带通滤波器，将所述耦合后光信号中的所述量子光信号分离至在所述光纤中的第四子光纤；并将所述耦合后光信号中的所述待处理光信号分离至所述光纤中的第三子光纤进行处理，从所述待处理光信号中确定出所述经典光信号。
  23. 如权利要求22所述的方法，其特征在于，所述S波段带通滤波器的带宽范围为0.1nm至70nm。
  24. 如权利要求22或23所述的方法，其特征在于，所述接收装置从所述待处理光信号中确定出所述经典光信号，包括：
    所述接收装置通过光放大器OA，对所述待处理光信号进行放大，得到所述经典光信号。
  25. 如权利要求22或23所述的方法，其特征在于，所述待处理光信号还包括监控光信号，其中，所述监控光信号位于L波段；
    所述接收装置从所述待处理光信号中确定出所述经典光信号，包括：
    所述接收装置通过L波段和C波段分波器，对所述待处理光信号进行分波，得到监控光信号和分波后光信号；
    所述接收装置通过光放大器OA，对所述分波后光信号进行放大，得到所述经典光信号。
  26. 如权利要求21至25任一权利要求所述的方法，其特征在于，存在多个不同波长的子经典光信号时：
    所述接收装置从所述耦合后光信号中确定出所述经典光信号之后，还包括：
    所述接收装置通过分波器，对所述经典光信号进行分波处理，得到所述经典光信号中包括的所述多个子经典光信号；其中，所述分波器满足以下条件：
    所述多个子经典光信号中包括波长处于C波段的子经典光信号，所述分波器为C波段分波器；
    所述多个子经典光信号中包括波长处于L波段的子经典光信号，所述分波器为L波段分波器；
    所述多个子经典光信号中包括波长处于C波段的子经典光信号和波长处于L波段的子经典光信号，所述分波器为C波段和L波段分波器。
  27. 如权利要求21至26任一权利要求所述的方法，其特征在于，存在多个不同波长的子量子光信号时：
    所述接收装置从所述耦合后光信号中确定出所述量子光信号之后，还包括：
    所述接收装置通过S波段分波器，对所述量子光信号进行分波处理，得到所述量子光信号中包括的所述多个子量子光信号。
  28. 如权利要求27所述的方法，其特征在于，所述S波段分波器的每个子带的带宽范围为0.1nm至5nm。
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