Quantum random number generator based on electro-optical modulation

Abstract

The utility model discloses a quantum random number generator based on electro-optical modulation. The quantum random number generator comprises an ASE signal source, a sampling signal source, an electro-optical modulator MZM, a detection module and a post-processing module. The utility model discloses a quantum random number generator based on electro-optical modulation, which is characterized in that spontaneous radiation noise emitted by an ASE signal source and femtosecond ultrashort sampling pulse emitted by a sampling signal source enter an electro-optical modulator MZM together for nonlinear optical sampling, and an obtained sampling result is detected and quantized by a detection module; and the quantum random number enters the post-processing module to generate a final random number, so that a signal processing link is converted from an electric domain to an optical domain, the rate limitation of an electronic device is avoided, and the rate of generating the quantum random number is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to quantum random number generator and quantum password cloud technical field, concretely relates to a quantum random number generator based on electro -optical modulation. BACKGROUND

[0002] The electro -optical modulation technology relies on the regulation and control of electro -optical effect, realizes the dynamic adjustment to the light wave transmission characteristic. Specifically, the refractive index of electro -optical crystal changes under the action of external electric field, and then influence the propagation path and phase of light wave in the crystal interior, and this mechanism provides the basis for electro -optical modulator. Electro -optical modulator not only plays an indispensable role in the signal modulation of optical communication network, the data writing of optical storage system and precision optical measurement, but also shows the potential value in the construction of highly complex quantum information processing system.

[0003] Quantum random number generator (Quantum Random Number Generator, QRNG) is based on quantum effect, and is theoretically proved to have unpredictable characteristics. Quantum random number generation technology is based on the basic principles of quantum mechanics, and represents a revolutionary leap in the field of information security. Compared with the pseudo-random number generator based on algorithm construction and the classical physical random number generator relying on the principles of classical physics, quantum random number generator has incomparable advantages due to its inherent unpredictability and unconditional security.

[0004] However, the quantum random number generator currently faces the problem of electronic bottleneck in practical application. Due to the lagging development of analog-to-digital converter technology, it is difficult to make breakthrough progress in sampling rate, precision and analog input bandwidth, which directly restricts the generation speed and quantization quality of random number sequence, resulting in that the rate of quantum random number generated by quantum random number generator is not high enough. UTILITY MODEL CONTENT

[0005] The utility model discloses in order to solve the problem that the rate of quantum random number generated by quantum random number generator is not high enough, and proposes a quantum random number generator based on electro -optical modulation.

[0006] In order to achieve the above object, the technical scheme adopted by the utility model is as follows:

[0007] A quantum random number generator based on electro -optical modulation, including ASE signal source, sampling signal source, electro -optical modulator MZM, detection module and post-processing module;

[0008] The output end of ASE signal source, the output end of sampling signal source are connected with the different input end of electro -optical modulator MZM respectively, and the output end of electro -optical modulator MZM is connected with the input end of detection module, and the output end of detection module is connected with the input end of post-processing module.

[0009] In the above scheme, the spontaneous emission noise emitted by the ASE signal source and the femtosecond-level ultra-short sampling pulse emitted by the sampling signal source enter the electro-optical modulator MZM for nonlinear optical sampling, the sampling result is detected by the detection module, quantized, and then enters the post-processing module to generate the final random number, which realizes the conversion of the signal processing link from the electrical domain to the optical domain, avoids the rate limitation of electronic devices, and improves the rate of generating quantum random numbers.

[0010] Preferably, the ASE signal source comprises a superluminescent diode SLED, a band-pass filter Filter, an erbium-doped fiber amplifier EDFA, and an optical isolator ISO.

[0011] The output end of the superluminescent diode SLED is connected with the input end of the band-pass filter Filter, the output end of the band-pass filter Filter is connected with the input end of the erbium-doped fiber amplifier EDFA, the output end of the erbium-doped fiber amplifier EDFA is connected with the input end of the optical isolator ISO, and the output end of the optical isolator ISO is connected with the input end of the electro-optical modulator MZM.

[0012] Preferably, the sampling signal source comprises a mode-locked laser MLL, a first wavelength division demultiplexer DWDM1, a wavelength division multiplexer WDM, and a plurality of optical channels.

[0013] The output end of the mode-locked laser MLL is connected with the input end of the first wavelength division demultiplexer DWDM1, one end of each optical channel is respectively connected with different output ends of the first wavelength division demultiplexer DWDM1, the other end of each optical channel is respectively connected with different input ends of the wavelength division multiplexer WDM, and the output end of the wavelength division multiplexer WDM is connected with the input end of the electro-optical modulator MZM.

[0014] Each optical channel is respectively provided with an attenuator ATT, and each optical channel is used for transmitting optical signals of different wavelengths.

[0015] Preferably, the detection module comprises a second wavelength division demultiplexer and a plurality of detection units.

[0016] The output end of the electro-optical modulator MZM is connected with the input end of the second wavelength division demultiplexer, different output ends of the second wavelength division demultiplexer are respectively connected with the input ends of different detection units, and the output ends of the detection units are respectively connected with different input ends of the post-processing module.

[0017] Preferably, the detection unit comprises a photodetector PD, a transimpedance amplifier TIA, and an analog-to-digital converter ADC.

[0018] The input end of the photoelectric detector PD is connected with an output end of the second wavelength division multiplexer, the output end of the photoelectric detector PD is connected with an input end of the trans-impedance amplifier TIA, the output end of the trans-impedance amplifier TIA is connected with an input end of the analog-to-digital converter ADC, and the output end of the analog-to-digital converter ADC is connected with an input end of the post-processing module.

[0019] Preferably, the number of the detection units is equal to the number of the optical channels.

[0020] Preferably, the optical channels are 4.

[0021] Preferably, the delays of the 4 optical channels are 0, 23.8fs, 47.6fs and 71.4fs respectively.

[0022] Preferably, the center wavelengths of the 4 optical channels are 650.12nm, 651.72nm, 653.33nm and 654.94nm respectively.

[0023] Preferably, the bandwidth of the optical channels is 1.2nm.

[0024] The present application has the beneficial technical effects that:

[0025] The utility model provides a quantum random number generator based on electro -optical modulation, the spontaneous emission noise of ASE signal source is together with the femtosecond level ultrashort sampling pulse of sampling signal source and enters electro -optical modulator MZM and carries out nonlinear optical sampling, and the sampling result is detected quantization after the detection module, and enters the post -processing module and produces final random number, realizes the signal processing link from the electronic domain to the optical domain, avoids the rate limitation of electronic device, improves the rate of producing quantum random number. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is the whole structure schematic diagram of the utility model;

[0027] Figure 2 It is the structure schematic diagram of ASE signal source in the utility model. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical scheme and advantage of the utility model more clearly, the following combines embodiment to the utility model and carries out further detailed explanation, but the range of protection of the utility model is not limited to the following specific embodiment.

[0029] Embodiment 1

[0030] As Figure 1As shown, a quantum random number generator based on electro-optical modulation includes an ASE (Amplified Spontaneous Emission) signal source, a sampling signal source, an electro-optical modulator MZM, a detection module, and a post-processing module.

[0031] The output end of the ASE signal source and the output end of the sampling signal source are respectively connected with different input ends of the electro-optical modulator MZM, the output end of the electro-optical modulator MZM is connected with the input end of the detection module, and the output end of the detection module is connected with the input end of the post-processing module.

[0032] In the specific implementation process, the spontaneous emission noise emitted by the ASE signal source and the femtosecond-level ultra-short sampling pulse emitted by the sampling signal source enter the electro-optical modulator MZM for nonlinear optical sampling, the sampling result is quantized by the detection module, and then enters the post-processing module to generate the final random number, thereby realizing the conversion of the signal processing link from the electrical domain to the optical domain, avoiding the rate limitation of electronic devices, and improving the rate of generating quantum random numbers.

[0033] Embodiment 2

[0034] A quantum random number generator based on electro-optical modulation includes an ASE signal source, a sampling signal source, an electro-optical modulator MZM, a detection module, and a post-processing module.

[0035] The output end of the ASE signal source and the output end of the sampling signal source are respectively connected with different input ends of the electro-optical modulator MZM, the output end of the electro-optical modulator MZM is connected with the input end of the detection module, and the output end of the detection module is connected with the input end of the post-processing module.

[0036] In the specific implementation process, the electro-optical modulator MZM is made by using the electro-optical effect of an electro-optical crystal. The electro-optical effect refers to the change of the refractive index inside the crystal with the change of the applied electric field. The characteristics of the crystal light transmission inside the crystal change when the refractive index changes, which is equivalent to the modulation of the light transmission by the electric field.

[0037] The light wave propagating in the input waveguide is divided into two light waves with the same power through a 3dB waveguide coupler, and the two light waves continue to propagate in two straight waveguides with the same structure. Two straight waveguides are subjected to electric field with opposite polarity and equal size, so that the passing light wave is subjected to phase modulation. The branched light subjected to phase modulation is coherently synthesized at the second branch to realize intensity modulation.

[0038] Suppose a light wave is incident on the MZ modulator, and the light field distribution is:

[0039] E i = E0exp(jωt)

[0040] The phase difference that the input light undergoes in the two arms of the modulator is:

[0041]

[0042] where n e is the refractive index of the extraordinary light, γ 33 is the electro-optic coefficient of the crystal, L is the length of the modulating electrode, V is the electrode voltage, and G is the spacing between the modulating electrode and the ground electrode.

[0043] The form of the light wave output after the two light waves with phase difference are coherent at the branch can be calculated as:

[0044]

[0045] where Therefore, the output light intensity can be represented as:

[0046]

[0047] More specifically, as Figure 2 shown, the ASE signal source includes a superluminescent diode SLED, a bandpass filter Filter, an erbium-doped fiber amplifier EDFA, and an optical isolator ISO;

[0048] The output end of the superluminescent diode SLED is connected with the input end of the bandpass filter Filter, the output end of the bandpass filter Filter is connected with the input end of the erbium-doped fiber amplifier EDFA, the output end of the erbium-doped fiber amplifier EDFA is connected with the input end of the optical isolator ISO, and the output end of the optical isolator ISO is connected with the input end of the electro-optic modulator MZM.

[0049] In the specific implementation process, the superluminescent diode SLED is used as a high-performance light source, which can provide high-intensity and wide-spectrum continuous light output, and is based on the radiation enhancement mechanism under strong excitation, that is, under extremely high excitation density, the spontaneous radiation photons undergo stimulated amplification process, resulting in an avalanche increase in light intensity, which is rich in quantum amplified spontaneous emission noise, and can be used to generate high-speed quantum random numbers.

[0050] The light signal emitted by the superluminescent diode SLED has a center wavelength of 1550 nm, and after being filtered by the bandpass filter Filter with a center wavelength of 1550 nm and a bandwidth of 20 nm, it is amplified by the erbium-doped fiber amplifier EDFA and then enters the electro-optic modulator MZM for nonlinear optical sampling;

[0051] where the ASE noise satisfies the Bose-Einstein distribution:

[0052]

[0053] where n is the probability of counting n photons in the average detection time, defined as the inverse of the detector bandwidth, is the average number of photons in the same time interval;

[0054] While the ASE light field containing more independent modes can be expressed by M times degenerate Bose-Einstein distribution:

[0055]

[0056] where M is the mode number of the light field, Γ(x) is the gamma function, and n is the average number of photons in each mode.

[0057] Since the amplified spontaneous emission noise spectrum of the super-radiation light emitting diode (SLED) is wide, it is easy to saturate the detector, so a band-pass filter (Filter) is used for filtering operation.

[0058] More specifically, the sampling signal source comprises a mode-locked laser (MLL), a first wavelength division demultiplexer (DWDM1), a wavelength division multiplexer (WDM), and a plurality of optical channels; wherein

[0059] An output end of the mode-locked laser (MLL) is connected to an input end of the first wavelength division demultiplexer (DWDM1), one end of each optical channel is respectively connected to different output ends of the first wavelength division demultiplexer (DWDM1), the other end of each optical channel is respectively connected to different input ends of the wavelength division multiplexer (WDM), and an output end of the wavelength division multiplexer (WDM) is connected to an input end of an electro-optical modulator (MZM).

[0060] Each optical channel is provided with an attenuator (ATT), and each optical channel is used to transmit an optical signal of different wavelength.

[0061] In the specific implementation process, when the femtosecond (fs) ultra-low jitter optical pulse generated by the mode-locked laser (MLL) is used as a sampling clock, the jitter is 3-4 orders of magnitude lower than the traditional electronic clock, and the reduction of timing jitter will greatly improve the effective quantization resolution (i.e. effective number of bits (ENOB)) and the available input analog signal bandwidth.

[0062] More specifically, the detection module comprises a second wavelength division demultiplexer and a plurality of detection units; wherein

[0063] An output end of the electro-optical modulator (MZM) is connected to an input end of the second wavelength division demultiplexer, different output ends of the second wavelength division demultiplexer are respectively connected to input ends of different detection units, and output ends of each detection unit are respectively connected to different input ends of a post-processing module.

[0064] More specifically, the number of detection units is equal to the number of optical channels.

[0065] More specifically, the optical channels are 4.

[0066] More specifically, the delays of the 4 optical channels are 0, 23.8fs, 47.6fs, 71.4fs respectively.

[0067] In the specific implementation process, the mode-locked laser MLL emits pulsed laser with a wavelength of 650nm and a repetition frequency of 10Ghz. The laser emitted from the mode-locked laser MLL first passes through the first wavelength division demultiplexer DWDM1 for spectral slicing processing. Except for the first path, the other three paths each have a delay of 23.8fs, 47.6fs, and 71.4fs. Then, the laser passes through the wavelength division multiplexer WDM for beam combination and is input into the electro-optical modulator MZM for nonlinear optical sampling.

[0068] In the specific implementation process, the first wavelength division demultiplexer DWDM1 decomposes the optical pulse train from the mode-locked laser MLL into multiple optical channels with different wavelengths. Along each channel, the optical signal is given a different time delay. Subsequently, these delayed optical signals are combined by the wavelength division multiplexer WDM to form a series of composite optical pulse sequences for sampling. After this operation, the repetition rate of the pulses is significantly increased, and the increase factor is directly related to the number of wavelength division demultiplexing channels. In this embodiment, a four-channel configuration is used, so the final sequence has a repetition frequency that is four times the repetition frequency of the original mode-locked laser MLL.

[0069] The optical pulse sequence after this processing contains a variety of frequency components and can sample the target signal in a more precise and efficient manner. After sampling, the optical sequence needs to undergo a second wavelength division demultiplexer operation before reaching the post-processing stage, and is thus again decomposed into independent optical signal streams, each carrying its own frequency marker. After the photodetector PD completes the conversion from optical signal to electrical signal, the converted electrical signal is received by the analog-to-digital converter ADC for digital processing and data reconstruction. After post-processing and output of the final random sequence, a 40Gbit / s high-speed secure random sequence generation can be achieved.

[0070] More specifically, the center wavelengths of the 4 optical channels are 650.12nm, 651.72nm, 653.33nm, and 654.94nm respectively.

[0071] More specifically, the bandwidth of the optical channels is 1.2nm.

[0072] More specifically, the detection unit includes a photodetector PD, a transimpedance amplifier TIA, and an analog-to-digital converter ADC.

[0073] The input end of the photoelectric detector PD is connected with an output end of the second wavelength division multiplexer, the output end of the photoelectric detector PD is connected with an input end of the trans-impedance amplifier TIA, the output end of the trans-impedance amplifier TIA is connected with an input end of the analog-to-digital converter ADC, and the output end of the analog-to-digital converter ADC is connected with an input end of the post-processing module.

[0074] According to the disclosure and teaching of the above description, the skilled in the art can also change and modify the above embodiments. Therefore, the utility model is not limited to the specific embodiments disclosed and described above, and some modifications and changes of the utility model should fall within the protection scope of the claims of the utility model. In addition, although some specific terms are used in the specification, these terms are only for convenience and do not constitute any limitation on the utility model.

Claims

1. A quantum random number generator based on electro-optic modulation, characterized in that, It includes an ASE signal source, a sampling signal source, an electro-optic modulator (MZM), a detection module, and a post-processing module; The output terminals of the ASE signal source and the sampling signal source are respectively connected to different input terminals of the electro-optic modulator MZM. The output terminal of the electro-optic modulator MZM is connected to the input terminal of the detection module, and the output terminal of the detection module is connected to the input terminal of the post-processing module.

2. A quantum random number generator based on electro-optic modulation according to claim 1, characterized in that, The ASE signal source includes a superluminescent diode (SLED), a bandpass filter, an erbium-doped fiber amplifier (EDFA), and an optical isolator (ISO). The output terminal of the superluminescent diode (SLED) is connected to the input terminal of the bandpass filter (Filter), the output terminal of the bandpass filter (Filter) is connected to the input terminal of the erbium-doped fiber amplifier (EDFA), the output terminal of the EDFA is connected to the input terminal of the optical isolator (ISO), and the output terminal of the ISO is connected to the input terminal of the electro-optic modulator (MZM).

3. A quantum random number generator based on electro-optic modulation according to claim 1, characterized in that, The sampling signal source includes a mode-locked laser (MLL), a first wavelength division multiplexer (DWDM1), a wavelength division multiplexer (WDM), and multiple optical channels; among which... The output of the mode-locked laser MLL is connected to the input of the first wavelength division multiplexer DWDM1. One end of each optical channel is connected to a different output of the first wavelength division multiplexer DWDM1, and the other end of each optical channel is connected to a different input of the wavelength division multiplexer WDM. The output of the wavelength division multiplexer WDM is connected to the input of the electro-optic modulator MZM. Each optical channel is equipped with an attenuator (ATT), and each optical channel is used to transmit optical signals of different wavelengths.

4. A quantum random number generator based on electro-optic modulation according to claim 3, characterized in that, The detection module includes a second-wave demultiplexer and multiple detection units; wherein... The output of the electro-optic modulator MZM is connected to the input of the second wave demultiplexer. Different outputs of the second wave demultiplexer are connected to the inputs of different detection units, and the outputs of each detection unit are connected to different inputs of the post-processing module.

5. A quantum random number generator based on electro-optic modulation according to claim 4, characterized in that, The detection unit includes a photodetector (PD), a transimpedance amplifier (TIA), and an analog-to-digital converter (ADC). The input terminal of the photodetector PD is connected to one output terminal of the second wave demultiplexer, the output terminal of the photodetector PD is connected to the input terminal of the transimpedance amplifier TIA, the output terminal of the transimpedance amplifier TIA is connected to the input terminal of the analog-to-digital converter ADC, and the output terminal of the analog-to-digital converter ADC is connected to one input terminal of the post-processing module.

6. A quantum random number generator based on electro-optic modulation according to claim 4, characterized in that, The number of detection units is equal to the number of optical channels.

7. A quantum random number generator based on electro-optic modulation according to claim 6, characterized in that, There are four optical channels.

8. A quantum random number generator based on electro-optic modulation according to claim 7, characterized in that, The delays of the four optical channels are 0, 23.8 fs, 47.6 fs, and 71.4 fs, respectively.

9. A quantum random number generator based on electro-optic modulation according to claim 3, characterized in that, The center wavelengths of the four optical channels are 650.12nm, 651.72nm, 653.33nm, and 654.94nm, respectively.

10. A quantum random number generator based on electro-optic modulation according to any one of claims 3-9, characterized in that, The bandwidth of the optical channel is 1.2nm.

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