Quantum random number generator based on semiconductor optical amplifier

Abstract

The utility model discloses a quantum random number generator based on a semiconductor optical amplifier. The quantum random number generator comprises an entropy source, an optical sampling module, a quantization module and a post-processing module, the optical sampling module comprises a sampling optical signal module and a polarization rotation optical sampling module based on a semiconductor optical amplifier. The utility model discloses a quantum random number generator based on a semiconductor optical amplifier, which realizes all-optical pulse sampling through a polarization rotation optical sampling module based on the polarization rotation nonlinear effect of the semiconductor optical amplifier, and can effectively improve the generation rate of quantum random numbers and effectively reduce the driving power. Only the low-speed analog-to-digital converter can be adopted for quantization without influencing the system generation rate, the system cost is reduced, and the method has high processing speed and practical value.

Description

Technical Field

[0001] The utility model relates to the field of quantum random number generator equipment, in particular to a quantum random number generator based on a semiconductor optical amplifier. Background Art

[0002] Optical signal processing technology based on semiconductor materials has attracted wide interest in the field of optical communications due to its unique advantages. Semiconductor optical amplifiers (SOAs) have the advantages of broadband amplification, fast response, adjustable gain, high gain, and integration, as well as significant nonlinear effects. By utilizing the nonlinear polarization rotation effect in semiconductor optical amplifiers, various all-optical digital signal processing functions can be realized, including wavelength conversion, optical switches, optical caches, optical logic gates, optical regeneration, and optical domain all-optical sampling.

[0003] Existing quantum random number generators usually have a structure of electrical sampling of optical signals. However, unfavorable factors such as timing jitter in electronic devices will affect their quantization accuracy, sampling rate and analog input bandwidth, becoming an important factor limiting the QRNG rate. There are new challenges in meeting the demand for increasing the QRNG rate.

[0004] Therefore, it is necessary to improve the existing technology and propose a quantum random number generator with a higher QRNG rate. Utility Model Content

[0005] In order to solve the problem of limited rate of existing quantum random number generators, the utility model proposes a quantum random number generator based on a semiconductor optical amplifier.

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

[0007] A quantum random number generator based on a semiconductor optical amplifier, comprising an entropy source, an optical sampling module, a quantization module and a post-processing module;

[0008] The optical sampling module includes a sampling optical signal module and a polarization rotation optical sampling module based on a semiconductor optical amplifier;

[0009] The output end of the entropy source and the output end of the sampling optical signal module are respectively connected to the input end of the polarization rotation optical sampling module, the output end of the polarization rotation optical sampling module is connected to the input end of the quantization module, and the output end of the quantization module is connected to the input end of the post-processing module.

[0010] In the above scheme, all-optical pulse sampling is realized through the polarization rotation optical sampling module based on the polarization rotation nonlinear effect of the semiconductor optical amplifier, which can effectively improve the generation rate of quantum random numbers and effectively reduce the driving power. Only a low-speed analog-to-digital converter can be used for quantization without affecting the system generation rate, reducing the system cost, and having high processing speed and practical value.

[0011] Preferably, the entropy source comprises a superluminescent diode and an optical isolator;

[0012] The output end of the superluminescent diode is connected to the input end of the polarization rotation light sampling module through an optical isolator.

[0013] In the above scheme, a superluminescent diode is used to generate an amplified spontaneous emission noise signal as signal light, and wavelength division multiplexing can be used to perform multi-channel signal processing to effectively improve the QRNG rate.

[0014] Preferably, it also includes a circulator;

[0015] The output end of the entropy source is connected to the first port of the circulator, the output end of the sampling optical signal module is connected to the second port of the circulator, and the input end of the polarization rotation optical sampling module is connected to the third port of the circulator.

[0016] Preferably, the sampling optical signal module includes a mode-locked laser, a first optical fiber coupler, a first bandpass filter, a second bandpass filter, a wavelength division multiplexer and a first polarization controller;

[0017] The output end of the mode-locked laser is connected to the input end of the first optical fiber coupler, the input end of the first bandpass filter and the input end of the second bandpass filter are respectively connected to different output ends of the first optical fiber coupler, the output end of the first bandpass filter and the output end of the second bandpass filter are respectively connected to different input ends of the wavelength division multiplexer, the output end of the wavelength division multiplexer is connected to the input end of the first polarization controller, and the output end of the first polarization controller is connected to the second port of the circulator.

[0018] In the above scheme, a femtosecond pulse is generated by a mode-locked laser as a sampling pulse signal, which has lower timing jitter and effectively improves the sampling speed.

[0019] Preferably, the polarization rotation light sampling module comprises a semiconductor optical amplifier, a second polarization controller, a second optical fiber coupler, a third bandpass filter, a fourth bandpass filter, a first polarization beam splitter, and a second polarization beam splitter;

[0020] The input end of the semiconductor optical amplifier is connected to the third port of the circulator, the output end of the semiconductor optical amplifier is connected to the input end of the second polarization controller, the output end of the second polarization controller is connected to the input end of the second optical fiber coupler, the input end of the third bandpass filter and the input end of the fourth bandpass filter are respectively connected to different output ends of the second optical fiber coupler, and the output end of the third bandpass filter and the output end of the fourth bandpass filter are respectively connected to different input ends of the quantization module through the first polarization beam splitter and the second polarization beam splitter.

[0021] Preferably, the quantization module includes a first photodetector, a second photodetector, a first analog-to-digital converter, and a second analog-to-digital converter;

[0022] The output end of the third bandpass filter is connected to the input end of the first photodetector through the first polarization beam splitter, the output end of the fourth bandpass filter is connected to the input end of the second photodetector through the second polarization beam splitter, the output end of the first photodetector is connected to the input end of the first analog-to-digital converter, the output end of the second photodetector is connected to the input end of the second analog-to-digital converter, and the output end of the first analog-to-digital converter and the output end of the second analog-to-digital converter are respectively connected to different input ends of the post-processing module.

[0023] Preferably, the quantization module further includes a third photodetector;

[0024] The third photodetector is used to detect the output of the wavelength division multiplexer and output the result as the clock signal of the first analog-to-digital converter and the second analog-to-digital converter.

[0025] Preferably, the superluminescent diode is used to emit a wide spectrum signal with a central wavelength of 1550 nm.

[0026] Preferably, the mode-locked laser is used to emit pulsed laser with a wavelength of 780 nm.

[0027] Preferably, the post-processing module is FPGA.

[0028] Beneficial technical effects of the utility model:

[0029] The utility model provides a quantum random number generator based on a semiconductor optical amplifier. Through a polarization rotation optical sampling module based on the polarization rotation nonlinear effect of the semiconductor optical amplifier, all-optical pulse sampling is realized, which can effectively improve the generation rate of quantum random numbers and effectively reduce the driving power. Only a low-speed analog-to-digital converter can be used for quantization without affecting the system generation rate, reducing the system cost, and having high processing speed and practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1This is a schematic diagram of module connection in one embodiment of the utility model;

[0031] Figure 2 This is a schematic diagram of the overall structure of another embodiment of the utility model;

[0032] Wherein: 100, entropy source; 101, superluminescent diode; 102, optical isolator; 200, optical sampling module; 210, sampling optical signal module; 211, mode-locked laser; 212, first fiber coupler; 213, first bandpass filter; 214, second bandpass filter; 215, wavelength division multiplexer; 216, first polarization controller; 220, polarization rotation optical sampling module; 221, semiconductor optical amplifier; 222, second polarization controller; 223, second fiber coupler; 224, third bandpass filter; 225, fourth bandpass filter; 226, first polarization beam splitter; 227, second polarization beam splitter; 300, quantization module; 301, first photodetector; 302, second photodetector; 303, first analog-to-digital converter; 304, second analog-to-digital converter; 305, third photodetector; 400, post-processing module; 500, circulator. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the utility model more clearly understood, the utility model is further described in detail below in conjunction with embodiments, but the scope of protection claimed in the utility model is not limited to the following specific embodiments. Example

[0034] like Figure 1 As shown, a quantum random number generator based on a semiconductor optical amplifier includes an entropy source, an optical sampling module, a quantization module and a post-processing module;

[0035] The optical sampling module includes a sampling optical signal module and a polarization rotation optical sampling module based on a semiconductor optical amplifier;

[0036] The output end of the entropy source and the output end of the sampling optical signal module are respectively connected to the input end of the polarization rotation optical sampling module, the output end of the polarization rotation optical sampling module is connected to the input end of the quantization module, and the output end of the quantization module is connected to the input end of the post-processing module.

[0037] In the specific implementation process, all-optical pulse sampling is realized through the polarization rotation optical sampling module based on the polarization rotation nonlinear effect of the semiconductor optical amplifier, which can effectively improve the generation rate of quantum random numbers and effectively reduce the driving power. Only a low-speed analog-to-digital converter can be used for quantization without affecting the system generation rate, reducing the system cost, and has high processing speed and practical value. Example

[0038] More specifically, Figure 2 As shown, the entropy source includes a superluminescent diode and an optical isolator;

[0039] The output end of the superluminescent diode is connected to the input end of the polarization rotation light sampling module through an optical isolator.

[0040] In the specific implementation process, a superluminescent diode is used to generate an amplified spontaneous emission noise signal as the signal light, and wavelength division multiplexing can be used to perform multi-channel signal processing to effectively improve the QRNG rate.

[0041] More specifically, it also includes a circulator;

[0042] The output end of the entropy source is connected to the first port of the circulator, the output end of the sampling optical signal module is connected to the second port of the circulator, and the input end of the polarization rotation optical sampling module is connected to the third port of the circulator.

[0043] More specifically, the sampling optical signal module includes a mode-locked laser, a first optical fiber coupler, a first bandpass filter, a second bandpass filter, a wavelength division multiplexer and a first polarization controller;

[0044] The output end of the mode-locked laser is connected to the input end of the first optical fiber coupler, the input end of the first bandpass filter and the input end of the second bandpass filter are respectively connected to different output ends of the first optical fiber coupler, the output end of the first bandpass filter and the output end of the second bandpass filter are respectively connected to different input ends of the wavelength division multiplexer, the output end of the wavelength division multiplexer is connected to the input end of the first polarization controller, and the output end of the first polarization controller is connected to the second port of the circulator.

[0045] In the specific implementation process, the femtosecond ultrashort pulse signal emitted by the mode-locked laser is divided into two optical signals through the first optical fiber coupler, one of which is filtered by the first bandpass filter, and the other is filtered by the second bandpass filter. The two filtered optical signals are combined by the wavelength division multiplexer and modulated by the first polarization controller to obtain a sampling pulse signal; the femtosecond pulse generated by the mode-locked laser as the sampling pulse signal has lower timing jitter, which effectively improves the sampling speed.

[0046] More specifically, the polarization rotation optical sampling module includes a semiconductor optical amplifier, a second polarization controller, a second optical fiber coupler, a third bandpass filter, a fourth bandpass filter, a first polarization beam splitter, and a second polarization beam splitter;

[0047] The input end of the semiconductor optical amplifier is connected to the third port of the circulator, the output end of the semiconductor optical amplifier is connected to the input end of the second polarization controller, the output end of the second polarization controller is connected to the input end of the second optical fiber coupler, the input end of the third bandpass filter and the input end of the fourth bandpass filter are respectively connected to different output ends of the second optical fiber coupler, and the output end of the third bandpass filter and the output end of the fourth bandpass filter are respectively connected to different input ends of the quantization module through the first polarization beam splitter and the second polarization beam splitter.

[0048] In the specific implementation process, the amplified spontaneous radiation noise signal and the sampling pulse signal are first subjected to nonlinear sampling by a semiconductor optical amplifier, and the waveform of the amplified spontaneous radiation noise signal is copied to the envelope of the sampling pulse signal to realize high-speed all-optical pulse sampling of the amplified spontaneous radiation noise signal. Then, the result of the nonlinear sampling is modulated by a second polarization controller and then divided into two optical signals by a second optical fiber coupler, one of which is filtered by a third bandpass filter and mode-merged by a first polarization beam splitter in turn to obtain a first optical sampling result; the other optical signal is filtered by a fourth bandpass filter and mode-merged by a second polarization beam splitter in turn to obtain a second optical sampling result.

[0049] More specifically, the quantization module includes a first photodetector, a second photodetector, a first analog-to-digital converter, and a second analog-to-digital converter;

[0050] The output end of the third bandpass filter is connected to the input end of the first photodetector through the first polarization beam splitter, the output end of the fourth bandpass filter is connected to the input end of the second photodetector through the second polarization beam splitter, the output end of the first photodetector is connected to the input end of the first analog-to-digital converter, the output end of the second photodetector is connected to the input end of the second analog-to-digital converter, and the output end of the first analog-to-digital converter and the output end of the second analog-to-digital converter are respectively connected to different input ends of the post-processing module.

[0051] In the specific implementation process, since the optical sampling module has already sampled the signal light at high speed, the quantization module only needs a low-cost, low-speed analog-to-digital converter for quantization; the front end of the analog-to-digital converter in this embodiment does not include a sample-and-hold circuit, so it does not have a sampling function, and only quantizes the random pulses from the optical sampling module with ultra-low timing jitter.

[0052] More specifically, the quantization module further includes a third photodetector;

[0053] The third photodetector is used to detect the output of the wavelength division multiplexer and output the result as the clock signal of the first analog-to-digital converter and the second analog-to-digital converter.

[0054] More specifically, the superluminescent diode is used to emit a wide spectrum signal with a central wavelength of 1550 nm.

[0055] In the specific implementation process, the central wavelengths corresponding to the third bandpass filter and the fourth bandpass filter are 1549nm and 1551nm respectively, with a width of 2nm, and the sampled optical signal is divided into two paths, and only the signal light is retained. The wide spectrum of the amplified spontaneous emission noise (ASE) noise is conducive to the use of parallel processing schemes. In this embodiment, there are only two parallel modes. In actual use, a dense wavelength division multiplexer can be used to divide the spectrum of the pulse light and the detection light according to specific needs to achieve multi-path expansion, which can greatly improve the generation rate of QRNG.

[0056] More specifically, the mode-locked laser is used to emit a pulsed laser with a wavelength of 780nm and a repetition frequency of 10GHz, which is divided into two paths through the first optical fiber coupler. The central wavelengths of the first bandpass filter and the second bandpass filter are 739nm and 741nm respectively, and the filter width is 2nm. One path does not require delay, and the other path is delayed. After filtering, the optical signal enters the wavelength division multiplexer for beam combining. The repetition frequency of the combined optical signal is twice the original, which is 20GHz, and then input into the semiconductor optical amplifier for nonlinear sampling, thereby realizing the sampling of the input laser. Finally, the pulsed laser of the mode-locked laser is filtered out through the third bandpass filter and the fourth bandpass filter, and only the sampled detection beam is retained.

[0057] In the specific implementation process, when the femtosecond (fs) ultra-low jitter optical pulses generated by the mode-locked laser are used as sampling clocks, the jitter is 3-4 orders of magnitude lower than that of traditional electronic clocks. The reduction in timing jitter will greatly improve the effective quantization resolution (i.e., effective number of bits ENOB) and the available input analog signal bandwidth.

[0058] More specifically, the post-processing module is FPGA.

[0059] In the specific implementation process, the quantization result is processed by the XOR algorithm through FPGA, so as to output the final random binary sequence.

[0060] According to the disclosure and teaching of the above specification, the technicians in the field of the utility model can also change and modify the above implementation. Therefore, the utility model is not limited to the specific implementation methods disclosed and described above, and some modifications and changes to the utility model should also fall within the scope of protection of the claims of the utility model. In addition, although some specific terms are used in this specification, these terms are only for convenience and do not constitute any limitation to the utility model.

Claims

1. A quantum random number generator based on a semiconductor optical amplifier, characterized in that: It includes entropy source, light sampling module, quantization module and post-processing module; The optical sampling module includes a sampling optical signal module and a polarization rotation optical sampling module based on a semiconductor optical amplifier; The output end of the entropy source and the output end of the sampling optical signal module are respectively connected to the input end of the polarization rotation optical sampling module, the output end of the polarization rotation optical sampling module is connected to the input end of the quantization module, and the output end of the quantization module is connected to the input end of the post-processing module.

2. A quantum random number generator based on a semiconductor optical amplifier according to claim 1, characterized in that: The entropy source includes a superluminescent diode and an optical isolator; The output end of the superluminescent diode is connected to the input end of the polarization rotation light sampling module through an optical isolator.

3. A quantum random number generator based on a semiconductor optical amplifier according to claim 1, characterized in that: Also included is a circulator; The output end of the entropy source is connected to the first port of the circulator, the output end of the sampling optical signal module is connected to the second port of the circulator, and the input end of the polarization rotation optical sampling module is connected to the third port of the circulator.

4. A quantum random number generator based on a semiconductor optical amplifier according to claim 3, characterized in that: The sampling optical signal module includes a mode-locked laser, a first optical fiber coupler, a first bandpass filter, a second bandpass filter, a wavelength division multiplexer and a first polarization controller; The output end of the mode-locked laser is connected to the input end of the first optical fiber coupler, the input end of the first bandpass filter and the input end of the second bandpass filter are respectively connected to different output ends of the first optical fiber coupler, the output end of the first bandpass filter and the output end of the second bandpass filter are respectively connected to different input ends of the wavelength division multiplexer, the output end of the wavelength division multiplexer is connected to the input end of the first polarization controller, and the output end of the first polarization controller is connected to the second port of the circulator.

5. A quantum random number generator based on a semiconductor optical amplifier according to claim 4, characterized in that: The polarization rotation light sampling module includes a semiconductor optical amplifier, a second polarization controller, a second fiber coupler, a third bandpass filter, a fourth bandpass filter, a first polarization beam splitter and a second polarization beam splitter; The input end of the semiconductor optical amplifier is connected to the third port of the circulator, the output end of the semiconductor optical amplifier is connected to the input end of the second polarization controller, the output end of the second polarization controller is connected to the input end of the second optical fiber coupler, the input end of the third bandpass filter and the input end of the fourth bandpass filter are respectively connected to different output ends of the second optical fiber coupler, and the output end of the third bandpass filter and the output end of the fourth bandpass filter are respectively connected to different input ends of the quantization module through the first polarization beam splitter and the second polarization beam splitter.

6. A quantum random number generator based on a semiconductor optical amplifier according to claim 5, characterized in that: The quantization module includes a first photodetector, a second photodetector, a first analog-to-digital converter, and a second analog-to-digital converter; The output end of the third bandpass filter is connected to the input end of the first photodetector through the first polarization beam splitter, the output end of the fourth bandpass filter is connected to the input end of the second photodetector through the second polarization beam splitter, the output end of the first photodetector is connected to the input end of the first analog-to-digital converter, the output end of the second photodetector is connected to the input end of the second analog-to-digital converter, and the output end of the first analog-to-digital converter and the output end of the second analog-to-digital converter are respectively connected to different input ends of the post-processing module.

7. A quantum random number generator based on a semiconductor optical amplifier according to claim 6, characterized in that: The quantization module also includes a third photodetector; The third photodetector is used to detect the output of the wavelength division multiplexer and output the result as the clock signal of the first analog-to-digital converter and the second analog-to-digital converter.

8. A quantum random number generator based on a semiconductor optical amplifier according to claim 2, characterized in that: The superluminescent diode is used to emit a wide spectrum signal with a central wavelength of 1550nm.

9. A quantum random number generator based on a semiconductor optical amplifier according to claim 4, characterized in that: The mode-locked laser is used to emit pulsed laser with a wavelength of 780 nm.

10. A quantum random number generator based on a semiconductor optical amplifier according to claim 1, characterized in that: The post-processing module is FPGA.

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