A circular-sided square microcavity laser etched a central hole has achieved chaos operation with a bandwidth of 20.8 GHz without external optical feedback or injection,in which the intensity probability distribution ...A circular-sided square microcavity laser etched a central hole has achieved chaos operation with a bandwidth of 20.8 GHz without external optical feedback or injection,in which the intensity probability distribution of a chaotic signal with a twopeak pattern was observed.Based on the self-chaotic microlaser,physical random numbers at 400 Gb/s were generated by extracting the four least significant bits without other complex post-processing methods.The solitary chaos laser and minimal post-processing have predicted a simpler and low-cost on-chip random number generator in the future.展开更多
“Inhibition of return”(IOR)was originally described in the field of spatial attention,but it has also been observed in random number generation tasks.Subjects showed a tendency of“repetition avoidance,”which can b...“Inhibition of return”(IOR)was originally described in the field of spatial attention,but it has also been observed in random number generation tasks.Subjects showed a tendency of“repetition avoidance,”which can be considered as equivalent to IOR in another cognitive domain.As temporal factors have been suspected to play an important role in random number generation,we aimed to examine how such factors might influence regularities such as repetition avoidance in random number generation tasks.Participants were instructed to verbally generate a sequence of numbers at a certain pace,that is,with either 0.5,1.5,3 or 4 s between each response.Each number in the sequence should have the same probability of appearance and should be independent from the others.However,it was observed that the human-generated sequences differed drastically from computersimulated pseudo-random sequences.The distribution of the repetition gap,which indicates how many different numbers are reported between two identical numbers in the generated sequences,showed a“three-phase”characteristic:a phase of avoidance of the same number,an oscillatory component for coming back to the same number,and finally an exponential decay of number selection frequencies.This three-phase characteristic was independent of the time interval between responses.These observations indicate an itembased process in random number generation,making a time-based control in this task rather unlikely as has been hypothetically assumed.展开更多
Quantum randomness amplification protocols have increasingly attracted attention tbr their tantastic ability to ampllI~, weak randomness to almost ideal randomness by utilizing quantum systems. Recently, a realistic n...Quantum randomness amplification protocols have increasingly attracted attention tbr their tantastic ability to ampllI~, weak randomness to almost ideal randomness by utilizing quantum systems. Recently, a realistic noise-tolerant randomness amplification protocol using a finite number of untrusted devices was proposed. The protocol has the composable security against non-signalling eavesdroppers and could produce a single bit of randomness from weak randomness sources, which is certified by the violation of certain Bell inequalities. However, the protocol has a non-ignorable limitation on the min- entropy of independent sources. In this paper, we further develop the randomness amplification method and present a novel quantum randomness amplification protocol based on an explicit non-malleable two independent-source randomness extractor, which could remarkably reduce the above-mentioned specific limitation. Moreover, the composable security of our improved protocol is also proposed. Our results could significantly expand the application range for practical quantum randomness amplification, and provide a new insight on the practical design method for randomness extraction.展开更多
Simultaneous bandwidth(BW) enhancement and time-delay signature(TDS) suppression of chaotic lasing over a wide range of parameters by mutually coupled semiconductor lasers(MCSLs) with random optical injection are prop...Simultaneous bandwidth(BW) enhancement and time-delay signature(TDS) suppression of chaotic lasing over a wide range of parameters by mutually coupled semiconductor lasers(MCSLs) with random optical injection are proposed and numerically investigated. The influences of system parameters on TDS suppression(characterized by autocorrelation function(ACF) and permutation entropy(PE) around characteristic time) and chaos BW are investigated. The results show that, with the increasing bias current, the ranges of parameters(detuning and injection strength) for the larger BW(> 20 GHz) are broadened considerably, while the parameter range for optimized TDS(< 0.1) is not shrunk obviously.Under optimized parameters, the system can simultaneously achieve two chaos outputs with enhanced BW(> 20 GHz)and perfect TDS suppression. In addition, the system can generate two-channel high-speed truly physical random number sequences at 200 Gbits/s for each channel.展开更多
This paper questions the generally accepted assumption that one can make a random choice that is independent of the rest of the universe. We give a general description of any setup that could be conceived to generate ...This paper questions the generally accepted assumption that one can make a random choice that is independent of the rest of the universe. We give a general description of any setup that could be conceived to generate random numbers. Based on the fact that the initial state of such setup together with its environment cannot be known, we show that the independence of its generated output cannot be guaranteed. Some consequences of this theoretical limitation are discussed.展开更多
Optical chaos generated by perturbing semiconductor lasers has been viewed,over recent decades,as an excellent entropy source for fast physical random bit generation(RBG)owing to its high bandwidth and large random fl...Optical chaos generated by perturbing semiconductor lasers has been viewed,over recent decades,as an excellent entropy source for fast physical random bit generation(RBG)owing to its high bandwidth and large random fluctuations.However,most optical-chaos-based random bit generators perform their quantization process in the electrical domain using electrical analog-to-digital converters,so their real-time rates in a single channel are severely limited at the level of Gb/s due to the electronic bottleneck.Here,we propose and experimentally demonstrate an all-optical method for RBG where chaotic pulses are quantized into a physical random bit stream in the all-optical domain by means of a length of highly nonlinear fiber.In our proof-of-concept experiment,a 10-Gb/s random bit stream is successfully generated on-line using our method.Note that the single-channel real-time rate is limited only by the chaos bandwidth.Considering that the Kerr nonlinearity of silica fiber with an ultrafast response of few femtoseconds is exploited for composing the key part of quantizing laser chaos,this scheme thus may operate potentially at much higher real-time rates than 100 Gb/s provided that a chaotic entropy source of sufficient bandwidth is available.展开更多
In this article,the random walking method is used to solve the steady linear convection-diffusion equation(CDE)with disc boundary condition.The integral solution corresponding to the random walking method is deduced a...In this article,the random walking method is used to solve the steady linear convection-diffusion equation(CDE)with disc boundary condition.The integral solution corresponding to the random walking method is deduced and the relationship between the diffusion coefficient of CDE and the intensity of the random diffusion motion is obtained.The random number generator for arbitrary axisymmetric disc boundary is deduced through the polynomial fitting and inverse transform sampling method.The proposed method is tested through two numerical cases.The results show that the random walking method can solve the steady linear CDE effectively.The influence of the parameters on the results is also studied.It is found that the error of the solution can be decreased by increasing the particle releasing rate and the total walking time.展开更多
Continuous variable quantum key distribution(CV-QKD)and continuous variable quantum random number generation(CV-QRNG)are critical technologies for secure communication and high-speed randomness generation,exploiting s...Continuous variable quantum key distribution(CV-QKD)and continuous variable quantum random number generation(CV-QRNG)are critical technologies for secure communication and high-speed randomness generation,exploiting shot-noise-limited coherent detection for their operation.Integrated photonic solutions are key to advancing these protocols,as they enable compact,scalable,and efficient system implementations.We introduce femtosecond laser micromachining(FLM)on borosilicate glass as a platform for producing photonic integrated circuits(PICs)realizing coherent detection suitable for quantum information processing.Employing off-chip detectors,we exploit the specific features of FLM to produce a PIC designed for CV-QKD and CV-QRNG applications.The PIC features fully adjustable optical components that achieve precise calibration and reliable operation under protocol-defined conditions.The device exhibits low insertion losses(≤1.28 d B),polarization-insensitive operation,and a common-mode rejection ratio exceeding 73 dB.These characteristics allowed the experimental realization of a source-device-independent CV-QRNG with a secure generation rate of 42.74 Gbit/s and a quadrature phase-shift-keying-based CV-QKD system achieving a secret key rate of 3.2 Mbit∕s.Our results highlight the potential of FLM technology as an integrated photonic platform,paving the way for scalable and high-performing quantum communication systems.展开更多
A ring of three unidirectionally coupled semiconductor lasers （RTUC-SLs） is used to generate broadband chaos with no pronounced time-delay （TD） signature. Using the autocorrelation function and pernmtation entropy...A ring of three unidirectionally coupled semiconductor lasers （RTUC-SLs） is used to generate broadband chaos with no pronounced time-delay （TD） signature. Using the autocorrelation function and pernmtation entropy as the TD measures, we demonstrate that under suitable coupling strength, the loss of the TD signature of the lasers in the RTUC-SL configuration is achieved both for the intensity and the phase. These findings should prove valuable for developing high-quality optical chaos for potential applications, such as chaos-based communica- tions and random number generation.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12274407,61935018,62122073,and 61874113)the Strategic Priority Research Program,Chinese Academy of Sciences(No.XDB43000000)。
文摘A circular-sided square microcavity laser etched a central hole has achieved chaos operation with a bandwidth of 20.8 GHz without external optical feedback or injection,in which the intensity probability distribution of a chaotic signal with a twopeak pattern was observed.Based on the self-chaotic microlaser,physical random numbers at 400 Gb/s were generated by extracting the four least significant bits without other complex post-processing methods.The solitary chaos laser and minimal post-processing have predicted a simpler and low-cost on-chip random number generator in the future.
基金National Natural Science Foundation of China,Grant/Award Numbers:31371018,31771213。
文摘“Inhibition of return”(IOR)was originally described in the field of spatial attention,but it has also been observed in random number generation tasks.Subjects showed a tendency of“repetition avoidance,”which can be considered as equivalent to IOR in another cognitive domain.As temporal factors have been suspected to play an important role in random number generation,we aimed to examine how such factors might influence regularities such as repetition avoidance in random number generation tasks.Participants were instructed to verbally generate a sequence of numbers at a certain pace,that is,with either 0.5,1.5,3 or 4 s between each response.Each number in the sequence should have the same probability of appearance and should be independent from the others.However,it was observed that the human-generated sequences differed drastically from computersimulated pseudo-random sequences.The distribution of the repetition gap,which indicates how many different numbers are reported between two identical numbers in the generated sequences,showed a“three-phase”characteristic:a phase of avoidance of the same number,an oscillatory component for coming back to the same number,and finally an exponential decay of number selection frequencies.This three-phase characteristic was independent of the time interval between responses.These observations indicate an itembased process in random number generation,making a time-based control in this task rather unlikely as has been hypothetically assumed.
基金Project supported by the National Natural Science Foundation of China(Grant No.61775185)
文摘Quantum randomness amplification protocols have increasingly attracted attention tbr their tantastic ability to ampllI~, weak randomness to almost ideal randomness by utilizing quantum systems. Recently, a realistic noise-tolerant randomness amplification protocol using a finite number of untrusted devices was proposed. The protocol has the composable security against non-signalling eavesdroppers and could produce a single bit of randomness from weak randomness sources, which is certified by the violation of certain Bell inequalities. However, the protocol has a non-ignorable limitation on the min- entropy of independent sources. In this paper, we further develop the randomness amplification method and present a novel quantum randomness amplification protocol based on an explicit non-malleable two independent-source randomness extractor, which could remarkably reduce the above-mentioned specific limitation. Moreover, the composable security of our improved protocol is also proposed. Our results could significantly expand the application range for practical quantum randomness amplification, and provide a new insight on the practical design method for randomness extraction.
基金Project supported by the Sichuan Science and Technology Program,China(Grant No.2019YJ0530)the Scientific Research Fund of Sichuan Provincial Education Department,China(Grant No.18ZA0401)+1 种基金the Innovative Training Program for College Student of Sichuan Normal University,China(Grant No.S20191063609)the National Natural Science Foundation of China(Grant No.61205079)。
文摘Simultaneous bandwidth(BW) enhancement and time-delay signature(TDS) suppression of chaotic lasing over a wide range of parameters by mutually coupled semiconductor lasers(MCSLs) with random optical injection are proposed and numerically investigated. The influences of system parameters on TDS suppression(characterized by autocorrelation function(ACF) and permutation entropy(PE) around characteristic time) and chaos BW are investigated. The results show that, with the increasing bias current, the ranges of parameters(detuning and injection strength) for the larger BW(> 20 GHz) are broadened considerably, while the parameter range for optimized TDS(< 0.1) is not shrunk obviously.Under optimized parameters, the system can simultaneously achieve two chaos outputs with enhanced BW(> 20 GHz)and perfect TDS suppression. In addition, the system can generate two-channel high-speed truly physical random number sequences at 200 Gbits/s for each channel.
文摘This paper questions the generally accepted assumption that one can make a random choice that is independent of the rest of the universe. We give a general description of any setup that could be conceived to generate random numbers. Based on the fact that the initial state of such setup together with its environment cannot be known, we show that the independence of its generated output cannot be guaranteed. Some consequences of this theoretical limitation are discussed.
基金the National Natural Science Foundation of China(62175177,U19A2076,61731014,61961136002,61927811,and 61805168)Natural Science Foundation of Shanxi Province(201901D211116,201901D211077)
文摘Optical chaos generated by perturbing semiconductor lasers has been viewed,over recent decades,as an excellent entropy source for fast physical random bit generation(RBG)owing to its high bandwidth and large random fluctuations.However,most optical-chaos-based random bit generators perform their quantization process in the electrical domain using electrical analog-to-digital converters,so their real-time rates in a single channel are severely limited at the level of Gb/s due to the electronic bottleneck.Here,we propose and experimentally demonstrate an all-optical method for RBG where chaotic pulses are quantized into a physical random bit stream in the all-optical domain by means of a length of highly nonlinear fiber.In our proof-of-concept experiment,a 10-Gb/s random bit stream is successfully generated on-line using our method.Note that the single-channel real-time rate is limited only by the chaos bandwidth.Considering that the Kerr nonlinearity of silica fiber with an ultrafast response of few femtoseconds is exploited for composing the key part of quantizing laser chaos,this scheme thus may operate potentially at much higher real-time rates than 100 Gb/s provided that a chaotic entropy source of sufficient bandwidth is available.
基金supported by the International Scientific and Technological Cooperation Program of China(Grant No.2011DFG13020)the China Postdoctoral Science Foundation(Grant No.2013M530043)the National Hi-Tech Research and Development Program of China("863"Project)(Grant No.2007AA05Z426)
文摘In this article,the random walking method is used to solve the steady linear convection-diffusion equation(CDE)with disc boundary condition.The integral solution corresponding to the random walking method is deduced and the relationship between the diffusion coefficient of CDE and the intensity of the random diffusion motion is obtained.The random number generator for arbitrary axisymmetric disc boundary is deduced through the polynomial fitting and inverse transform sampling method.The proposed method is tested through two numerical cases.The results show that the random walking method can solve the steady linear CDE effectively.The influence of the parameters on the results is also studied.It is found that the error of the solution can be decreased by increasing the particle releasing rate and the total walking time.
基金financially supported by European Union’s Horizon Europe research and innovation program under the project Quantum Secure Networks Partnership(QSNP)Grant Agreement No.101114043。
文摘Continuous variable quantum key distribution(CV-QKD)and continuous variable quantum random number generation(CV-QRNG)are critical technologies for secure communication and high-speed randomness generation,exploiting shot-noise-limited coherent detection for their operation.Integrated photonic solutions are key to advancing these protocols,as they enable compact,scalable,and efficient system implementations.We introduce femtosecond laser micromachining(FLM)on borosilicate glass as a platform for producing photonic integrated circuits(PICs)realizing coherent detection suitable for quantum information processing.Employing off-chip detectors,we exploit the specific features of FLM to produce a PIC designed for CV-QKD and CV-QRNG applications.The PIC features fully adjustable optical components that achieve precise calibration and reliable operation under protocol-defined conditions.The device exhibits low insertion losses(≤1.28 d B),polarization-insensitive operation,and a common-mode rejection ratio exceeding 73 dB.These characteristics allowed the experimental realization of a source-device-independent CV-QRNG with a secure generation rate of 42.74 Gbit/s and a quadrature phase-shift-keying-based CV-QKD system achieving a secret key rate of 3.2 Mbit∕s.Our results highlight the potential of FLM technology as an integrated photonic platform,paving the way for scalable and high-performing quantum communication systems.
基金supported by the National Natural Science Foundation of China(61274042)
文摘A ring of three unidirectionally coupled semiconductor lasers （RTUC-SLs） is used to generate broadband chaos with no pronounced time-delay （TD） signature. Using the autocorrelation function and pernmtation entropy as the TD measures, we demonstrate that under suitable coupling strength, the loss of the TD signature of the lasers in the RTUC-SL configuration is achieved both for the intensity and the phase. These findings should prove valuable for developing high-quality optical chaos for potential applications, such as chaos-based communica- tions and random number generation.
