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Chaotic time-delay signature suppression using quantum noise

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arXiv 2021年

作者： Guo, Yanqiang Fang, Xin Zhang, Haojie Zhao, Tong Virte, Martin Guo, Xiaomin Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan030024 China State Key Laboratory of Cryptology Beijing100878 China Brussels Photonics Department of Applied Physics and Photonics Vrije Universiteit Brussel Brussels1050 Belgium

Time-delay signature (TDS) suppression of semiconductor lasers with external optical feedback is necessary to ensure security of chaos-based secure communications. Here we numerically and experimenttally demonstrate a technique to effectively suppress the TDS of chaotic laser using quantum noise. The TDS and dynamical complexity are quantified using the autocorrelation function and normalized permutation entropy at the feedback delay time, respectively. Quantum noise from quadrature fluctuations of vacuum state is prepared through balanced homodyne measurement. The effects of strength and bandwidth of quantum noise on chaotic TDS suppression and complexity enhancement are investigated numerically and experimentally. Compared to the original dynamics, the TDS of this quantum-noise improved chaos is sup-pressed up to 94% and the bandwidth suppression ratio of quantum noise to chaotic laser is 1:25. The experiment agrees well with the theory. The improved chaotic laser is potentially beneficial to chaos-based random number generation and secure communication. Copyright © 2021, The Authors. All rights reserved.

关键词： Time delay

Photon statistics and bunching of a chaotic semiconductor laser

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arXiv 2018年

作者： Yanqiang, G.U.O. Peng, Chunsheng Yulin, J.I. Pu, L.I. Yuanyuan, G.U.O. Xiaomin, G.U.O. Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan University of Technology Taiyuan030024 China Institute of Optoelectronic Engineering College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan030024 China

The photon statistics and bunching of a semiconductor laser with external optical feedback are investigated experimentally and theoretically. In a chaotic regime, the photon number distribution is measured and undergoes a transition from Bose-Einstein distribution to Poisson distribution with increasing the mean photon number. The second order degree of coherence decreases gradually from 2 to 1. Based on Hanbury Brown-Twiss scheme, pronounced photon bunching is observed experimentally for various injection currents and feedback strengths, which indicates the randomness of the associated emission light. Near-threshold injection currents and strong feedback strengths modify exactly the laser performance to be more bunched. The macroscopic chaotic dynamics is confirmed simultaneously by high-speed analog detection. The theoretical results qualitatively agree with the experimental results. It is potentially useful to extract randomness and achieve desired entropy source for random number generator and imaging science by quantifying the control parameters. Copyright © 2018, The Authors. All rights reserved.

关键词： Random number generation

Chaotic brillouin optical correlation domain analysis

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arXiv 2017年

作者： Zhang, Jianzhong Zhang, Mingtao Zhang, Mingjiang Yi, L.I.U. Feng, Changkun Wang, Yahui Wang, Yuncai Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan University of Technology Taiyuan030024 China Institute of Optoelectronic Engineering College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan030024 China

We propose and experimentally demonstrate a chaotic Brillouin optical correlation-domain analysis (BOCDA) system for distributed fiber sensing. The utilization of the chaotic laser with low coherent state ensures high spatial resolution. The experimental results demonstrate a 3.92-cm spatial resolution over a 906-m measurement range. The uncertainty in the measurement of the local Brillouin frequency shift is ＋ 1.2 MHz. The measurement signal-to-noise ratio is given, which is agreement with the theoretical value. © 2017 Optical Society of America Copyright © 2017, The Authors. All rights reserved.

关键词： Signal to noise ratio

Noise-induced dynamics and photon statistics in bimodal quantum-dot micropillar lasers

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arXiv 2023年

作者： Guo, Yanqiang Zhang, Jianfei Guo, Xiaomin Reitzenstein, Stephan Xiao, Liantuan Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education College of Physics Taiyuan University of Technology Taiyuan030024 China State Key Laboratory of Cryptology Beijing100878 China Institut für Festkörperphysik Technical University of Berlin Hardenbergstr. 36 BerlinD-10623 Germany

Emission characteristics of quantum-dot micropillar lasers are located at the intersection of nanophotonics and nonlinear dynamics, which provides an ideal platform for studying the optical interface between classical and quantum systems. In this work, a noise-induced bimodal quantum-dot micropillar laser with orthogonal dual-mode outputs is modeled, and nonlinear dynamics, stochastic mode jumping and quantum statistics with the variation of stochastic noise intensity are investigated. Noise-induced effects lead to the emergence of two intensity bifurcation points for the strong and the weak mode, and the maximum output power of the strong mode becomes larger as the noise intensity increases. The anti-correlation of the two modes reaches the maximum at the second intensity bifurcation point. The dual-mode stochastic jumping frequency and effective bandwidth can exceed 100 GHz and 30 GHz under the noise-induced effect. Moreover, the noise-induced photon correlations of both modes simultaneously exhibit super-thermal bunching effects (g(2)(0) > 2) in the low injection current region. The g(2)(0)-value of the strong mode can reach over 6 in the high injection current region. Photon bunching (g(2)(0) > 1) of both modes is observed over a wide range of noise intensities and injection currents. In the presence of the noise-induced effect, the photon number distribution of the strong or the weak mode is a mixture of Bose-Einstein and Poisson distributions. As the noise intensity increases, the photon number distribution of the strong mode is dominated by the Bose-Einstein distribution, and the proportion of the Poisson distribution is increased in the high injection current region, while that of the weak mode is reduced. Our results contribute to the development preparation of super-bunching quantum integrated light sources for improving the spatiotemporal resolution of quantum sensing measurements and enhancing the security of optical communication. Copyright © 2023, The

关键词： Dynamics

Enhancing quantum entropy in vacuum-based quantum random number generator

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arXiv 2018年

作者： Guo, Xiaomin Liu, Ripeng Li, Pu Cheng, Chen Wu, Mingchuan Guo, Yanqiang Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan University of Technology Taiyuan030024 China Institute of Optoelectronic Engineering College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan030024 China

Information-theoretically provable unique true random numbers, which cannot be correlated or controlled by an attacker, can be generated based on quantum measurement of vacuum state and universal-hashing randomness extraction. Quantum entropy in the measurements decides the quality and security of the random number generator. At the same time, it directly determine the extraction ratio of true randomness from the raw data, in other words, it affects quantum random numbers generating rate obviously. In this work, considering the effects of classical noise, the best way to enhance quantum entropy in the vacuum-based quantum random number generator is explored in the optimum dynamical analog-digital converter (ADC) range scenario. The influence of classical noise excursion, which may be intrinsic to a system or deliberately induced by an eavesdropper, on the quantum entropy is derived. We propose enhancing local oscillator intensity rather than electrical gain for noise-independent amplification of quadrature fluctuation of vacuum state. Abundant quantum entropy is extractable from the raw data even when classical noise excursion is large. Experimentally, an extraction ratio of true randomness of 85.3% is achieved by finite enhancement of the local oscillator power when classical noise excursions of the raw data is obvious. Copyright © 2018, The Authors. All rights reserved.

关键词： Quantum theory

86-Gb/s optical chaos communication over 100-km fiber transmission using semiconductor lasers

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86-Gb/s optical chaos communication over 100-km fiber transm...

49th European Conference on Optical Communications (ECOC 2023)

作者： X. Mao X. Fan L. Wang S. Fu Y. Wang A. Wang Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan 030024 People's Republic of China School of Information Engineering Guangdong University of Technology Guangzhou 510006 People's Republic of China

An optical-chaos secure communication of 86-Gb/s 16-ary QAM signal over 100-km fiber transmission is experimentally demonstrated under the 20%-overhead SD-FEC BER threshold of 2.0×10-2 by using wideband chaos syn...

ISBN: (数字)9781839539268

关键词：

Trimer superfluid induced by photoassocation on the state-dependent optical lattice

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Physical Review A 2014年第3期90卷 033622-033622页

作者： Wanzhou Zhang Ran Li W. X. Zhang C. B. Duan T. C. Scott College of Physics and Optoelectronics Taiyuan University of Technology Shanxi 030024 China Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan University of Technology Shanxi 030024 China Center for Applied Physics and Technology Peking University Beijing 100871 China College of Science Chang an University Xian 710064 China

We use the mean-field method, the quantum Monte Carlo method and the density-matrix-renormalization-group method to study the trimer superfluid phase and the quantum phase diagram of the Bose-Hubbard model in a one-dimensional optical lattice, with an explicit trimer-tunneling term. Theoretically, we derive the explicit trimer hopping terms, such as ai3†aj3, by the Schrieffer-Wolf transformation. In practice, the trimer superfluid described by these terms is driven by photoassociation. The phase transition between the trimer superfluid phase and other phases are also studied. Without the on-site interaction, the phase transition between the trimer superfluid phase and the Mott insulator phase is continuous. Turning on the on-site interaction, the phase transitions are first order with Mott insulators of atoms filling 1 and 2. With nonzero atom tunneling, the phase transition is first order from the atom superfluid to the trimer superfluid. In the trimer superfluid phase, the winding numbers can be divided by three without any remainder. The power-law decay exponent is 1/2 for the nondiagonal correlation ai†3aj3, i.e., the same as the exponent of the correlation ai†aj in hardcore bosons. The density-dependent atom-tunneling term ni2ai†aj and pair-tunneling term niai†2aj2 are also studied. With these terms, the phase transition from the empty phase to atom superfluid is first order and different from the cases without the density-dependent terms. The effects of finite three-body interactions and finite temperatures are also studied. Our results will be helpful in realizing the trimer superfluid by a cold-atom experiment.

关键词： OPTICAL lattices SUPERFLUIDITY QUANTUM Monte Carlo method RENORMALIZATION group DENSITY matrices MEAN field theory

Stability Enhancement of BOTDR Strain Sensing system by Using SOA-Based-Gain-Switched Modulation

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Stability Enhancement of BOTDR Strain Sensing System by Usin...

Optoelectronics Global Conference (OGC)

作者： Changshuo Liang Zeyu Ji Zheng Fang Qing Bai Yu Wang Xin Liu Baoquan Jin Key Laboratory of Advanced Transducers and Intelligent Control Systems Ministry of Education Taiyuan University of Technology Taiyuan China State Key Laboratory of Coal and CBM Co-mining Shanxi Jincheng Anthracite Mine Group Co. Ltd. Jincheng China

ISBN: (数字)9781728198606

ISBN: (纸本)9781728198613

Stable extinction ratio (ER) of the probe pulse is crucial to the measurement stability of Brillouin Optical Time-Domain Reflectometry (BOTDR). In this paper, a dynamic and continuous ER measurement scheme is proposed to evaluate the ER stability. Besides, a modified optical pulse modulation scheme based on gain switch is proposed to replace the conventional electric-optic modulation (EOM), aiming at enhancing the stability of BOTDR strain sensing system. The gain switch utilizes semiconductor optical amplifier (SOA) to generate probe pulse with the higher and more stable ER. Experiment results in 4 hours show the improvement of the ER stability with the proposed gain-switched modulation, which further improves the stability of BOTDR strain sensing system.

关键词： Modulation Erbium Optical switches Optical fibers Optical fiber sensors Optical variables measurement Optical pulses

Evaluating entropy rate of laser chaos and shot noise

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arXiv 2019年

作者： Guo, Xiaomin Liu, Tong Wang, Lijing Fang, Xin Zhao, Tong Virte, Martin Guo, Yanqiang Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan030024 China Vrije Universiteit Brussel Pleinlaan 2 Brussels1050 Belgium State Key Laboratory of Quantum Optics and Quantum Optics Devices Shanxi University Taiyuan030006 China

Evaluating entropy rate of high-dimensional chaos and shot noise from analog raw signals remains elusive and important in information security. We experimentally present an accurate assessment of entropy rate for physical process randomness. The entropy generation of optical-feedback laser chaos and physical randomness limit from shot noise are quantified and unambiguously discriminated using the growth rate of average permutation entropy value in memory time. The permutation entropy difference of filtered laser chaos with varying embedding delay time is investigated experimentally and theoretically. High resolution maps of the entropy difference is observed over the range of the injection-feedback parameter space. We also clarify an inverse relationship between the entropy rate and time delay signature of laser chaos over a wide range of parameters. Compared to the original chaos, the time delay signature is suppressed up to 95% with the minimum of 0.015 via frequency-band extractor, and the experiment agrees well with the theory. Our system provides a commendable entropy evaluation and source for physical random number generation. Copyright © 2019, The Authors. All rights reserved.

关键词： Entropy