Author Affiliations
Abstract
1 School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China
2 Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou 510632, China
This paper firstly, to the best of our knowledge, proposed two-dimensional (2D) encryption based on the Arnold transformation for implementing a secure DC-biased optical orthogonal time-frequency multiplexing (DCO-OTFM) in optical-wireless communications (OWCs). The encrypted data is transformed to the particular 2D matrix and decrypted by the only key to get the correct information. Meanwhile, the number of keys in 2D encryption is enormous, which prevents eavesdroppers from exhaustively searching secret keys rapidly to find the right decryption. Numerical results demonstrate that the secure DCO-OTFM based on 2D encryption can effectively prevent signal decryption from the eavesdropper, which has good secure performance for applying in OWC.
orthogonal time-frequency multiplexing two-dimensional encryption physical layer security optical-wireless communications Chinese Optics Letters
2021, 19(5): 050603
1 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China
2 School of Materials Science and Engineering, Wuhan University of Technology, Wuhan 430070, China
3 School of Aerospace, Transport and Manufacturing, Cranfield University, Cranfield, Bedfordshire, MK43 0AL, UK
4 Department of Materials Science and Engineering, Monash University, VIC 3800, Australia
Frontiers of Optoelectronics
2020, 13(3): 272
1 中国科学院合肥物质科学研究院,技术生物与农业工程研究所,合肥 230031
2 中国科学技术大学,合肥 230026
多氯联苯是一种持久性有机污染物,它在环境中极难分解,并通过食物链可在生物体内富集,从而对生态系统和人类健康造成严重危害。目前,多氯联苯在土壤、垃圾处理厂、天然水域及水生生物体内仍广泛存在,所以,亟需建立一种快速、灵敏、抗干扰的痕量检测方法。本项工作以金包裹二氧化硅的球形纳米颗粒(SiO2@Au)为探针,采用表面增强拉曼光谱(Surface-Enhanced Raman Spectroscopy,SERS)技术对多氯联苯进行痕量检测。研究中,我们制备了不同大小、形状均一的金包裹二氧化硅球形纳米粒子(SiO2@Au)(粒径范围为200~310 nm),并将制备好的纳米粒子用于溶液中PCB-77的检测。结果发现,在红外激光激发下,所制备的SiO2@Au纳米粒子对PCB-77分子都显示了较好的SERS检测效果,而用200 nm 的SiO2@Au纳米颗粒检测PCB-77,其检测低限可达10-7 M。这项工作为环境中的有机污染物痕量检测提供了一种有效可行的方法。
表面增强拉曼光谱 金包二氧化硅纳米颗粒 多氯联苯 surface-enhanced Raman spectroscopy gold-coated silica nanoparticles polychlorinated biphenyls(PCBs) PCB-77 PCB-77
1 State Key Laboratory of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology,Wuhan 430070,
2 Wuhan National Laboratory for Optoelectronics, Huazhong Univesity of Science and Technology, Wuhan 430074, China
Cu2ZnSn(S,Se)4 (CZTSSe) is considered as the promising absorbing layer materials for solar cells due to its earth-abundant constituents and excellent semiconductor properties. Through solution-processing, such as various printing methods, the fabrication of high performance CZTSSe solar cell could be applied to mass production with extremely low manufacturing cost and high yield speed. To better fulfill this goal, environmental-friendly inks/solutions are optimum for further reducing the capital investment on instrument, personnel and environmental safety. In this review, we summarized the recent development of CZTSSe thin films solar cells fabricated with benign solvents, such as water and ethanol. The disperse system can be classified to the true solution (consisting of molecules) and the colloidal suspension (consisting of nanoparticles).Three strategies for stabilization (i.e., physical method, chemical capping and self-stabilization) are proposed to prepare homogeneous and stable colloidal nanoinks. The one-pot self-stabilization method stands as an optimum route for preparing benign inks for its low impurity involvement and simple procedure. As-prepared CZTSSe inks would be deposited onto substrates to form thin films through spin-coating, spraying, electrodeposition or successive ionic layer adsorption and reaction (SILAR) method, followed by annealing in a chalcogen (S- or Se-containing) atmosphere to fabricate absorber. The efficiency of CZTSSe solar cell fabricated with benign solvents can also be enhanced by constituent adjustments, doping, surface treatments and blocking layers modifications, etc., and the deeper research will promise it a comparable performance to the non-benign CZTSSe systems.
Cu2ZnSn(S Cu2ZnSn(S Se)4 (CZTSSe) Se)4 (CZTSSe) solar cell solar cell benign solvents benign solvents metal chalcogenide complexes metal chalcogenide complexes (MCCs) solution processing Frontiers of Optoelectronics
2015, 8(3): 252
1 School of Science, Changchun University of Science and Technology, Changchun 130022, China
2 Wuhan National Laboratory for Optoelectronics (WNLO), Huazhong University of Science and Technology, Wuhan 430074, China
3 Department of Environmental Science, College of Environmental Sciences, Minzu University of China, Beijing 100081, China
4 School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China
Frontiers of Optoelectronics
2014, 7(1): 37
中国工程物理研究院 流体物理研究所, 四川 绵阳 621999
果冻内爆实验是一种研究柱形汇聚条件下Rayleigh-Taylor不稳定性的实验方法，由于高速摄影图像不能分辨反弹阶段果冻内界面的扰动，因此采用中低能X光照相CCD相机接收技术开展果冻与气体混合区域的实验研究，获得了果冻环在不同时刻压缩、反弹的发展状况及其内外边界，并观测到果冻质量分数降低时果冻与气体混合界面的变化。实验结果表明：X光照相可作为测量湍流混合区域的半定量测试技术，有助于研究果冻内爆中的气液界面Rayleigh-Taylor不稳定性现象。
X光照相 果冻内爆实验技术 Rayleigh-Taylor不稳定性 湍流混合区域 X-ray radiography gelatin implosion technique Rayleigh-Taylor instability turbulent mixing zone 强激光与粒子束
2014, 26(3): 034002
1 中国工程物理研究院 流体物理研究所, 绵阳 621900
2 中国工程物理研究院 流体物理研究所 冲击波物理与爆轰物理国防科技重点实验室, 绵阳 621900
为了研究短脉冲强激光辐照下同轴数字全息图像中的杂散光斑, 进行了短脉冲强激光辐照和停止激光辐照情况下CCD图像采集的实验, 采用粒子衍射原理和CCD输出电信号的过程分析了CCD图像灰度的变化, 得到了像素上灰尘的衍射及CCD吸收激光能量导致复位电平失常是杂散光斑及阴影产生的原因, 受热效应和记忆效应的影响, 激光辐照停止后CCD图像采集失常。结果表明, 激光辐照停止后随着热量的消散, 杂散光斑逐渐消失, 去除灰尘并延长CCD的图像采集时间间隔, 避免CCD产生热积累能有效消除杂散光斑。
光电子学 杂散光斑 过饱和效应 面阵CCD 热效应 激光能量 optoelectronics stray facula supersaturation effect array CCD thermal effect laser energy
1 中国工程物理研究院 激光聚变研究中心， 四川 绵阳 621900
2 中国工程物理研究院 流体物理研究所， 四川 绵阳 621900
为探索研究飞秒激光在材料中驱动冲击波的相关特性，采用激光脉冲频域干涉测试技术对脉冲宽度35 fs、脉冲能量0.7 mJ、功率密度1014 W/cm2量级的飞秒激光脉冲在200 nm厚铝膜中驱动冲击波的过程进行了实验测量。通过测量冲击波在铝膜中的渡越时间，获得激光脉冲在铝材料中驱动的冲击波平均速度约为6 km/s；通过对不同时刻铝膜自由面频域干涉场测量结果的分析，获得铝材料自由表面速度达1 km/s，根据平面冲击波的关系，推算其冲击压强达到9 GPa。
飞秒激光 冲击波 频域干涉 铝膜 femtosecond laser shock wave frequency-domain interferometry aluminum film
中国工程物理研究院 流体物理研究所冲击波物理与爆轰物理实验室, 四川 绵阳 621900
介绍了一种具有fs时间分辨力的超短脉冲激光频域干涉测试技术, 详细论述了该技术的工作原理和系统构成, 指出传输时间差和相位差是影响频域干涉条纹周期的主要因素。采用脉冲激光频域干涉仪测量了200 nm厚度铝膜在波长800 nm、单脉冲能量0.7 mJ、脉宽35 fs脉冲激光作用下的运动速度剖面。在单次飞秒脉冲激光作用下, 铝膜自由面的运动速度峰值可达960 m/s, 速度剖面的上升前沿小于5.77 ps,表明脉冲激光频域干涉技术可用于测量材料在超快脉冲激光作用下的冲击动力学参数。
飞秒激光 频域干涉 相位剖面 速度剖面 femtosecond pulse frequency-domain interferometry phase profile velocity profile
中国工程物理研究院流体物理研究所 冲击波物理与爆轰物理实验室,四川 绵阳 621900
通过对频域干涉原理的深入研究,本文提出了一种超快时间分辨力的脉冲激光频域干涉技术。采用该技术方法可精确同步泵浦－探测实验中泵浦脉冲和探测脉冲的传输时间,其同步精度与脉冲激光器脉宽相当。本文详细论述了频域干涉技术的系统构成和工作原理,数值模拟了飞秒脉冲激光频域干涉仪的输出信号,指出当频域干涉仪输出的条纹数最少时,两脉冲之间的传输时间差即达到最小,最后通过动态实验验证了理论推导结果。
飞秒脉冲激光 频域干涉 时间分辨力 泵浦探测实验 femtosecond pulse frequency-domain interferometry time resolution pump-probe experiment
