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 search
2021-03-01 17:05:46 836KB 论文
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A passively Q-switched side-pumped laser with folded resonator is specially constructed for singlelongitudinal-mode smooth pulse output. Nd:YAG is chosen as the laser active medium and Cr<sup>4+</sup>:YAG as the saturable absorber medium. Additionally, the method of frequency selection by grating with 1200 line/mm and Fabry-Perot (F-P) etalon is used in the twisted-mode cavity. The single-frequency smooth pulses are produced with 10-Hz repetition rate, 20-ns pulse width, and 1.064-\m
2021-02-26 11:04:31 866KB 折叠腔 单纵模 光栅和F-P 被动调Q
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We report an all-fiber high power, single frequency large-mode area (LMA) linearly polarized ytterbiumdoped fiber amplifiers (YDFA) module, which is based on the master oscillator multi-stage power amplifiers (MOPA). The maximum output power is 43.8 W at a wavelength of 1064 nm when 60-W launched pump light is coupled, with high slope efficiency of 88%, polarization extinction rate (PER) >17.2 dB and nearly diffraction-limited beam quality (M2<1.1).
2021-02-26 09:05:48 961KB 单频 主震荡功 线偏振光 消光比
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A scheme for the photonic generation of frequency-tunable millimeter wave and terahertz wave signals based on a highly flat optical frequency comb is proposed and demonstrated experimentally. The frequency comb is generated using two cascaded phase modulators (PMs) and an electro-absorption modulato
2021-02-25 14:09:05 1.12MB 论文
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In this Letter, we focus on the theoretical analysis of the relativistic energy and angular distributions of the ejected photoelectrons during the relativistic tunnel ionization of atoms by intense, circularly polarized light. We make a small modification of the general analytical expressions for these distributions. The role of the initial momentum, the ponderomotive potential, and the Stark shift are considered. We also present the maximal angle of electron emission.
2021-02-23 18:04:14 303KB 论文
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针对UMA-RFID协议的安全漏洞,提出一个改进的超轻量级的RFID认证协议。通过修改UMA-RFID协议的交互方式,避免泄露标签标识符,保证读写器应答消息的新鲜性。该协议仅使用异或操作和移位操作,降低了对标签计算能力和存储能力的要求。分析结果表明,该协议可有效抵抗假冒攻击和重传攻击,适合于较低成本的RFID系统。
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In visible light communication, orthogonal frequency division multiplexing (OFDM) is an effective approach to improve the system speed. However, the nonlinearity of the light-emitting diode (LED) suppresses the transmission performance. The low-frequency part of the transmitted signal from LED suffe
2021-02-07 20:05:21 823KB
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A novel approach for generating flat optical frequency comb based on externally injected gain-switching distributed feedback semiconductor laser
2021-02-07 16:03:29 640KB 研究论文
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Compact Miniaturized-Element Frequency Selective Surface
2021-02-07 12:06:40 276KB 研究论文
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TTY :: ProgressBar 灵活而可扩展的进度条,适用于终端应用程序。 TTY :: ProgressBar为工具箱提供独立的进度条组件。 产品特点 可定制从许多选项中进行选择,以获取所需的行为。 灵活。 描述条形并从许多预定义的和。 可扩展。 定义以适应您的需求。 强大。 并行显示进度条。 显示进度的无限制操作。 随时并进度。 在进度栏中包含字符。 在所有ECMA-48兼容终端上均可使用。 安装 将此行添加到您的应用程序的Gemfile中: gem "tty-progressbar" 然后执行: $ bundle 或自己安装为: $ gem install
2021-02-06 19:07:32 90KB frequency rubygem terminal console-tool
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