论文部分内容阅读
防偷拍的激光相机
【出 处】
：
激光与光电子学进展
【发表日期】
：
2006年43期
其他文献
An effective mode selection is important for the multi-core photonic crystal fiber (PCF) to obtain good output. Talbot cavity is popular to lock the in-phase mode, but few satisfactory experimental results have been reported. In this paper, a dual-Talbot
期刊
The contrast mechanism of different polarization imaging techniques for melanoma in mouse skin is studied using both experiments and Monte Carlo simulations. Total intensity, linear polarization difference imaging (DPI), degree of polarization imaging (DO
In vivo fiber photometry of neural activity in response to optogenetically manipulated inputs in fre
In vivo fiber photometry is a powerful technique to analyze the dynamics of population neurons during functional study of neuroscience. Here, we introduced a detailed protocol for fiber photometry-based calcium recording in freely moving mice, covering fr
Miniature Fabry-Perot interferometric sensor for temperature measurement based on photonic crystal f
A novel miniature Fabry-Perot interferometric (FPI) temperature sensor is proposed and demonstrated experimentally. The modal interferometer is fabricated by just splicing a section of photonic crystal fiber (PCF) with a single-mode fiber (SMF). The air h
期刊
设计了工作在X波段的相对论速调管放大器同轴双间隙输出结构，并采用3维PIC程序对其进行了粒子模拟，分析了输出微波功率随直流渡越角、输出腔品质因数值等相关参数的变化，对输出腔体结构进行了优化设计。模拟结果表明：同轴双间隙输出结构可以降低束流的势能，增加束流与腔体的作用时间，提高速调管的微波提取效率。模拟中采用束压600 kV、束流5 kA、调制深度100%和峰值频率9.37 GHz的电子束以及1T的轴向引导磁场强度，得到了周期平均功率1.2 GW、峰值频率9.37 GHz、效率40%的微波输出。
Intravenous cannulation is the most important phase in medical practices. Currently, limited literature is available about visibility of veins and the characteristics of patients associated with di±cult intravenous access. In modern medical treatment, a m
基于自相似光纤激光放大技术,通过非线性光谱展宽突破光纤增益带宽的限制,结合高效色散补偿以获得高功率超短脉冲放大输出,最终得到中心波长1030 nm、重复频率40 MHz、平均功率34 W、脉冲宽度50 fs的高质量脉冲输出,对应峰值功率17 MW。该系统采用可饱和吸收体锁模,采用啁啾光纤布拉格光栅补偿腔内色散,相对于啁啾脉冲放大技术具有结构简单、集成度高等优点。实验结合光纤热管理技术和数字测控技术(FPGA),显著提升了系统的稳定性和鲁棒性,极大推动了高功率飞秒光纤激光在下游诸多科学与技术领域的应用。
精确标定能够发挥出聚焦型光场相机在场景重建和非接触测量等方面的作用。而标定精度提升的关键之一在于精确的特征提取算法。为了提升特征检测的精度和效率,提出一种基于原始图的棋盘格角点检测算法。利用稳健的角点检测算子对原始图角点进行检测,并利用二维角点与三维光场圆域特征的对应关系进行角点筛选。然后,利用图像一致性对角点进行亚像素优化。进行了仿真角点检测实验和仿真标定实验,并基于R29聚焦型光场相机得到的重
利用“跳跃模型”讨论外加交变电场(包括正弦和方波电场)对光折变基频空间电荷场建立的影响, 给出了空间电荷场基频分量随时间、 外加交流电场振幅频率等变化的通解表达式。 发现基频空间电荷场虚部和实部的振荡频率分别是外加交流电场振荡频率的两倍和一倍。 当外加交变电场频率较大时光折变光栅是相移型的。 这和基于“带导模型”给出的数值结果相符。