高功率激光系统中全息“热像”效应

对高功率激光系统中存在的一种类似于小尺度自聚焦的非线性过程“热像”效应进行了理论分析和模拟计算。当一束经过遮光物调制的激光光束通过非线性介质后,在随后的光路上将产生一个亮点,即“热像”。“热像”处的光强比背景光强大几倍,因此位于“热像”附近位置的光学元件很可能遭受损伤。从全息成像的角度对“热像”的形成过程进行了分析。结果表明：“热像”的位置处于以非线性介质为中心与遮光物大约对称的地方,“热像”的光强是原始光强的(1+B)2倍。计算机模拟与理论计算结果吻合较好,验证了上述结果。     

多程放大腔镜准直研究

针对高功率激光装置对多程放大器腔镜准直的要求,利用小孔的像传递和光路自动准直的原理,设计出一套创新的腔镜准直调整方法,并且在SG-Ⅲ原型装置4程放大模拟实验平台上进行了实验验证。实验结果表明：自动准直系统能够在15min之内顺利完成主放大级系统的光路调整,光束近场调整精度值小于近场光斑直径的0.5%,光束远场调整精度小于0.3"。     

数字图象处理技术在碎片杀伤战斗部试验诊断中的应用

本文提出的数字图象处理技术,可用于测量爆炸金属碎片的质量和碎片质心的空间位置。它采用的原始图象由闪光X光照相获得。初步实验结果表明,这项技术是可行的。     

像增强器的光生背景噪声对微光目标质心探测精度的影响及其抑制方法

像增强器作为微光探测器件,在天文目标观测、空间目标捕获、跟踪和瞄准以及生物荧光光谱探测等方面发挥越来越大的作用。重点讨论了在微弱亮度的空间点目标探测应用中,像增强器的光生背景噪声对目标质心探测的影响。实验和分析表明,像增强器的光生背景噪声是由目标信号寄生而来的,并且呈现散粒噪声特性,无法采取屏蔽环境背景杂光、阈值去背景等方法来消除光生背景噪声,对目标信号质心探测的影响很大。提出一种减小这种影响的质心计算方法,实验证明是有效的。     

基于回波信号仿真的瑞利-喇曼-米激光雷达研制

在分析瑞利、喇曼和米散射仿真回波信号的基础上,研制了一台探测大气温度、气溶胶和卷云的瑞利-喇曼-米散射激光雷达,实现了一台激光雷达针对大气温度、气溶胶和卷云光学特性的多参数探测。为提高瑞利和喇曼微弱回波信号信噪比,采用了极高灵敏度的R4632光电倍增管和光子计数技术;为实现对大气气溶胶和卷云的探测,532 nm回波信号采取高低分层技术、高层通道回波衰减方法和探测器门控技术。瑞利-喇曼-米散射激光雷达的探测结果证明了利用仿真回波信号指导激光雷达设计的可行性。     

基于约束共轭梯度的高能闪光照相图像复原算法

针对闪光照相系统模糊较大、成像信噪比低的特点,提出了一种基于约束共轭梯度的闪光照相图像复原算法,将闪光照相图像复原问题转化为一个约束优化问题,引入基于非负、中值滤波和偏微分方程的光滑约束条件,并利用约束共轭梯度法迭代求最优解。数值试验表明,该算法能较好再现图像边缘信息,复原出的图像在信噪比和视觉方面都有较大提高。     

一种条纹变像管静态电子光学聚焦特性数值模拟

对ICF实验中条纹相机的重要组件变像管的工作过程进行了介绍,建立了其内部电子光学系统模型,对其静态电子光学特性进行了数值模拟。模拟软件采用ANSYS,数值计算基于有限元数值计算方法,并利用哈密顿原理求解泛函,在控制计算精度的基础上,得出了该电子光学系统的内部静电场分布和轴上电位分布,同时对静态条件下的电子轨迹进行了模拟计算。结果显示了与理论解析结果很好的相似性,同时初步探索了电极尺寸及电压参数对成像的影响。结果表明,电压参数的改变对光电子成像的影响要更大一些。     

A Hybrid Quantum Image-Matching Algorithm

Image matching is an important research topic in computer vision and image processing. However, existing quantum algorithms mainly focus on accurate matching between template pixels, and are not robust to changes in image location and scale. In addition, the similarity calculation of the matching process is a fundamentally important issue. Therefore, this paper proposes a hybrid quantum algorithm, which uses the robustness of SIFT (scale-invariant feature transform) to extract image features, and combines the advantages of quantum exponential storage and parallel computing to represent data and calculate feature similarity. Finally, the quantum amplitude estimation is used to extract the measurement results and realize the quadratic acceleration of calculation. The experimental results show that the matching effect of this algorithm is better than the existing classical architecture. Our hybrid algorithm broadens the application scope and field of quantum computing in image processing.     

Quantum Spatial Search with Electric Potential: Long-Time Dynamics and Robustness to Noise

We present various results on the scheme introduced in a previous work, which is a quantum spatial-search algorithm on a two-dimensional (2D) square spatial grid, realized with a 2D Dirac discrete-time quantum walk (DQW) coupled to a Coulomb electric field centered on the the node to be found. In such a walk, the electric term acts as the oracle of the algorithm, and the free walk (i.e., without electric term) acts as the “diffusion” part, as it is called in Grover’s algorithm. The results are the following. First, we run long time simulations of this electric Dirac DQW, and observe that there is a second localization peak around the node marked by the oracle, reached in a time O(N), where N is the number of nodes of the 2D grid, with a localization probability scaling as O(1/lnN). This matches the state-of-the-art 2D-DQW search algorithms before amplitude amplification We then study the effect of adding noise on the Coulomb potential, and observe that the walk, especially the second localization peak, is highly robust to spatial noise, more modestly robust to spatiotemporal noise, and that the first localization peak is even highly robust to spatiotemporal noise.     

湍流廓线激光雷达中的电光开关设计

利用晶体的电光效应设计了一种可以取代像增强器曝光闸门作用的电光开关系统,阐明了晶体电光效应的原理及电光开关取代像增强器的必要性与可行性,借助光学软件Zemax仿真得到了光开关的光路系统以及开关通断时的光斑图样,此仿真结果以及静态实验结果都表明,晶体光开关可应用于激光雷达光路中,且曝光时间可达ns量级,从而摆脱对像增强器的依赖。