中国电子科技集团公司第五十八研究所，江苏 无锡 214035
红外热成像系统采集的数据大都是高动态范围，为了实现高动态红外图像的可视化，动态范围压缩和细节增强技术的研究至关重要。针对传统方法存在的梯度反转伪影、低对比度细节丢失、背景噪声过增强等问题，提出一种基于边窗滤波的高动态红外图像压缩增强方法。首先，采用边窗滤波将原始红外图像分解为基础分量和细节分量；然后，根据基础分量的灰度级分布情况，设计一种自适应阈值的平台直方图算法，对基础分量进行压缩；接着，利用双边滤波器核权重分布特点，生成自适应增益系数，对细节分量进行增强；最后，对基础分量和细节分量进行加权融合，并将结果量化到8位动态范围。实验结果表明，与经典的压缩增强方法相比，所提方法对强边缘具有更好的保边效果，可以有效避免梯度反转伪影和光晕问题，细节信息更丰富，背景噪声抑制效果更好，对不同场景的适应性更强。
红外成像 边窗滤波 动态范围压缩 细节增强 自适应增益 激光与光电子学进展
2023, 60(24): 2410009
Author Affiliations
Abstract
1 National Laboratory of Solid Microstructures and School of Physics, Nanjing University, Nanjing 210093, China
2 Department of Applied Mathematics and Physics, Anhui Polytechnic University, Wuhu 241000, China
3 Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, China
4 Collaborative Innovation Center of Solid-State Lighting and Energy-Saving Electronics, Nanjing University, Nanjing 210093, China
Structured optical fields embedded with polarization singularities (PSs) have attracted extensive attention due to their capability to retain topological invariance during propagation. Many advances in PS research have been made over the past 20 years in the areas of mathematical description, generation and detection technologies, propagation dynamics, and applications. However, one of the most crucial and difficult tasks continues to be manipulating PSs with multiple degrees of freedom, especially in three-dimensional (3D) tailored optical fields. We propose and demonstrate the longitudinal PS lines obtained by superimposing Bessel-like modes with orthogonal polarization states on composite vector optical fields (VOFs). The embedded PSs in the fields can be manipulated to propagate robustly along arbitrary trajectories, or to annihilate, revive, and transform each other at on-demand positions in 3D space, allowing complex PS’ topological morphology and intensity patterns to be flexibly customized. Our findings could spur further research into singular optics and help with applications such as micromanipulation, microstructure fabrication, and optical encryption.
Photonics Research
2023, 11(1): 121
近视是一种常见眼病, 在我国儿童青少年群体中发病率高, 并逐渐呈低龄化趋势。中高度近视会造成多种严重眼科并发症, 高度近视或将成为全球首要致盲病因。基于周边离焦学说论述渐进多焦眼镜、周边离焦框架眼镜、多点正向离焦近视眼镜、软性角膜接触镜和角膜塑形镜等光学矫正手段对儿童青少年近视防控研究的进展, 探讨减缓眼轴生长的技术手段, 为儿童青少年近视预防和控制工作提供更多临床指导。
近视 视网膜周边离焦 光学矫正 myopia peripheral defocus of the retina optical correction
Author Affiliations
Abstract
National Laboratory of Solid Microstructure and School of Physics, Nanjing University, Nanjing 210093, China
We develop a method for completely shaping optical vector beams with controllable amplitude, phase, and polarization gradients along three-dimensional freestyle trajectories. We design theoretically and demonstrate experimentally curvilinear Poincaré vector beams that exhibit high intensity gradients and accurate state of polarization prescribed along the beam trajectory.
laser beam shaping polarization diffraction Chinese Optics Letters
2021, 19(3): 032602
强激光与粒子束
2020, 32(11): 112004
高分三号卫星是世界上成像模式最多的合成孔径雷达(SAR)卫星,高分三号SAR图像与多光谱图像融合可以改善图像视觉效果。因此提出一种新的研究思路,即利用非下采样轮廓波变换(NSCT)模拟出既包含多光谱谱段信息又体现SAR图像细节信息的高分辨率图像,则融合可不拘泥于具体算法。同时提出两种基于NSCT的高分辨率图像模拟方法,利用高分三号3 m、5 m分辨率SAR图像和高分一号16 m分辨率图像进行实验,采用不同融合算法验证了该思路的有效性。研究结果表明:传统的SAR和多光谱图像直接融合的方法能够保持SAR的细节信息,但噪声明显,且光谱信息损失大;而所提出的NSCT平均图像和平均NSCT图像可以保留融合结果的光谱信息,且模拟的光谱信息前者比后者更贴近多光谱。
图像处理 合成孔径雷达与可见光图像 非下采样轮廓波变换 高分三号卫星 评价指标 光学学报
2018, 38(11): 1110002
1 中国工程物理研究院激光聚变研究中心, 四川 绵阳 621900
2 中国科学院西安光学精密机械研究所, 陕西 西安 710119
为充分利用亚皮秒紫外激光器的大能量、超短脉宽的紫外激光输出特性, 配套建立了激光惯性约束聚变(ICF)诊断设备性能指标的标定平台。标定平台具备激光能量测量、光传输延迟、光束分割与等比递减、序列光脉冲产生器等功能, 可为相关诊断设备提供结构支撑和高真空度的运行环境。通过机械与光学设计完成了平台各部件的研制, 并利用该平台对X射线二极管的响应时间、X光条纹相机的扫速、X射线分幅相机的动态范围等指标进行了标定。结果表明, 该标定平台与亚皮秒紫外标定源的匹配度良好, 可实现多种诊断设备性能指标的精密标定。
激光器 亚皮秒紫外激光器 标定平台 诊断设备 动态范围 扫描速度
Author Affiliations
Abstract
1 Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
2 Research Center of Laser Fusion, Chinese Academy of Engineering Physics, Mianyang 621900, China
3 Center for Applied Physics and Technology, Peking University, Beijing 100871, China
4 Collaborative Innovation Center of IFSA, Shanghai Jiao Tong University, Shanghai 200240, China
5 China Academy of Engineering Physics, Mianyang 621900, China
The octahedral spherical hohlraums have natural superiority in maintaining high radiation symmetry during the entire capsule implosion process in indirect drive inertial confinement fusion. While, in contrast to the cylindrical hohlraums, the narrow space between the laser beams and the spherical hohlraum wall is usually commented. In this Letter, we address this crucial issue and report our experimental work conducted on the SGIII-prototype laser facility which unambiguously demonstrates that a simple design of cylindrical laser entrance hole (LEH) can dramatically improve the laser propagation inside the spherical hohlraums. In addition, the laser beam deflection in the hohlraum is observed for the first time in the experiments. Our 2-dimensional simulation results also verify qualitatively the advantages of the spherical hohlraums with cylindrical LEHs. Our results imply the prospect of adopting the cylindrical LEHs in future spherical ignition hohlraum design.
Spherical hohlraum Laser propagation Cylindrical laser entrance hole Laser spot movement Matter and Radiation at Extremes
2016, 1(1): 2
Author Affiliations
Abstract
1 Institute of Applied Physics and Computational Mathematics, Beijing 100088, China
2 Research Center of Laser Fusion, Chinese Academy of Engineering Physics, Mianyang 621900, China
3 Center for Applied Physics and Technology, Peking University, Beijing 100871, China
4 Collaborative Innovation Center of IFSA, Shanghai Jiao Tong University, Shanghai 200240, China
5 China Academy of Engineering Physics, Mianyang 621900, China
Corrigendum Text: On page 2 of this letter, there is a misprint in the unit. The unit of the geometrical dimension of the spherical hohlraums on this page should always be “mm” rather than “mm”, i.e. in the second paragraph, “…with 800 J per beam at 0.35 mm…” should be “…with 800 J per beam at 0.35 μm…”, “The slit of 400 mm width is parallel…” should be “The slit of 400 μm width is parallel…”, “The laser focal diameter is about 500 mm…” should be “The laser focal diameter is about 500 μm…”; in the third paragraph, “…we take 850 μm as the radius…” should be “…we take 850 mm as the radius…”, “The LEH radius RL is 400 mm…” should be “The LEH radius RL is 400 μm…”, “…the radius of the cylindrical LEH outer ring is taken as 1.5 RL = 600 mm” should be “…the radius of the cylindrical LEH outer ring is taken as 1.5 RL = 600 μm”. This mistake does not affect any of the main results of the original letter.
Matter and Radiation at Extremes
2016, 1(2): 133
1 中国工程物理研究院激光聚变研究中心， 四川 绵阳 621900
2 中国科学院微电子研究所纳米加工与新器件集成技术实验室， 北京 100029
3 中国科学院高能物理研究所， 北京 100049
提出一种基于掠入射微柱面反射镜阵列的X射线成像型平响应低通滤波技术。根据X射线光学理论，介绍了基于微柱面反射镜阵列的平响应低通滤波原理，分析了元件透射谱的计算方法。基于电子束刻蚀技术在聚酰亚胺衬底上制作了金柱体直径200 nm、深度1.3 μm、占空比0.393的微柱面镜阵列样品，根据理论计算在2°掠射角时其截止能量为1250 eV，响应不平整度为5.7%。利用转角精度优于0.1°的三维精密转角机构，在北京同步辐射装置的4B7B软X射线束线站标定样品在不同掠入射角下的透射率，得到初步标定结果。标定结果显示，在1 keV以上的不同能点各曲线均有下降趋势，且角度越大下降能点越偏软，说明掠射角的增大对较高能的X射线具有明显抑制效果。由于电子束刻蚀的技术局限性，样品的深宽比、侧壁垂直度、侧壁粗糙度等参数并未达到理论要求，所以标定结果与理论计算值有一定差异。
X射线光学 平响应低通滤波 掠入射 微柱面镜阵列 同步辐射
