1 中国科学院上海光学精密机械研究所高功率激光物理联合实验室， 上海 201800
2 中国科学院大学， 北京 100049
3 中国工程物理研究院上海激光等离子体研究所， 上海 201800
为适应高功率激光系统的紧凑空间需求，将基于二阶鬼像的远近光场耦合方案应用于高功率激光准直技术中，设计并搭建出灵敏的小型准直光学系统。提出完备的测试方案，验证了该方案的可行性，获得近场测量灵敏度为7.04 μm/pixel，远场测量灵敏度为18.14 (″)/pixel，并得到远场变化对近场的影响关系，用以优化光束校准。相比于传统远、近场分离的准直系统，该方案在满足成像质量和分辨率要求的同时，大幅缩减了光路和器件数量，远、近光场相互影响和校准的反馈处理更便捷。
激光光学 光场耦合 透镜系统设计 高功率激光 精密准直 鬼反射成像
Author Affiliations
Abstract
1 National Laboratory on High Power Laser and Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Shanghai Institute of Laser Plasma, Shanghai 201800, China
In high power laser facility for inertial confinement fusion research, final optics assembly (FOA) plays a critical role in the frequency conversion, beam focusing, color separation, beam sampling and debris shielding. The design and performance of FOA in SG-II Upgrade laser facility are mainly introduced here. Due to the limited space and short focal length, a coaxial aspheric wedged focus lens is designed and applied in the FOA configuration. Then the ghost image analysis, the focus characteristic analysis, the B integral control design and the optomechanical design are carried out in the FOA design phase. In order to ensure the FOA performance, two key technologies are developed including measurement and adjustment technique of the wedged focus lens and the stray light management technique based on ground glass. Experimental results show that the design specifications including laser fluence, frequency conversion efficiency and perforation efficiency of the focus spot have been achieved, which meet the requirements of physical experiments well.
final optics assembly high power laser facility inertial confinement fusion. High Power Laser Science and Engineering
2018, 6(2): 02000e14
Author Affiliations
Abstract
1 National Laboratory on High Power Laser and Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Key Laboratory of High Power Laser and Physics, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
3 Shanghai Institute of Laser Plasma, China Academy of Engineering Physics, Shanghai 201800, China
The Shen-Guang II Upgrade (SG-II-U) laser facility consists of eight high-power nanosecond laser beams and one short-pulse picosecond petawatt laser. It is designed for the study of inertial confinement fusion (ICF), especially for conducting fast ignition (FI) research in China and other basic science experiments. To perform FI successfully with hohlraum targets containing a golden cone, the long-pulse beam and cylindrical hohlraum as well as the short-pulse beam and cone target alignment must satisfy tight specifications (30 and $20~\unicode[STIX]{x03BC}\text{m}$ rms for each case). To explore new ICF ignition targets with six laser entrance holes (LEHs), a rotation sensor was adapted to meet the requirements of a three-dimensional target and correct beam alignment. In this paper, the strategy for aligning the nanosecond beam based on target alignment sensor (TAS) is introduced and improved to meet requirements of the picosecond lasers and the new six LEHs hohlraum targets in the SG-II-U facility. The expected performance of the alignment system is presented, and the alignment error is also discussed.
laser drivers petawatt lasers spherical hohlraum target alignment target area High Power Laser Science and Engineering
2018, 6(1): 01000e10
华中科技大学电子科学与技术系, 湖北 武汉 430074
本文推导了细胞膜电容与血糖浓度之间的关系, 并将这种关系应用到Pauly和Schwan提出的弛豫模型中, 再将弛豫模型应用于多重Cole-Cole介电模型, 最后通过介电模型得出阻抗模型, 建立起人体血糖浓度与组织介电谱, 阻抗谱之间的联系。通过分析发现, 细胞膜电容随着血糖浓度增加而增大, 且当血糖浓度趋于无穷大时, 细胞膜电容等于血糖浓度为0时细胞膜电容的1.53倍。对介电谱的仿真得出, 当外加信号频率小于1 MHz时, 介电常数实部随着葡萄糖浓度改变而发生明显变化。阻抗谱的研究结果表明, 随着葡萄糖浓度的升高, 阻抗的实部减小, 阻抗虚部模增大, 且分别在频率为1.48 MHz和0.55 MHz时变化得最快。本文建立的模型为血糖无创检测提供了一种新的方法和手段。
葡萄糖 细胞膜电容 介电常数 阻抗 glucose membrane capacitance dielectric constant impedance
Author Affiliations
Abstract
1 中国科学院上海光学精密机械研究所高功率激光物理联合实验室, 上海 201800
2 中国工程物理研究院上海激光等离子体研究所, 上海 201800
The wedge-shaped lens is the key and special optical component of the final optics assembly (FOA) in high power laser facility. The wedge-shaped lens wedge angle measurement plays a remarkable role in focusing performance of high power laser. If processing angle and work attitude of the wedge-shaped lens deviate from the specific work angle, big surface deviation will be introduced into the FOA. Special shape of the wedge-shaped lens is not conducive to the measurements of the transmission profile and wedge angle. A set of wedge-shaped lens measurement adjustment programmes is proposed, including measurement of the wedge-shaped lens in processing process, and off-line measurement of wedge-shaped lens during alignment and on-line measurement during the debugging process. The scheme can ensure the processing precision and working attitude of the wedge-shaped lens, guarantee the beam quality and the positioning accuracy of the FOA components of high power laser system.
光学器件 高功率激光装置 终端光学组件 楔形透镜 楔角误差 塔差 optical devices high power laser facility final optics assembly wedge-shaped lens wedge angle error tower error Collection Of theses on high power laser and plasma physics
2015, 13(1): 0408006
1 中国科学院上海光学精密机械研究所高功率激光物理联合实验室, 上海 201800
2 中国工程物理研究院上海激光等离子体研究所, 上海 201800
楔形透镜是高功率激光系统终端光学组件的关键元件，也是较为特殊的光学元件，楔形透镜的楔角测量关系着高功率激光的聚焦性能。终端组件中楔形透镜的加工角度、工作姿态一旦偏离了特定的工作角度，终端组件会引入大的面形偏差，楔形透镜特殊的形状不利于楔形透镜面形、楔角的测量。提出了一整套楔形透镜测量调整方案，包括楔形透镜加工过程中的测量方案，楔形透镜安装过程中的离线测量与调整方案，以及终端组件上线调试过程中的在线调试测量方案。该套方案的实施能够保证楔形透镜的加工精度，及组件中楔形透镜能够工作在最佳工作姿态，保障了高功率激光系统终端组件的光束质量和定位精度。
光学器件 高功率激光装置 终端光学组件 楔形透镜 楔角误差 塔差
1 中国科学院 上海光学精密机械研究所, 高功率激光物理联合实验室, 上海 201800
2 中国科学院大学, 北京 100049
为了提高熔石英元件表面抗激光损伤阈值, 利用超声波辅助HF酸研究平滑光学元件表面缺陷形貌和去除刻蚀后残留物效果, 通过扫描电子显微镜电镜和原子力显微镜记录表面形貌结构, 以及单脉冲激光辐照测试抗损伤阈值确定实验参数。研究表明, 超声波场的引入能催化HF酸的刻蚀速率、提高钝化效果并且更易剥离嵌入的亚μm级杂质粒子。经过实验测试, 获得了熔石英类元件相匹配的超声辅助HF酸刻蚀实验参数, 研究结果对应用超声波辅助HF酸研究熔石英表面抗激光损伤有重要意义。
激光光学 熔石英 超声波 损伤阈值 化学刻蚀 laser optics fused silica ultrasonic damage threshold chemical etching 强激光与粒子束
2015, 27(1): 012001
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Science, Shanghai 201800, China
2 Graduate University of Chinese Academy of Science, Beijing 100049, China
Laser-induced damage (LID) to optical glass has become a growing problem in high-power laser systems. It is well known that the main reason of glass being damaged is due to defects and impurities in the material. Damage caused by subsurface defects (SSDs) is especially common in actual system running. Accordingly, in the presence of SSDs, a simple and alternative calculation method is developed to evaluate the enhancement of light field around the incident and exit surface. This ray tracing approach, based on the classical optics theory, is very direct and clear to show the optical phenomena of light intensity enhancement. Some basic SSD shapes have been studied and investigated here, which reveals the importance and boundary condition of controlling the size and density of SSDs in grinding and polishing process. Finally, to achieve optimal breadth depth ratio, the least etching amounts by hydrofluoric (HF) acid is investigated. The theoretical analysis and simulation results provide an appropriate range of removal amounts, which is very important in the HF etching process.
ray tracing subsurface defect total internal reflection interference subsurface damage Collection Of theses on high power laser and plasma physics
2014, 12(1): 926609
Author Affiliations
Abstract
1 中国科学院上海光学精密机械研究所高功率激光物理联合实验室, 上海 201800
2 上海大学机电工程与自动化学院, 上海 200072
High accuracy of target aiming and positioning is required in the study of the inertial confinement fusion (ICF). A system based on the chamber center reference system, the target positing system and the target alignment sensor is designed. The finite element method is used for analyzing the static deformation and transient stability of this system, and it proposes a calibration method of the high resolution parallel light pipe to achieve the system coupling precision. It achieves target aiming and positioning precision better than 12 μm of the SG-II updated laser facility. Through the SG-II updated laser facility single laser beam across the Φ 800 μm hole target, the perforation efficiency is 97.5%. This provides a solid foundation for high accuracy targeting of the follow-up physical experiment′s requirement.
激光器 高功率激光 瞄准 靶定位 有限元分析 精密校准 lasers high power laser aiming target positioning finite element analysis precision calibration Collection Of theses on high power laser and plasma physics
2014, 12(1): 1208002
1 中国科学院上海光学精密机械研究所，上海 201800
2 中国工程物理研究院上海激光等离子体研究所，上海 201800
真空环境下大口径光学元件的装夹采用传统有机物无应力装夹方式会带来有机污染等各种问题。设计了一种大口径平面光学元件的夹具和装夹方案，利用金属结构直接装夹大口径平面光学元件，可在降低金属装夹框表面加工精度和光学元件处于任意倾斜角度等情况下，不产生光学元件装夹应力，同时避免了传统有机物无应力装夹而带来的有机污染。可广泛应用于大口径平面光学元件在光学工程、光学实验装置中的装夹。
光学器件 无应力装夹 全金属装夹 弹性支点 大口径光学元件 有机污染 激光与光电子学进展
2014, 51(11): 112302
