直接积分法研究电子光学成像系统的时间像差理论

提出了计算动态电子光学成像系统时间像差系数的新方法——直接积分法.以阴极面逸出的轴向电子初能为ε_z1（0≤ε_z1≤ε_0max）的近轴电子 轨迹为比较 基准,给出了时间像差的定义,详细叙述了直接积分法并给出求解动态电子光学成像系统时 间像差系数的积分表达式.τ变分法求得的二级几何时间像差系数必须求解微分方程, 而直接积分法求得的二级几何时间像差系数全部以积分形式表示,仅需进行积分运算,更适 用于成像系统的实际计算与设计. 关键词： 电子光学成像系统 阴极透镜 动态电子光学 时间像差理论     

人眼大视场波前像差特性研究

应用改进的Hartmann-Shack波前传感器人眼像差仪,测量了5只5.2 mm瞳孔的正常眼,向鼻侧和颞侧两个水平方向50°视场角Zernike第二级到第十级的波前像差. 视场角从鼻侧和颞侧两个水平方向从0°增大到50°时,Zernike第三级波前像差的rms值平均增大2倍；Zernike第四级波前像差的rms值平均增大1.8倍；Zernike第五级到第十级波前像差的rms值平均增大1.7~1.3倍.     

Aberration-free two-thin-lens systems based on negative-index materials

Since the complete correction of all five monochromatic Seidel aberrations for a singlet lens with random shape or a two-thin-lens system is unprocurable merely by using the conventional positive-index materials both in theory and practice, this paper proposes that when one or both of the two lenses is/are made from negative-index materials, an imaging system composed of a pair of spherical thin lenses is possible to form a real image, in air, free from all five monochromatic Seidel aberrations. The calculated numerical solutions to the structural parameters of such lens systems possessing superior performance are provided and examples of them are illustrated for the given combinations of the two lenses＇ refractive indices, including an ultimately-remote imaging system.     

An optical system with aberrations on diffraction integrals written in terms of a generalized ABCD matrix

Abstract: In this paper, we consider the transformation of a ray beam as it passes through an optical system containing a glass plate with parallel surfaces inclined to the optical axis at the Brewster’s angle, by investigating the effects of the optical system on amplitude and phase distributions. By applying generalized matrix optics and diffraction integrals and considering the influence of a quarter of a wavelength of aberration on the transmitted amplitude and phase distributions at the focus of a de-collimating lens, we find that the central peak amplitude descends from 1.0 to 0.8 and the phase distortion is less than π/2. The general feature of the amplitude distribution shows an elongation along the y-axis perpendicular to the optical axis in the direction of tilt of the inclined plate, and conforms to the inclination direction of the glass plate.      

含衍射光学元件的薄透镜系统初级像差的PWC表示

为了形成与中国传统光学设计体系相街接的折衍混合光学设计的理论和方法,研究了PWC表示的折衍混合薄透镜系统初级像差理论,建立了赛德尔像差和数与P、W、C的函数关系,以及P-∞、W-∞、C-∞与衍射透镜结构的函数关系。采用PWC表示的初级像差理论和高折射率设计方法,获得了折衍混合消色差李斯特型中倍显微物镜的初始结构,结果表明其赛德尔像差和数的理论值与设计值相吻合,从而验证了折衍混合光学系统PWC表示的初级像差理论和高折射率设计方法。优化设计结果与传统李斯特型物镜相比较,具有更长的工作距,且像质显著提高,由于前组为单片塑料透镜,有利于批量生产。     

The study of the effects of higher-order aberrations on human contrast sensitivity with white-light retinal aerial image modulation (AIM)

The impact of higher-order aberrations on contrast sensitivity function (CSF) is calculated using individual white-light retinal aerial image modulation (AIM). Wavefront aberrations of 26 eyes are measured with Hartmann-Shack sensor, and the CSFs in natural light are acquired through a range of 2-48 c/deg. The white-light AIM is computed as the ratio of modulation transfer function (MTF) in white-light to CSF. Through manipulating the higher-order aberrations, the affected CSF is predicted by employing the white-light AIM. We find that coma aberration mainly influences CSF at higher spatial frequency and spherical aberration affects CSF in the whole spatial frequency range non-selectively. Additionally, it is spherical aberration rather than coma that impacts the CSF more substantially. Furthermore, the maximum value of area under CSF (AUCSF) is obtained without full correction of higher-order aberration, which indicates that there is compensatory mechanism among aberrations.     

两电极静电同心球系统的近轴电子光学及其空间-时间像差

将从近轴解出发研究两电极静电同心球系统的空-时轨迹及其像差.由近轴轨迹方程和近轴运动方程出发,先求解两电极静电同心球系统中自光阴极逸出的运动电子的近轴空间-时间轨迹,然后讨论此系统的静动态电子光学及其空间-时间像差,揭示近轴光学系统成像的一般规律.文中定义和推导了各级近轴空间像差和近轴时间像差,得到了与关于近轴空间-时间像差同样的结论,表明完全可以直接由近轴轨迹方程和近轴运动方程出发来研究理想成像及其空间-时间像差.     

Aspherical lens shapes for focusing synchrotron beams

Aspherical surfaces required for focusing collimated and divergent synchrotron beams using a single refractive element (lens) are reviewed. The Cartesian oval, a lens shape that produces perfect point‐to‐point focusing for monochromatic radiation, is studied in the context of X‐ray beamlines. Optical surfaces that approximate ideal shapes are compared. Results are supported by ray‐tracing simulations. Elliptical lenses, rather than parabolic, are preferred for nanofocusing X‐rays because of the higher peak and lower tails in the intensity distribution. Cartesian ovals will improve the gain when using high‐demagnification lenses of high numerical aperture.     

汉族儿童近视眼与角膜波阵面像差的相关性研究

目的 观察儿童眼轴长度（AXL）、角膜曲率（K）、前房深度（ACD）等屈光参数以及角膜高阶像差的变化特点。方法 收集64 例（64 眼）汉族近视儿童的资料（6～12 岁），以右眼为研究对象，采用散瞳验光测定屈光不正度数并计算等效球镜度数（SE）、角膜地形图测定并计算K 值、A 超测定AXL和ACD。角膜像差通过角膜地形图数据转换成Zernike多项式获得。所有病例均跟踪随访观察1 年，对比1 年前后的各参数的变化，分析各屈光参数与高阶像差间的相关性。结果 患儿1年后出现显著近视化方向漂移，以眼轴延长为主要特征，ACD 亦有显著加深，差异均有统计学意义（均P＜0.01）。角膜高阶像差则无显著变化（P＞0.05）。入选时角膜Zernike 3阶总像差与SE 显著相关（P＜0.01），Z（4,0）球差与SE 也显著相关（P＜0.05）。1年后，角膜像差与SE 及各屈光参数无显著相关性（均P ＞0.05）。结论 儿童在青少期近视化进展显著，且以眼轴延长为主要特征，而角膜高阶像差与近视化发展的相关性尚有待进一步研究。