磁浸没透镜的宽束曲轴像差分析的微分代数方法研究

微分代数是计算机数值分析领域中的一个非常有效的方法,可以实现任意高阶微分的准确计算.本文根据微分代数方法的基本原理,将其引入到磁浸没透镜的宽束曲轴像差的分析计算中,得到了任意阶曲轴像差的微分代数表达式.文中针对轴上磁场具有某种解析表达式的一个实际的磁浸没透镜系统,利用微分代数的曲轴像差分析方法,计算了它的曲轴像差,并给出了全部二阶和三阶几何像差的分布图形.     

真空电子技术

0463.1 2002060085磁浸没透镜的宽束曲轴像差分析的微分代数方法研究/程敏,唐天同,姚振华,王振华(西安交通大学电信工程学院)“电子学报.一2 002,30(6),一846一848微分代数是计算机数值分析领域中的一个非常有效的方法,可以实现任意高阶微分的准确计算.文中根据微分代数方法的基本原理,将其引入到磁浸没透镜的宽束曲轴像差的分析计算中,得到了任意阶曲轴像差的微分代数表达式.文中针对轴上磁场具有某种解析表达式的一个实际的磁浸没透镜系统,利用微分代数的曲轴像差分析方法,计算了它的曲轴像差,并给出了全部二阶和三阶几何像差的分布图形.…     

静电曲轴宽电子束二级几何像差及系数的计算

由二级近似下的曲轴轨迹方程出发,探讨了静电曲轴宽电子束二级几何像差及其系数,并给出了适于计算的形式.在大量管型计算的基础上,文中给出了两个实际管型的几何像差及系数的计算结果,并由此得出一级与二级几何像差的差异趋势,对实际像管的设计与计算具有一定的理论指导意义.     

基于渐近解的成像电子光学近轴横向像差理论及其验证

在成像电子光学系统的横向像差中,近轴像差是整个像面普遍存在、且影响图像中心像质的主要像差,并决定了系统的极限分辨率.本文由电子光学近轴方程的渐近解推导了近轴横向像差的普遍表示式,并通过一两电极静电同心球系统,推导了近轴轨迹特解的渐近解和精确解的解析表示,给出了二级和三级近轴色球差以及三级近轴放大率色差的表达式,证明了基...     

考虑二级近似下静电曲轴宽电子束聚焦系统的计算

本文对曲线坐标系下的静电宽电子束轨迹方程进一步深入研究，给出了该坐标系下的主轨迹方程以及考虑到二级近似下的曲轴轨迹方程，并将之转换成适合计算的形式。利用同心球系统论证了这种曲轴轨迹计算方法的合理性与可靠性，计算表明同心球近轴与实际轨迹之间、曲轴一级与二级近似下轨迹之间相差约在第五个数量级；由实际管型计算出的像差约在第四个数量级上，这在一般工程应用中是可以忽略的，但在高精度像管计算中却不能将之忽略。     

波动电子光学应用于宽电子束成象系统的研究

本文运用波动电子光学的理论,探讨了宽电子束成象系统中电子波的传播、成象、象差和电子光学传递函数(ETF)的问题。从光程函数出发,证明了一级色球差和三级几何象差可以用二级和四级光程函数来表达;论证了R—A公式只是普遍的一级色球差表示式用于系统轴上的结果;并基于变分原理导出了各种形式的电子轨迹方程。运用电子波函数,本文讨论了近轴区电子波传播的特性和理想成象性质;得到了“后焦面上的象乃是物面上的傅立叶变换”这一重要结论。进一步,还讨论了各种象差影响下的电子光学传递函数。     

均匀磁聚焦和周期磁聚焦部分屏蔽流过渡区的设计

本文叙述在均匀磁聚焦和周期磁聚焦部分屏蔽流过渡区设计的一种方法，指出于阳极电位与慢波线电位一同的电子光学系统，以及这两个电位虽然相同，但导流系数大，阳极孔效应严重的电子光学系统，它们的过渡区的设计，必须采用非等位空间中的傍轴电轨迹方程，并对用部分屏蔽流周期磁聚焦的电子光学系统，电子枪区中的电子轨迹与磁力线重合的问题提出了一些看法。     

宽束大物面电磁聚焦系统的弯曲轴电子光学像差理论

本文研究了宽束大物面电磁聚焦系统弯曲轴电子光学象差理论。我们引进了旋转的曲线正交坐标系,导出了主轨迹方程、一级近似的弯曲轴近轴轨迹方程,讨论了理想成象性质。本文定义了象差积分函数,导出了形式简洁的全部二级象差函数。     

静电圆锥透镜曲轴电子束聚焦理论的研究

在曲轴宽电子束聚焦理论的基础上，本文研究了静电圆锥透镜聚焦性质，提出了静电场中考虑主轨迹为平面曲线情况下电子束的焦点、焦距等电子光学基本参量的定义。作为例子，给出了两种类型的静电圆锥透镜的电子光学在不同电参量下的关系曲线。     

超大偏转角象差理论

本文采用曲轴电子光学理论,研究了超大偏转角情况下的偏转象差.给出了曲轴二级和三级象差公式.计算了均匀偏转场的曲轴二级、三级象差以及屏上光栅.并与一般直轴三级象差理论和解析公式的结果相比较.结果表明,随着偏转角的增大,曲轴三级象差的影响亦增大.当偏转角大于120°时,必须考虑曲轴三级象差的作用.     

Electron optical aberration calculations in a homogeneous magneticdeflection system with curved axis at extra-large defection angles

In the authors' previous paper, variational deflection aberration theory has been developed for nonhomogeneous magnetic deflection systems with curved axes at extra-large deflection angles. Based on the variational deflection aberration theory, a magnetic deflection system consisting of a homogeneous deflection field and a homogeneous sextupole field has been further investigated in the present paper. For such a magnetic deflection system, both the Gaussian trajectory and all second- and third-order aberrations have been calculated analytically and been expressed by algebraic-trigonometric formulae suitable for computer computations. It is to be expected that the present research and computational results may be useful in designing high-performance magnetic deflection systems for high-definition television color picture tubes with self-convergence     

Design of aplanatic waveguide Fresnel lenses and aberration-freeplanar optical systems

A modification of the waveguide Fresnel lens design that has phase-shifting zones placed on the curved contour is suggested. It is shown that the selection of a suitable shape for this contour allows coma aberration to be eliminated. Computer simulation results are presented to demonstrate the significant improvement of the optical characteristics for curved contour lenses. The aplanatic homogeneous refracting waveguide lenses are also considered. It is found that thick aplanatic refracting lenses and the proposed Fresnel lenses have field curvature aberration of opposite sign. This fact allows planar optical systems free from low-order aberration to be designed by combining refracting and Fresnel lenses. An algorithm for producing such a system is presented     

二元光学衍射透镜波象差分析

通过对衍射透镜一级衍射象的波象差分析,由比较系数方法导出其赛得和数.     

Variational aberration theory for magnetic deflection systems with curved axes at extra-large angles

Variational deflection aberration theory has been further developed for deflection systems with curved axes at extra-large deflection angles (up to 120/spl deg/). The variational method allows us to calculate second- and third-order deflection aberrations with respect to a curved axis by means of gradient operations on eikonal (the function of optical length). All second- and third-order deflection aberrations have been explicitly expressed in compact and appropriate formulae suitable for computer computations. It is to be expected that the variational deflection aberration theory may be useful in designing high-quality magnetic deflection systems for high-deflection television color picture tubes.<>     

Axially symmetric composite electromagnetic mirror for perfect axial-aberration correction

A new element of charged-particle optics is proposed and examined: an axially symmetric composite electromagnetic mirror employing a focusing magnetic field as well as an electrostatic one, the two fields overlapping. It is shown that the chromatic and spherical aberration coefficients of the mirror are opposite in sign to those found in conventional axially symmetric optics; their magnitude is twice the length of the paraxial particle trajectory as projected on the mirror axis of symmetry. As a result, the negative axial aberration coefficients can be varied over the wide range from a few millimeters to one meter with the mirror focal length and the particle energy being fixed. This property offers a way to fully compensate for the axial aberration of optimized ion or electron objective lenses in current use. A correction system incorporating the mirror is proposed. As compared with the sole correction arrangement used in electron optics, the system considered has about 1/5 times as many alignment degrees of freedom (mechanical and electrical) and should therefore display far greater stability; furthermore, it can work with ions as well as electrons.     

扫描电子束曝光机复合物镜的研究与设计

在综合研究已有的各种复合物镜(如移动物镜、变轴物镜和摆动物镜等)的基础上,本文对复合物镜的一般理论进行了探讨,推导了普遍化计算公式,并提出新的复合物镜(弯曲物镜)系统。采用解析函数近似表示系统场分布,对弯曲物镜系统象差进行了理论分析,并设计出一个实际系统。数值计算结果给出该系统在55mm2扫描场内,束孔径角5mrad和能散2.5eV下,最大彗差0.005m,横向色差0.001m。     

A unified aberration theory for magnetic deflection systems withrectilinear or curvilinear axes

A unified deflection aberration theory has been further developed for magnetic deflection systems with curvilinear or rectilinear axes. By using variational method, primary-order deflection aberrations with respect to curvilinear or rectilinear axis can be universally calculated by means of gradient operations on eikonal (the function of optical length). Conventional pure-order rectilinear-axis theory can be derived from a curvilinear axis eikonal of mixed-order in the rectilinear limit. By introducing general aberration integration functions in terms of mathematical operators, all primary-order deflection aberrations have been explicitly expressed in compact formulae suitable for computer computations. It is to be expected that the unified deflection aberration theory may be useful in designing high-quality magnetic deflection systems for high-definition television color picture tubes     

小型化同心反射式手机镜头设计

基于现代社会对手机镜头高像素、小型化的要求,基于同心透镜原理设计了同心反射式手机镜头。通过光路计算,求解了系统的球差表达式,进一步获得了系统的初始结构。利用光学设计软件设计了光学系统,镜头采用像元大小为1.25 μm的曲面传感器,光学系统的F数为1.8,焦距为2.7 mm,最大全视场角为100°,系统总长为2.7 mm。设计结果表明,在空间截止频率400 lp/mm处,0.7视场的调制传递函数均大于0.34,全视场的调制传递函数均大于0.23,各视场的弥散斑半径均小于艾里斑。在全视场内,相对照度高于0.64,该设计满足手机镜头成像要求。