一种高次光学非球面度的计算方法

针对现有光学非球面度计算方法不统一的问题,在分析常用方法特点的基础上,对于高次光学非球面度的计算提出最小最大残差法。寻找最接近球面,使其沿法线方向与非球面的最大偏离量最小,此时的最大偏离量即为非球面的最大非球面度。该方法适于计算机编程,计算结果准确,且可完全统一二次曲面和高次非球面的非球面度计算。     

用于非球面检测的球面计算全息图特性分析

通过对凸非球面检测过程中各部分元件对波面影响情况的分析,导出了球面计算全息图各衍射级次空间频率和滤波光阑最小孔径的计算公式, 证明了用球面计算全息图检测凸非球面可以减小计算全息图的特征尺寸,降低计算全息图的制作精度。根据导出公式选择合适的计算全息图的位相函数和滤波光阑孔径,以充分滤掉不需要的级次,实现凸非球面的全孔径检测。具体设计实例与实验结果表明,当选择直径为0.2mm的光阑和线宽在40靘到800靘之间变化的计算全息图时,实现了对孔径110mm, 球面半径500mm, 非球面系数为1的凸非球面镜的全孔径检测,这与分析结果完全吻合。     

非球面人工晶体设计及其光学性能研究

提出了非球面人工晶体的设计思路及方法,即根据个体人眼的角膜地形图,将其转换为波前图,获得Zemike系数Z40(球差)项,在该球差值基础上设计并得到非球面人工晶体结构参数.对植入9.5D和20.5D人工晶体的两实际患眼成像质量的模拟分析表明:以本丈方法设计的非球面人工晶体在对人眼系统的MTF,对比敏感度及离焦MTF的改善上都明显优于传统的球面人工晶体,光学性能良好.本文为非球面人工晶体的设计提供了切实可行的方法,并为其在临床上应用提供了一定的理论基础.     

大口径离轴非球面加工中能动磨盘面形分析

利用齐次坐标变换理论分析了计算机数控能动磨盘加工大口径离轴非球面反射镜时磨盘底面需要形成的实时面形,给出了通用的盘面实时轮廓的计算方法.以NST(新太阳望远镜)的离轴抛物面主镜参数为例.给出了用现有能动磨盘加工时盘面形状及磨盘变形量的计算结果,并将该方法用于两块轴对称非球面(Φ1 030 F/1.6椭球面和Φ1 250...     

非球面透镜技术的发展和应用

１非球面的历史现在很多镜头都采用了非球面，但它的普及时间并不长，也只不过１０年左右。非球面透镜的面精度要求很高，必须保证在亚微细粒级，故其产量较低、成本很高。非球面的制造方法最早是玻璃研磨方式，随着技术的进步，然后是玻璃模压法，后来是复合型法，现在已...     

非球面镜头技术的基础知识

引言 非球面镜头历史悠久,它在光学设计中的作用可追溯到１７世纪。 非球面透镜发挥上体的作用最早体现在 １９９２年发售的美能达ＡＰＥＸ９０照相机用的３８～９０ｍｍ镜头中,它包含了２面都是非球面的二片非球面透镜,作为变焦镜头实现了“理论最少构成数”——４片,达到了“小型化与低成本化两者兼具”。这以后迎来了９０年代非球面的全盛时代,即从高级镜头到普通镜头广泛地采用非球面。 面向２１世纪,非球面镜头的作用越发重要,并且有迹象表明,可以期待出现从未有过的非球面的新作用。１ 非球面镜头 球面透镜是指从透镜的中心到…     

非球面光学

何谓非球面光学?通常大部分光学系统的折射和反射面是平面或球面,因此我们称它们为球面光学。它与非球面光学正好相反。光学设计师是乐于使用非球面的。但是它受到一个条件限制,即只有非球面精度要求不高时造价才能降低(例如聚光镜)。如果非球面的精度要求很高的话,成本将大大超过球面系统。     

非共轴非球面光学系统计算软件设计

本文描述了一个非常规光学系统计算软件。光学系统可包括倾斜、偏心的球面和非球面。本文解决了一般非共轴光学系统初始数据建立问题,提供了光学系统图形显示,并对光线光路追迹结果进行了一些处理和讨论。     

基于非球面透镜组激光光束整形设计

本文针对激光显示领域激光光束光强均匀分布要求,本研究基于非球面透镜组激光光束进行整形设计。文中通过阐述激光光束光强均匀分布原理,着重论述了出射光束分布选择、线映射函数及球面参数确定3个非球面透镜组设计内容。在此基础上,选择匀化洛伦兹函数为输出光束的光强分布函数,展开实例设计分析,旨在基于该设计方法将入射光束准直的单模高斯激光光束整形为光强均匀分布的准直平顶激光光束。     

非球面等去除量磨抛加工中的变速运动模型

针对回转对称非球面的抛光工序,本文提出了一种点接触式的磨抛工艺以及实现等去除量磨抛加工的数控设备运动模型。磨抛工艺基于数控光学表面成形技术及Preston假设,采用筒形磨抛轮对回转对称非球面进行点接触式磨抛加工.在加工过程中,数控设备各轴的运动为变速运动,即工件的转速及磨抛轮的进给速度随着加工位置的改变而改变。通过对该变速运动模型进行求解,并由数控加工设备进行精确控制,从而实现等去除量的磨抛加工。实验结果表明,该变速运动模型能够很好地实现回转对称非球面的等去除量磨抛加工。     

环形子孔径拼接算法的精度影响因素分析

优化的拼接算法是环形子孔径扫描测量大口径非球面光学元件的关键问题。针对一种基于离散相位值的环形子孔径拼接算法,从精度评定判据入手,对随机噪声、高阶噪声、重叠区宽度及子孔径数目这几个主要影响因素进行了数值仿真分析。结果表明,该算法对高阶噪声和随机噪声均不灵敏,高阶噪声的影响略大于随机噪声的影响;对口径和相对口径较大的非球面,相邻子孔径间重叠系数应大于 0.15,对于非球面度不大的非球面,重叠系数可大于 0.25, 能以较高精度求得拼接参量。     

Capillary‐Assisted Fabrication of Biconcave Polymeric Microlenses from Microfluidic Ternary Emulsion Droplets

In this study, a simple capillary‐based approach for producing biconcave polymeric microlenses with uniform size and shape from ternary emulsion droplets is presented. Monodisperse ternary emulsion droplets (0.6–4.0 nL) are produced which contain a photocurable segment of an acrylate monomer and two non‐curable segments of silicone oil (SO) by using a microfluidic sheath‐flowing droplet generator on a glass chip. The curvature radius of the interfaces separating the droplet segments, as well as the droplet size, and production rate can be flexibly varied by changing the flow conditions of the organic and aqueous phases. Subsequently, off‐chip suspension photopolymerization yields non‐spherical polymeric microparticles with two spherical concave surfaces templated by two SO segments at random positions. By ultraviolet light irradiation of ternary droplets with two SO segments trapped by the interior wall of a cylindrical microcapillary (internal diameter: 130 μm), biconcave microlenses can be produced with two spherical concave surfaces with a common lens axis. The produced lenses are suitable for use as optical diverging lenses.     

人眼角膜参数计量校准与量值溯源方法研究

角膜曲率半径、屈光度和散光轴位是评价人眼角膜形态的关键参数。为解决人眼角膜参数准确测量和量值有效溯源,基于角膜反射成像原理,采用球面和环曲面设计形式,首次研制出人眼角膜参数系列标准。曲率半径测量范围为(5.5~10.0)mm,不确定度U=0.002mm(k=2);轴位测量范围为 0°~180°,不确定度U=1°(k=2)。建立了角膜曲率计工作基准装置国家计量标准,形成了人眼角膜参数量值传递与溯源体系。实验结果表明,该计量标准可以满足人眼角膜参数测量仪器的校准和量值溯源,保证人眼角膜参数的测量准确。     

二元平场透镜

讨论二元平场透镜的光学特性和象差。这种透镜不引入光焦度,当物体们我限远处孔径光阑与透镜重合时,不产生初级球差、彗差、轴用和轴外色差,但是它对场曲、畸变和轴上色差有贡献。给上用于校正双胶爱镜组的场曲的二元透镜实例。计算结果表明,二元透镜在平场光学系统中具有实用价值。     

小直径厚壁管材变曲率弯曲回弹预测

为快速、准确地预测管材变曲率的弯曲回弹,建立变曲率弯曲回弹预测的解析模型.基于ABAQUS平台建立小直径厚壁管材变曲率弯曲成形及回弹数值模拟模型,通过试验验证了所建模拟方法的可靠性.将变曲率回弹问题转化为离散定曲率回弹问题进行研究,通过近似纯弯曲回弹实验,建立管材定曲率弯曲回弹前后半径之间的函数关系式,将变曲率弯管轴线双圆弧拟合逼近离散,针对离散化的回弹弯管进行G1连续拼接,依据轴线复杂程度,构建拼接修正函数,建立管材变曲率弯曲回弹预测解析模型.通过2个试验算例验证该解析模型能够有效预测小直径厚壁管材平面变曲率弯曲回弹.回弹的准确预测是有效控制弯管回弹缺陷的前提,用于指导后续模具型面修正,补偿回弹误差,保证弯管几何精度.     

Test of a slow off-axis parabola at its center of curvature

We describe the interferometric testing of a slow (?/16 at the center of curvature) off-axis parabola, intended for use in an x-ray spectrometer, that uses a spherical wave front matched to the mean radius of the asphere. We find the figure error in the off-axis mirror by removing the theoretical difference between the off-axis segment and the spherical reference from the measured wave-front error. This center of curvature test is easy to perform because the spherical reference wave front has no axis and thus alignment is trivial. We confirm that the test results are the same as the double-pass null test for a parabola that uses a plane autocollimating mirror. We also determine that the off-axis section apparently warped as the result of being cut from the symmetric parent part.     

Dynamics of spherical metallic particles in cylinder electrostatic separators/purifiers

This paper presents a theoretical analysis of the dynamics of spherical metallic particles in electrostatic separators/purifiers (ESPs). The particle equations of motion are numerically solved in two dimensions using a computational algorithm. The ESPs consist of a pair of conductor cylinder electrodes. The upper cylinder is energized by HVdc, while the lower one is grounded and fixed horizontally on a revolvable axis. Some phenomena and aspects of separation process are explained and depicted including lifting off, impact, "motion collapse" and "sudden bouncing". The results reveal that the several phenomena depend on initial position, radius and density of the particle, curvature of the cylinder electrodes, distance between the electrodes and amplitude of the applied voltage. Optimization of the parameters is presented in order to get better separation/purification processes.     

Comparison of real and computer-simulated outcomes of LASIK refractive surgery

Computer simulations of alternative LASIK ablation patterns were performed for corneal elevation maps of 13 real myopic corneas (range of myopia, -2.0 to -11.5 D). The computationally simulated ablation patterns were designed with biconic surfaces (standard Munnerlyn pattern, parabolic pattern, and biconic pattern) or with aberrometry measurements (customized pattern). Simulated results were compared with real postoperative outcomes. Standard LASIK refractive surgery for myopia increased corneal asphericity and spherical aberration. Computations with the theoretical Munnerlyn ablation pattern did not increase the corneal asphericity and spherical aberration. The theoretical parabolic pattern induced a slight increase of asphericity and spherical aberration, explaining only 40% of the clinically found increase. The theoretical biconic pattern controlled corneal spherical aberration. Computations showed that the theoretical customized pattern can correct high-order asymmetric aberrations. Simulations of changes in efficiency due to reflection and nonnormal incidence of the laser light showed a further increase in corneal asphericity. Consideration of these effects with a parabolic pattern accounts for 70% of the clinical increase in asphericity.     

极浅压入下纳米压痕仪针尖面积函数校准方法的研究

采用原子力显微镜直接扫描纳米压痕仪针尖法、球面拟合法和熔融石英标准样块的间接测量法对极浅压入下纳米压痕仪的针尖面积函数进行比较分析。实验表明,在极浅压入下,原子力显微镜直接法由于真实地反映了针尖尖端的几何形貌因而获得的面积函数更为准确可靠。建立了相应的数学模型,对于直接法测量中主要的误差,即由于原子力显微镜针尖曲率半径带来的误差进行了分析,结果表明在极小压入深度下压入深度越小,原子力显微镜针尖曲率半径带来的压痕仪针尖面积函数相对误差越大。