基于矢量波像差理论的两反光学系统装调研究

 为了实现对两反光学系统的精密装调,提出一种基于矢量波像差理论和波像差检测技术对失调量精确求解的装调方法。使用矢量波像差理论,将已设计的两反光学系统参数、失调量和失调光学系统的波像差之间建立方程;然后通过干涉测量法得到某一个视场的干涉图,利用条纹分析软件得到表征失调系统三阶彗差和三阶像散的泽尼克项系数,将泽尼克项系数代入方程从而求解出失调量。运用此方法对4 m口径RITCHEY-CHR-TIEN结构的天文望远镜进行模拟装调,最终求解的失调量与引入的失调量结果相互吻合,说明该装调方法正确。     

大视场离轴三反光学系统场曲特性与装调方法

基于矢量波像差理论,分析了离轴三反光学系统装调过程中在小量失调状态下的场曲特性,提出了通过倾斜焦面补偿系统失调产生场曲的方法。在此基础上,结合某遥感相机进行了仿真模拟,具体分析了焦面分视场数目与三反射镜安装精度要求的关系,提出了系统装调流程和方法。利用测试相机调制传递函数的方法,对相机的场曲特性进行了测试,并通过修正焦面倾角实现场曲像差补偿。修正后的相机边缘视场调制传递函数得到明显提升,相机各视场调制传递函数均优于0.21。     

利用离轴三反镜光学系统确定各镜的装调公差

利用条纹泽尼克系数与赛德尔像差的关系,在三反镜光学系统的出瞳面上,用条纹泽尼克系数来表示系统的波像差。通过光学设计软件Zemax计算得到三反镜光学系统各镜的装调公差,以公差要求高的镜面作为装调基面,从而减少要调整的自由度。通过分析泽尼克(Zernike)系数在公差范围内的变化幅度来确定光学系统在出瞳面上各个像差的变化幅度,用该幅度的变化量来决定主次三镜各自由度在各个方向上的敏感度,最终确定各个自由度的优化调整级别。对一大口径无遮拦离轴三反镜光学系统进行了装调,在波长λ=632.8nm的条件下进行了检测。结果表明:整个光学系统全视场波前误差的均方根值RMS=0.108λ。     

面对称光学系统的初级波像差理论研究

非旋转轴对称光学系统波像差理论的建立有利于理解旋转 轴对称光学系统的装调误差和离轴三反射光学系统等非旋转轴对称光学系统的选型设计. 本文利用旋转轴对称球面光学系统的全口径初级波像差理论推导了子孔径面对称光学系统的初级波像差分布公式, 证明了面对称光学系统中的节点像差理论, 即除球差外的所有初级像差的零值节点偏离视场中心, 而不再是视场的旋转对称函数; 并首次阐述了多零值节点初级非对称像差产生的根源和变化特性. 该理论可以有效指导非对称光学系统初始结构的选择和优化设计过程. 关键词： 面对称 像差 几何光学     

用像差逐项优化法装调离轴三反射镜光学系统

在对复杂光学系统粗装调完成之后 ,利用自准干涉检验的办法 ,采集光学系统各视场的干涉图 ,然后用干涉条纹分析软件算出整个系统波前误差 ,其量值用泽尼克系数来表示 ,通过泽尼克系数与系统的波像差的关系 ,判断要调整的目标值 ,即当前在光学系统中占主导地位的波前误差 ,对主导误差优化 ,得到系统的失调量 ,由光学设计软件确定其正确后 ,进行一次精密装调。然后进行多次这样的计算机迭代和优化 ,直到光学系统达到最好的调整状态。运用此方法来装调大口径 ,长焦距离轴三反射镜系统 ,在波长λ等于 6 32 .8nm时 ,该离轴三反射镜系统中心视场波像差均方根值达到了 0 .0 94λ ,+1°视场和 - 1°视场的均方根值分别为 0 .10 6λ和 0 .12 5λ。     

新型离轴反射变焦距光学系统的多视场检测方法

基于对离轴反射变焦距光学系统进行计算机辅助装调研究, 需要检测离轴反射变焦距系统各个视场的波像差, 除零度视场外, 获得包括其他视场的波像差有助于提高计算机辅助装调的准确性, 但是目前已有的波像差检测方法往往只能获得系统零度视场的波像差. 本文针对这个难题提出了一种检测离轴反射变焦距光学系统各个视场波像差的方法, 并应用于离轴三反变焦距光学系统的各视场波像差仿真检测. 该方法在传统自准直干涉法的基础上进行改进, 关键在于采用变形镜代替扫描的平面镜, 并采用夏克-哈特曼波前传感器代替干涉仪, 配合精确标定的激光器光源阵列, 可以实现对离轴三反变焦距光学系统的多视场波像差同时检测. 由理论分析和仿真模拟得出, 该系统在视场(0°, 3°), (0°, 4.2°), (0°, 5.5°), (0°, 7°), (0°, 9.8°), (0°, 14°)处经过变形镜补偿后的剩余波像差的RMS值分别为0.00039λ, 0.00075λ, 0.0024λ, 0.00017λ, 0.00053λ, 0.0057λ, 分析仿真结果表明此检测方案是可行的, 且适用于离轴反射变焦距系统的计算机辅助装调技术的研究.     

折轴三反射光学系统的计算机辅助装调技术研究

 给出计算机辅助装调中失调量与像差关系的数学模型,利用Zemax对折轴三反射光学系统进行失调仿真,得到失调数据,再对数据进行分析和处理,求得次镜和三镜的灵敏度矩阵,还对各种初级像差与各装调参量之间的对应关系及该系统的失调特性进行讨论。根据以上分析结果,最终确定了共轴三反射光学系统的装调方案。为了验证方案的可行性,在Zemax中对共轴三反射光学系统人为地加入不同的失调量后,按照确定的装调方案,利用建立的计算机辅助装调数学模型计算出失调量的大小和方向,再根据计算结果对共轴三反射光学系统进行调整,仿真结果和实际装调结果都证明该方案是可行的。     

光学仪器 光学仪器装调

TH706 2005043174 利用离轴三反镜光学系统确定各镜的装调公差=Study on decision of alignment priority using mirror tolerance in a three mirror off-axis optical system[刊,中]／杨晓飞(中科院长春光机所,吉林,长春(130022)),韩昌元／／光学技术,-2005,31(2),-173-176 利用条纹泽尼克系数与赛德尔像差的关系,在三反镜光学系统的出瞳面上,用条纹泽尼克系数来表示系统的波像差。通过光学设计软件Zemax计算得到三反镜光学系统各镜的装调公差,以公差要求高的镜面作为装调基面, 从而减少要调整的自由度。通过分析泽尼克(Zernike)系     

共轴三反光学系统卧式装调技术

共轴三反光学系统是空间光学遥感器常用的设计形式，以“高分一号”遥感卫星高分辨率相机装调为例，对共轴三反系统计算机辅助装调技术进行了研究。提出以主镜光轴为装调基准，通过调整三镜控制系统视场和调整次镜控制系统像差的装调方法，分析了次镜和三镜的失调量与Zernike系数变化关系，由光学设计软件求得系统灵敏度矩阵，用于指导系统装调工作，提高了装调精度，缩短了装调周期。测试结果表明:光学系统各视场Zernike系数优于0.05λ，系统波相差RMS值优于0.06λ，系统通过在轨成像测试，图像清晰，层次丰富。     

基于矢量波像差理论的两反系统装配失调解算方法

以矢量波像差理论中的三级像差理论为基础,提出了一种两反系统装配失调量解算方法。该方法仅采用轴上视场波前像差系数建立失调量解算模型,然后基于球差系数解算间隔误差,并基于彗差和像散系数解算偏心和倾斜误差,大幅提高了解算精度和效率。以某一两反光学系统为例,利用光学设计软件Zemax进行模拟装调,系统轴上视场失调像差系数均减小到10~(-7)数量级,失调误差均校正到10~(-5)数量级,达到了良好的装调效果。最后,利用该失调量解算模型指导两反光学系统的装调,失调量解算精度及装调精度达到了使用要求。Zemax模拟装调结果和实际装调效果均证明了所提方法的正确性。     

Third-order aberration analysis of tilted-pupil optical systems

The aberration field of an optical system with a tilted pupil is explored through expanding the vector expressions of the third-order wavefront aberrations. First, the vector forms of the wavefront aberrations are modified to obtain the aberration expressions with the pupil tilted; full field displays of coma and astigmatism in this situation are given. Then, the third-order aberration formulas with the pupil decentered and tilted simultaneously are derived and discussed. Finally, an example is taken to certify the validity of aberration distribution properties.     

Aberrations of self-imaged patterns with two-dimensional periodicity

We develop a geometrical theory of aberration in the self-imaged patterns with two-dimensional periodicity. The patterns are considered to be a crossed-line grating or a periodic array of finite apertures. We first derive the raytracing equations for determining the optical path of a self-imaging ray. We then find the third- and fifth-order contributions to the wavefront aberration which arise from the difference between the optical paths of a self-imaging ray and of an actual ray. We also derive the expression of the ray aberration from the wavefront aberration. The ray aberration is classified into five distinct types by analogy with the cases in a refracting lens system. We show that the overall ray aberration is entirely undercorrected and the aberrated image patch is decentered from an ideal image point in the direction parallel to the direction tangent vector of a chief ray. The image evaluation technique discussed here will be useful in various applications related to self-image formation of two-dimensionally periodic patterns.     

Aberration theory of plane‐symmetric grating systems

Aberration theory of plane‐symmetric optical systems of mirror and grating has been developed based on the wavefront aberration method. A toroidal reference wavefront surface is used to define the wavefront aberration. Based on the ray geometry, the coordinate mapping relationships of the ray between the optical element and the incident and aberrated wavefronts are derived using a polynomial‐fit method; this enables the resultant coefficients of the wavefront and the transverse aberration to be kept to the fourth‐order accuracy of the aperture‐ray coordinates. By setting up the transfer equations of the field and aperture rays, the contribution to wavefront aberrations from each mirror and grating can be added to make the aberration calculation of multi‐element systems feasible. The theory is validated by the analytic formulae of the spot diagram.     

光束斜入射的折反射组合光学系统的像差计算

基于平面对称光栅反射镜系统的像差理论,根据光学元件材料折射率对成像光束波像差进行修正,将像差理论扩展到平面对称折射光学系统,使得该理论可应用于光束斜入射的折反射组合光学系统的像差计算;指出在折反射组合光学系统中考虑物像方空间折射率的关系,以及入射角方向的定义,使得波像差的计算表达式保持统一;应用扩展后的像差理论对折反射椭球镜面形检测光学系统进行像差分析计算,并与Zemax光线追迹结果进行对比,验证波像差理论的有效性。该像差理论为光束斜入射的折反射组合光学系统的设计、像质评价及优化提供了有效的分析手段。     

Individual eye model based on wavefront aberration

Based on the widely used Gullstrand-Le Grand eye model, the individual human eye model has been established here, which has individual corneal data, anterior chamber depth and the eyeball depth. Furthermore, the foremost thing is that the wavefront aberration calculated from the individual eye model is equal to the eye's wavefront aberration measured with the Hartmann-shack wavefront sensor. There are four main steps to build the model. Firstly, the corneal topography instrument was used to measure the corneal surfaces and depth. And in order to input cornea into the optical model, high-order aspheric surface-Zernike Fringe Sag surface was chosen to fit the corneal surfaces. Secondly, the Hartmann-shack wavefront sensor, which can offer the Zernike polynomials to describe the wavefront aberration, was built to measure the wavefront aberration of the eye. Thirdly, the eye's axial lengths among every part were measured with A-ultrasonic technology. Then the data were input into the optical design software–ZEMAX and the crystalline lens's shapes were optimized with the aberration as the merit function. The individual eye model, which has the same wavefront aberrations with the real eye, is established.     

基于双波前传感器自适应光学技术的太阳光栅光谱仪

为了研究不同太阳大气高度的热力学特性,具有良好成像质量的成像型光栅光谱仪是实现这个目标的重要仪器。然而作为地基式太阳望远镜重要的终端仪器之一,光栅光谱仪的光谱成像性能不可避免的会受到动态波前像差和系统静态像差的影响。动态波前像差常通过在太阳望远镜系统中集成自适应光学系统进行补偿。针对光学系统中的由装调和光学元件加工等引起的静态波前像差,提出了一种基于自适应光学技术校正光栅光谱仪中静态波前像差的方法,并进行了数值模拟仿真和实验验证。实验结果表明,校正后系统的残余波前像差RMS≈0.025λ,此时波前像差对光谱分辨率和能量利用率的影响可忽略,提高了光栅光谱仪的光谱成像质量,证明了所提出的方法的有效性。此外它具有降低光学系统装调精度和光学元件加工精度要求的优点。     

Design strategy for flat-field Schmidt optical system

The present study provides the theory base for designing flat-field Schmidt optical systems, based on the wavefront aberration of Petzval field curvature, a mathematic model of the Petzval radius is setting up. The radius of Petzval image surface is not equal to the focal length of the primary mirror or the focal length of the system. An aberration balancing method for flat-field Schmidt optical systems design is proposed: did not change parameters of the corrector, through adjusting the distance between the plate and the mirror to realize aberration equilibrium. The total physical track is more compact than equilibrium before.     

Wavefront aberrations in the accommodated human eye based on individual eye model

In this research, we firstly construct individual eye models based on the wavefront and the measured cornea structure of the eyes. Then we analyze the influence of accommodation on the wavefront aberrations based on individual eye model. The individual eye model has the same wavefront aberration as that measured from Hartmann–Shack wavefront sensor. The optical design software ZEMAX is used to construct the individual eye models for 20 normal eyes. Accommodative conditions are from 0 to –4 diopter in steps of one diopter. The variations of the total, the spherical, the coma and the higher-order root-mean-square wavefront aberrations, as accommodations, are illustrated. Influence of accommodation on wavefront aberration varies from individual to individual, and the variation magnitude is independent of the magnitude of the wavefront aberration of the eye.