Aberrations of plane-symmetric multi-element optical systems

Based on a recently developed aberration theory of plane-symmetric grating systems, its aberration coefficients are firstly extended to be applicable to the plane-symmetric refractive optical surface. To justify the linear approximation of aperture ray in a multi-element system, the ray aberrations of double-element systems with the third-order accuracy of aperture ray are derived and expressed as the form of wave aberrations. The numerical comparisons are then made between the ray tracing, the aberration expressions with the linear and with third-order accuracy of the aperture ray. Moreover, the modifications of the wave and ray aberrations are discussed in the paper when the position of the principal ray changes.     

偏心和倾斜光学系统的像差特性

运用一种新的分析偏心和倾斜光学系统初级像差特性的方法—矢量像差理论,分析了具有较大交叉倾斜角的平行平板光学系统和具有较大倾斜角的光楔光学系统的像差特性.通过ZEMAX光学设计软件像差分析功能中的垂轴像差曲线、场曲曲线和点列图加以比较,两者非常吻合,证明该理论可以对具有较大倾斜元件的非共轴光学系统设计起指导作用.     

A mathematical model of Schmidt corrector plate with defocus in variable for quick F ratio and large aperture systems

To make it easier for designing Schmidt optical systems, based on wavefront aberration functions, a mathematical model of the corrector plate aspheric surfaces varies as a function of defocusing amount is established. It corrects not only the third-order spherical aberration, but also the 5th-order spherical aberration for the system. A series of Schmidt optical systems were designed as examples to evaluate the mathematical model of the aspherics. Results show that the mathematical model is precisely in fitting the needed shape of the corrector, and can be used for the systems for quick F ratio and large aperture. A mathematical model for reflective correctors shape is also established.     

Design of unobscured reflective zoom system with three mirrors

A method for the design of an unobscured reflective zoom system with three mirrors is described. This method applies the vector aberration theory, which helps designers analyze third-order aberrations for optical systems with decentered and tilted surfaces. As the vector aberration theory presents the variation of third-order aberrations in asymmetric systems through analytic expressions, real ray tracing is unnecessary. Hence, the design with vector aberration theory is faster, and the analytic expressions are more comprehensive and intuitive. To demonstrate the practicability of the method, a design example is given, which shows that the presented method can guide designers achieve a good unobscured reflective zoom system with three mirrors.     

自由曲面空间光学系统设计研究

对自由曲面的发展及应用做简要梳理,介绍国外自由曲面空间光学系统的研究现状,讨论3种自由曲面数理模型的特点和像差平衡能力,阐述自由曲面光学系统相对轴对称系统和平面对称系统的像差特点以及自由曲面空间光学系统的像差控制与评价方法,给出采用泽尼克多项式表述的自由曲面多光谱相机的设计结果,成像视场76,为远心光路设计,全视场调制传递函数（MTF）优于0.56,适用于空间多光谱成像。     

基于伽利略结构的二级激光扩束系统的设计

针对高倍率扩束系统设计要求(即轴上和轴外像差都得到较好的校正),从三级像差理论出发,设计了一种新型的40^×高倍率激光扩束系统。该系统是基于简单的伽利略结构并通过二级扩束系统来实现的,系统包括4片透镜,通过引入2个二次非球面、 2个反射镜或1个棱镜来折叠光路。利用CODE V光学设计软件给出了该系统的光学结构参数和外形结构图,并进行了像质评价。结果表明：该系统结构简单,设计难度小,成本较低,像质好,性能优良,是一种可以被广泛采用的高倍率激光扩束系统。     

Conditions for identical position of optimal image plane for axial imaging with different values of f-number

By analysis of the dependence of longitudinal spherical aberration on the numerical aperture, it is possible to find such values of the numerical aperture, where spherical aberration is zero. Such values of the numerical aperture are called correction zones. The work theoretically analyses the described problem and equations are given for wave aberration coefficients using correction zones for spherical aberration of the third and the fifth order. Our work presents an analysis of optimal values of correction zones and an optimal position of the center of the reference sphere based on the variance of wave aberration for the image quality evaluation. Relations are described for calculation of correction zones of an optical system having an identical position of the optimal image plane for two values of the f-number. The analysis of optical systems using correction zones is performed on an example.     

三反射主动变焦系统设计

空间光学系统在对深空探测、监视、威胁侦测和对地高分辨率侦查等应用中,不仅需要能同时获得高分辨率和宽视场范围的变焦系统,还需要体积小、重量轻、低能耗及快速调焦的系统,传统机械变焦系统因需要复杂精确的机械运动控制而存在诸多问题.因而,基于主动光学理论,将主动光学元件应用到成像系统中,提出了通过某个或某几个光学元件的曲率半径变化实现系统焦距变化的理论.根据初级像差理论和系统的外形尺寸,研究了系统主动变焦原理,确定了初级像差方程组的约束条件,求解共轴主动变焦系统的初始结构参数,借助ZEMAX软件进行优化设计,设计了一个由静止的主镜、曲率半径作为变量的次镜和三镜、无光焦度的平面镜组成的三反射主动变焦系统.由于该共轴三反射主动变焦系统存在两次遮光,会影响系统像面能量的接收,因此,指出对共轴系统进行无遮拦离轴优化设计的必要性,讨论了离轴系统设计理论,并设计了离轴三反射主动变焦系统.     

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     

Studies on third-order nonlinear optical properties and reverse saturable absorption in polythiophene/poly (methylmethacrylate) composites

We report here the studies on third-order nonlinear optical properties of two novel polythiophene composite films investigated using the Z-scan technique. The measurements were carried out using a Q-switched, frequency doubled Nd:YAG laser producing 7 nanosecond laser pulses at 532 nm. Z-scan results reveal that the composite films exhibit self-defocusing nonlinearity. The real and imaginary parts of the third-order nonlinear optical susceptibility were of the order 10⁻¹² esu. The effective excited-state absorption cross section was found to be larger than the ground state absorption cross section, indicating that the operating nonlinear mechanism is reverse saturable absorption (RSA). The polythiophene composite films also exhibit good optical power limiting of the nanosecond laser pulses. The nonlinear optical parameters are found to increase on increasing the strength of the electron-donor group, indicating the dependence of χ ⁽³⁾ on the electron-donor/acceptor units of polythiophenes.     

Design method of soft X-ray and vacuum ultraviolet optical system based on plane-symmetric aberration theory

Optical Review - Soft X-ray and vacuum ultraviolet optical system has the imaging performance of plane-symmetric optical system, this paper propose a design method of this kind of optical systems...     

非球面目镜

由于孔径光栏（出瞳）在目镜光学系统的外面，所以光学系统的畸变矫正格外地困难。消除畸变的最佳方法是采用非球面。本文依据三级像差理论，对新颖的非球面广角目镜的光学系统设计作了描述，并给出设计的结果和数据。     

Total ionisation cross sections for chlorofluoromethanes and CClx radicals by electron impact

We report here the total ionisation cross section for chlorofluoromethanes, namely CCl₃F (Freon 11), CCl₂F₂ (Freon 12), CClF₃ (Freon 13), CHCl₂F (Freon 21), CHClF₂ (Freon 22), CH₂ClF (Freon 31), CCl₄ and CCl_x (x = 1–3), radicals by electron impact from ionisation threshold to 2 keV. The total inelastic cross section is obtained employing a complex optical potential formalism and solving the Schrödinger equation through partial wave analysis. Using the complex scattering potential-ionisation contribution method, the total ionisation cross section is derived from the inelastic cross section for these targets. The results obtained are then compared with the existing experimental and theoretical data, wherever available. The present result shows reasonable agreement with previous data. For the CCl_x radicals, the ionisation cross section is predicted for the first time. The data reported here have immense interest to atmospheric and technological plasma modelling.     

Research on reflective zoom system with 3 mirrors

This paper uses the third-order aberration theory to design a reflective zoom optical system. The advantage of this method is that, by solving a set of Seidel aberration coefficient functions, it allows the designer to achieve the initial construction parameters of the optical system, i.e., radii of curvature and separations between mirrors, etc. In order to verify the accuracy of this method, a prototype of a coaxial zoom optical system with three mirrors is designed. This paper introduces the manufacturing process of the prototype in detail, describes the procedures of aligning and experimenting, and analyzes the experiment results in the end. In this way, the feasibility of this method is confirmed.     

Design of off-axis reflective projection lens using spherical Fresnel surface

In this paper, an off-axis reflective projection lens with single Fresnel reflective surface and three aspheric surfaces were designed. The design method of reflective lens using spherical Fresnel surface is discussed. The MTF (Modulation Transfer Function) of the off-axis reflective lens, with optical magnification 100×, F-number 2.5 and field of view 120°, is over 40% at 0.6 lp/mm on the image side, the distortion is less than 2%. This design method can provide reference for application of Fresnel surface in wide field of view imaging, and possesses a bright future with the continuous development of fabrication technique.     

Third-order aberration analysis of an off-axial optical system

The aberration theory applied to co-axial optical systems is extended to off-axial systems, for which third-order aberration coefficients are considered. The derived aberrations are analyzed using three-dimensional ray bundles, spot diagrams, and image charts, and classified in relation to the system symmetry. This theory is very useful for optical designers, allowing them to clarify the relationship between the structures of off-axial optical systems and the corresponding off-axial aberrations.     

一种凸非球面镜补偿检验的新方法

凸非球面检验是光学检验中一个比较困难的问题。结合一块Φ110mm的凸双曲面镜,在分析几种传统检验方法的基础上,提出了一种用透镜组补偿检验凸非球面的新方法。令球差系数∑S1=0,用三级像差理论求解光学系统的初始结构,并通过Zemax光学设计软件对初始结构进行优化,克服了传统检验方法的缺点和不足。从设计结果可以看出,系统的像差得到了很好的校正,使得凸双曲面达到了很高的检验精度,从而使非球面的检验更加方便。     

Production of colored scalar particles in <Emphasis Type="Italic">pp</Emphasis> collisions and masses of scalar gluons from future LHC data

The production of pairs of scalar particles belonging to an arbitrary color multiplet of the SU _c (3) group in proton-proton collisions is considered, and the differential and total cross sections for the corresponding partonic processes are obtained. The total cross section for the production of octets of scalar gluons F ₁ and F ₂ at LHC is calculated versus their mass, and their dominant decays, which are necessary for their searches, are discussed. It is shown that, for mF ₁ ≲ 1000 GeV, the number of signal $ t\tilde tb\tilde b $ t\tilde tb\tilde b events fromthe decays of the scalar gluon F ₁ may exceed substantially (by not less than three standard deviations) the Standart Model background and that the cross section for the production of scalar gluons F ₁ and F ₂ having masses in the region m _F1,m _F2 ≲ 1300 GeV may be sufficient for the efficient (N _events ≲ 100–1000 at L = 10–100 fb⁻¹) production of these particles at LHC.     

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。     

高能光纤激光经准直系统后的光束质量研究

应用光线光学的理论,对透镜的几何像差、热非线性等因素对光纤激光光束质量的影响进行了分析和计算,给出了激光通过多透镜光学系统后,光束质量参数M²与系统参数的一般关系. 研究了高能光纤激光通过准直系统后的光束质量. 研究结果表明,随着激光功率的增大,经准直系统后光束的光束质量存在最佳值,其对应的激光功率与准直系统参数有关,为高能光纤激光准直系统的设计提供了参考. 关键词： 高能光纤激光 光束质量 准直系统 光线光学