人眼波前像差的动态特性研究

人眼波前像差随时间涨落会引起人眼光学性能和视觉功能的改变.采用改进的HartmannShack波前传感器人眼像差仪对10只屈光度为0D~-5.0D、直径为3mm和6mm的人眼瞳孔的波前像差进行测量,其中每只人眼在5s内连续测量125次,测量频率为25Hz.为确定测量过程中是否引入人为像差,对人造眼3mm和6mm瞳孔的动态波前像差进行测量比对.结果表明:所测量的10只人眼3mm和6mm瞳孔总的Zernike波前像差均方根涨落幅度的平均值分别为0.087μm和0.105μm,均大于Marechal衍射极限;Zernike第3阶到第7阶波前像差均方根涨落幅度随像差阶数的递增而下降,涨落幅度为0.06~0.02μm;人眼波前像差的涨落频率达6Hz.     

Analysis of pupil and corneal wave aberration data supplied by the SN CT 1000 topography system

Ocular aberrations depend on pupil size and centring and the retinal image quality under natural conditions differs from that corresponding to laboratory ones. In the present article, pupil and wave aberration data supplied by the Shin Nippon CT 1000 (SN CT 1000) topography system are analysed. Two groups of eyes under natural viewing conditions are considered ((260±20) lux at the eye under study). The first group consists of 10 normal eyes (−1.25 to 3 D sphere; 0 to −1.75 D cylinder) of five young subjects (age between 18 and 33 years). For this group, five determinations per eye are performed and the repeatability of results is analysed. Pupil centre is displaced from corneal vertex towards the temporal region, the largest displacement being (0.5±0.1) mm. The variation of pupil diameter in each eye is less than 21% while the inter-subject variability is large since diameters are between (3±0.3) and (5.3±0.6) mm. Aberrations are evaluated for two different pupil sizes, the natural one and a fictitious one of 6 mm. The corneal higher-order root-mean square wavefront error (RMS_HO) for a 6 mm pupil centred in the corneal vertex, averaged across all eyes, is (0.37±0.06) μm while, considering the natural pupil diameter, the average in each eye is significantly lower, up to eight times smaller. The fourth-order spherical aberration is an important aberration in the considered eyes, its maximum value for a 6 mm pupil being (0.38±0.02) μm. The second group consists of 24 eyes of 12 subjects (age between 25 and 68 years) such that four eyes are of normal adults (1.25 to +6 D sphere; 0 to −0.5 D cylinder), eight have astigmatisms (−5.5 to +3.25 D sphere; −1.5 to −4.5 D cylinder), six have post-refractive surgery (+0.5 to +3.5 D sphere; −0.5 to −4 D cylinder) and six have keratoconus (−9.5 to +1 D sphere; −1 to −4.5 D cylinder). For this group only one determination per eye is performed. Pupil centre is displaced from corneal vertex towards the temporal region except in cases of keratoconus, where there can be a dominant upwards displacement. Pupil diameters are between 2.7 and 5.6 mm. The corneal higher order root mean square wavefront error for a 6 mm pupil ranges between 0.3 (normal eye) and 5.3 μm (keratoconus).     

部分相干平顶高斯光束通过球差透镜的聚焦特性

 基于部分相干光的传输理论，研究了部分相干平顶高斯光束通过球差透镜聚焦后轴上点的光强分布。数值计算表明:轴上最佳聚焦点随着球差从负到正的变化而向几何焦点方向移动；光束阶数越大，实现最佳聚焦点越过几何焦点所需的正球差值越小；正负球差对应的最佳聚焦点始终分居于无球差时最佳聚焦点的两侧;轴上最佳聚焦点的光强随着球差从负到正的变化而变小；当正负球差绝对值较大时，光强随球差的变化较为缓慢，而在球差值为0附近，光强随球差的变化比较剧烈。     

左手性介质透镜系统的赛德尔像差特性研究

根据初级像差理论，系统研究了由左手性介质构造的透镜系统的赛德尔像差特性.分析了左手性介质单折射曲面的赛德尔像差特性，发现其消初级球差的曲面类型比普通介质更为灵活且可用于实成像系统.依据薄透镜赛德尔和数公式，分析和设计了三种只有左手性介质才具备的可消部分赛德尔像差的薄透镜结构参数，提出了几种能同时消除全部五种赛德尔像差的由左手性介质构造的透镜组合系统.研究表明左手性介质相对于普通介质在消像差方面存在较大优势，在光学设计时可以采用更少的折射表面个数或更简单的表面形状即可到达同等的成像性能.     

On the theory of temporal aberrations for cathode lenses

A new approach to the theory of temporal aberration for cathode lenses is given in the present paper. A definition of temporal aberration is given in which a certain initial energy of electron emission along the axial direction ε_z1 (0ε_z1ε_0max) is considered. A new method to calculate the temporal aberration coefficients of cathode lenses named “direct integral method” is also presented. The “direct integral method” gives new expressions of the temporal aberration coefficients which are expressed in integral forms. The difference between “direct integral method” and “τ-variation method” is that the “τ-variation method” needs to solve the differential equations for the three of temporal geometrical aberration coefficients of second order, while the “direct integral method” only needs to carry out the integral calculation for all of these temporal aberration coefficients of second order.All of the formulae of the temporal aberration coefficients deduced from “direct integral method” and “τ-variation method” have been verified by an electrostatic concentric spherical system model, and contrasted with the analytical solutions. Results show that these two methods have got identical solutions and the solutions of temporal aberration coefficients of the first and second order are the same as with the analytical solutions. Although some forms of the results seem different, but they can be transformed into the same form. Thus, it can be concluded these two methods given by us are equivalent and correct, but the “direct integral method” is related to solve integral equations, which is more convenient for computation and could be suggested for use in practical design.     

Review of Recent Zoom Lens Developments for 35 mm Cinematography at Panavision

A series of high performance zoom lens objectives developed by Panavision over fifteen years, which are very popular in the motion picture (cine) industry, are described. Various aspects of four cine zoom lenses, including; definitions, development, specification, construction, aberrations and tolerances, are discussed.This paper was originally presented at the 2nd International Conference on Optical Design and Fabrication, ODF2000 which was held on November 15-17, 2000 at the International Conference Center, Tokyo, Waseda University, Japan.     

MS-Untersuchung der Leberfunktion mit 15NH3

Dose response curves for lymphocyte chromosome aberration frequencies using X- and gamma radiations became an important and reliable indicators as biological dosimeters especially in radiation accidents and professional over exposures. Nowadays electron beams therapy are frequently used for their advantages in cases of tumours under or near to the body surface. Dose-response curves for these electron beams are rarely published. Human peripheral blood lymphocytes were in vitro irradiated with various low and high doses (0.1 Gy to 4.9 Gy) of 18 MeV electron beam to utilize such a dose-response curve using chromosome aberration frequencies as a biological marker. Then we compared this biological curve with physically obtained curves normally used in planning for radiotherapy treatment. It is interesting to find a significant difference between both of them. The biological curve is generally higher in value and that the aberrations induced by 93% of a dose is significantly higher and deeper in site than those aberrations induced by the 100% dose calculated physically. If the above observation is confirmed by detailed studies, it would be of importance to the radiotherapist to plan for isodose curves according to biological determinations.

Dosis-Wirkungs-Kurven der Mutationsraten von Lymphozyten Chromosomen bei dcr Anwendung von Röntgen- und Gammastrahlen sind wichtige und verläβliche Indikatoren in Form von biologischen Dosimetern, insbesondere bei Strahlenunfällen und bei berufsbedingten Überbestrahlungen. Gegenwärtig werden häufig auch Elektronenstrahlen wegen ihrer Vorteile bei der Therapie von Tumoren unter oder in der Nähe der Körperoberfläche eingesetzt. Dosis- Wirkungs-Kurven für diese Elektronenstrahlen werden nur selten veröffentlicht. Peripherisehe Bhutlymphozyten des Menschen wurden in vitro mit verschiedenen niedrigen und hohen Dosen (0,1 Gy … 4,9 Gy) von IS MeV-Elektronen bestrahlt, um solche Dosis-Wirkungs-Kurven als biologische Anzeiger für die Chromosomen Mutationsraten zu erhalten. Wir haben dann diese biologische Kurve mit physikalisch erhaltenen Kurven verglichen, die normalerweise bei der Planung radiotherapeutischer Behandlungsmaβnahmen verwendet werden. Es ist interessant festzustellen, daβ zwischen diesen beiden Kurven signifikante Unterschiede bestehen. Die biologische Kurve ist im allgemeinen in ihren Werten hölier und die induzierten Mutationsraten bei 93% einer Dosis sind signifikant höher und tiefer am Ort als jene induzierten Mutationsraten, die durch einer 100%ige Dosis physikalisch berechnet wurde. Sollte sich diese Beobachtung durch weitere dedaillierte Studien erhärten, so ist dies von groβer Bedeutung für Radiotherapeuten, die Isodosenkurven nach biologischen Bestimmungen zu planen haben.