Eikonal Distribution on the Surface of an Axisymmetric Dielectric Lens and Minimization of Aberrations

On the basis of the one-parametric theory of aberrations developed in the paper, a formula is obtained that describes the eikonal distribution on the surface of an axisymmetric dielectric lens with two focuses arbitrarily located on the axis and a source displaced from the focus in an arbitrary direction. The error of the formula is of the fourth order of the source displacement. A numerical analysis of the accuracy of the obtained formula and its expansions is performed by comparing the results of the eikonal calculation and the magnitude of aberrations on the surface of an aplanatic lens with the results of the exact geometrical optics calculation. The equation of the focal curve and the condition for the minimum of astigmatism are obtained. As an example of application of the formulas found, a wide-angle aplanate-anastigmat with optimal parameters is synthesized. The scanning characteristics of a lens antenna based on the synthesized aplanat-anastigmat are analyzed in the physical optics approximation.     

Eikonal aberrations in planar double-reflector antennas

A formula describing the eikonal distribution on the main reflector of a 2D double-reflector system is derived for an arbitrary direction of the offset of the source from the focus, the second focus being at infinity. The formula takes into account four terms of the expansion of the eikonal in the powers of the offset of the source. The accuracy of the formula is analyzed by comparing the results of calculation of the eikonal in a 2D Schwarzschild system with the exact geometric-optics calculation. Formulas for the focal curve, the phase front inclination angle, and aberrations in an arbitrary double-reflector telescopic system are obtained. The formula obtained is used for the analysis and minimization of aberrations in a 2D Schwarzschild system.     

On eikonal aberrations in axisymmetric double-reflector telescopic systems

A formula describing the eikonal distribution on the surface of the main reflector of a doublereflector system of a general form is derived and its expansion in powers of the offset of the source from the focus up to the fourth-order terms is obtained. The analysis and minimization of aberrations for a doublereflector aplanatic Schwarzschild system are performed.     

Synthesis and analysis of constrained polyfocal lenses with symmetric focal curves

The problems of synthesis of bifocal, trifocal, and quadrifocal constrained lenses with symmetric focal curves are solved. The solution of the problem for the shape of the lens surface in the first case is obtained in the explicit analytical form and, in the other cases, in a parametric analytical form. Based on the numerical study of the eikonal, parameters of the lenses are optimized and the analysis of the eikonal aberrations of the optimized lenses is performed for two values of the maximum angle of view: 60° and 90°. The results of a numerical experiment for a planar constrained quadrifocal lens and a maximum angle of view of 60° are presented.     

Investigation and minimization of aberrations in two-mirror imaging system

A formula for the eikonal in the aperture of an axially symmetric two-mirror imaging system is obtained for the case when the source is arbitrarily displaced from the focus. The formula yields a result accurate to the cubed value of this displacement. The Newton method is applied to find a correction improving the formula for the eikonal. On the basis of the derived formula for the eikonal, the amplitude distribution and the distribution of inclination angles of rays reflected by the main mirror are found. The astigmatism value is estimated, and formulas for the relationship of an axially symmetric two-mirror imaging system parameters that minimizes this value are presented. As an example of application of the theory, a terahertzband scanning imaging system is optimized. The simulation is performed to demonstrate the possibility of realizing a view angle exceeding 15 degrees.     

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     

On eikonal distribution in the aperture of a two-mirror telescopic system

The derivation of the formula describing the eikonal distribution in the aperture of an axially symmetric two-mirror system with the source displaced from the focus in an arbitrary direction is presented. The secondary focus of the system is assumed to be at infinity. The formula takes into account three terms of the eikonal expansion in powers of the source displacement. The accuracy of the derived formula has been analyzed by comparing the results of the calculation of the eikonal in the aperture of a Schwarzschild two-mirror aplanatic system obtained with the use of this formula to the results of the exact geometrical-optics calculation.     

Wide-angle microwave lens for line source applications

A new "time-delay" scanner consists of a constrained wide-angle two-dimensional microwave lens with a straight front face in which lens elements connect arbitrary points on the inner and outer contours. The lens can operate at very short pulse lengths and can scan more beamwidths than any previously known device of its type. A phase analysis shows that this design has very small coma aberrations and that the lens can generate fractional degree beams. Criteria developed for selecting optimum lens parameters are given. The radiation patterns of an experimental model in which the lens elements consist of coaxial cables show the expected wide-angle characteristics. In further tests incremental scanning was obtained through the use of phase shifters in the coaxial lens elements. The design of symmetrical three-dimensional lenses is briefly discussed. A table of lens contour parameters is given for an optimum lens design with scan anglealphaof30deg.     

边缘驱动双腔可变形透镜的设计及制备

针对基于边缘驱动的可变形透镜无法进行球差像差的问题,该文提出了一种边缘驱动双腔可变形透镜结构。上腔体压电圆环32个致动器,校正除球差外的其余低阶像差,主要包括离焦、像散及慧差的校正。下腔体压电圆环1个致动器,通过与上腔致动器的相互作用,实现球差的校正。搭建了可变形透镜性能测试平台并进行了实验。实验结果表明,该可变形透镜能重构前4阶Zernike像差。     

Eikonal Aberrations in Gradient Cylindrical Lenses

Journal of Communications Technology and Electronics - Approximate formulas are derived for eikonal on the output surface of a cylindrical dielectric lens with a gradient of refractive index along...     

关于波带板的焦移

实验测定了波带板的焦移,接近与广义程函数理论。     

应用六阶波像差理论的鱼眼镜头系统设计

鱼眼镜头系统具有平面对称、超大视场、大孔径成像等特点,使得其设计十分复杂。波像差理论是研究光学系统的重要手段,由于鱼眼镜头系统具有平面对称的成像特性,赛德尔初级像差和基于轴对称光学系统发展的高阶像差理论不再适用于鱼眼镜头系统的像差分析和设计。介绍了六阶波像差理论,包括六阶本征波像差、五阶像差、衍生波像差及孔径光线二阶精度对波像差的影响,给出六阶波像差理论设计鱼眼镜头系统的流程图,应用六阶波像差理论设计鱼眼镜头前光组,由其前光组与后光组像差平衡设计了后光组。最后得到一成像质量良好的鱼眼镜头系统,该镜头的焦距为5.989 mm,视场角为180°,相对孔径为1/3.2。设计结果表明,该鱼眼镜头系统的调制传递函数（MTF）数值在空间频率为60 lp/mm时均不低于0.56,具有较好的成像质量。     

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.<>     

新型两镜折反式平场消像散望远物镜光学设计

小卫星具有研制发射成本低、适于机动战术应用等优点,但基于几十kg级的卫星平台实现米级或亚米级对地光学遥感,仍是一个具有挑战性的问题。对此提出一种新的两反射镜折反系统,由两块非球面反射镜和像方负光焦度三透镜组组成,兼具传统两反射镜系统轴对称性而结构紧凑、易于装调和三反射镜系统平场消像散的优点。首先,介绍该新型系统基本思想与结构,导出其初级像差公式,分析给出色差和单色像差校正方法与初始结构求解方法。然后,实例优化设计得到结构紧凑、适用于低轨高分辨率小卫星对地遥感的光学系统,其工作波段、全视场角、有效焦距和F数分别为450~800 nm、1.2、3000 mm和F/10,系统的光学总长和通光口径分别为595 mm和300 mm。自身消色差的负光焦度透镜组由同种普通玻璃组成,系统成像质量接近衍射极限。     

Maxwell鱼眼微球透镜对有限远物点的成像及其像差

本文在文献［１］的基础上用变折射率介质中的光线理论研究了Ｍａｘｗｅｌｌ鱼眼球透镜对有限远物点成像的可能，导出了它对有限运物点的像距和纵、横向球差的计算公式。数值计算的结果表明该种球透镜不仅可以对有限远物点成像，且其纵、横向球差甚小．若合适选取透镜的参数，其纵、横向球差可比均匀折射率球透镜小两、三个数量级，在短物距时也比自聚焦棒透镜小。从而进一步显示了它在集成光学和微型光学系统中应用的可能性。     

Efficiency of quasi-optical couplers

Millimeter-wave devices are often coupled to radiation by means of a feed antenna placed at the focus of a primary lens or mirror, a technique known as “quasioptical coupling”. A general expression for the efficiency of such a coupler is derived. The efficiency of such a coupler depends on the relationship of the feed antenna pattern to the numerical aperture of the primary lens. An approximate general rule for coupler design is obtained. This rule is as follows. Let θ_o be the angle between the direction in which the feed pattern is maximum and the direction in which the pattern intensity has one-half its maximum value. Then the optimum numerical aperture of the primary lens is approximately sin (1.67 θ_o). The effects of focussing errors and lens aberrations can also be calculated by this technique.     

面向高性能的红外折射式镜头装调技术

针对红外光学材料折射率不均匀导致系统波前产生异常像差,从而引起镜头像质严重下降的问题,提出了一种光学件位置迭代调整和面形修配相结合的系统波前补偿方法,实现面向高性能的红外折射式镜头装调。在光学件精密定心的基础上,设计了在线装调检测装置,依据镜头实测波前并结合计算机辅助装调技术,通过迭代调整光学件位置矫正系统波前初阶像差。对系统残留的中高阶像差,根据各视场测得的系统波前综合分析计算,采用修配光瞳处光学件面形,引入反残留波像差的方式补偿。实验上,通过对某红外折射式镜头装调,将镜头三个视场系统波前RMS (λ=3.39μm)分别由精密定心后的0.162λ、0.118λ、0.166λ降低至0.064λ、0.040λ、0.067λ,平均MTF (@25 lp/mm)由0.31提升至0.67。结果表明,这种装调技术对红外折射式镜头系统波前补偿效果明显,可大幅提升镜头成像性能,具有重要的工程应用价值。     

Measurement of wave-front aberrations in high-resolution opticallithographic systems from printed photoresist patterns

A new method of measurement of wave-front aberrations in high-resolution optical lithographic systems used for semiconductor manufacturing is proposed. The method is based on the measurement of the positional shifts and focus offsets of a set of printed photoresist grating patterns with different periods and orientations, produced under nearly fully coherent illumination condition. The proposed experimental procedures are described in detail and various sources of systematic and random errors are discussed. It is estimated that a measurement precision of λ/50 for the wave-front aberrations at selected points on the lens pupil can be achieved with this method     

应用于环形激光束的低阶哈特曼波前传感器设计

针对高能化学激光器出光过程中存在着大比例、大PV值低阶像差这一现象,设计了专用于前5项Zernike像差检测的低阶哈特曼波前传感器。该传感器的透镜部分采用呈环形分布的6单元微透镜阵列与凸透镜组合的方法,且均用CaF₂材料制作。该方法不仅可以同时用于可见光和红外光的低阶像差测量,还具有成本低、光路结构简单、探测范围大等优点,适用于环形激光束的大PV值低阶像差检测。之后还搭建了测试光路系统,测试结果表明,该低阶哈特曼波前传感器的波面测量PV值量程为±8λ （λ=3.39 μm）,测量精度优于λ/10 （λ=3.39 μm）。     

光刻机投影物镜像差的现场测量技术

为了在光刻机工作过程中保证投影物镜的成像质量．人们开发了一系列投影物镜像差的现场测量技术。对目前国际上常用的几种高精度投影物镜像差现场测量技术进行了分析和比较。