Bradley aberration proposed to measure absolute velocity of closed laboratory

Bradley aberration, which uses the yearly angular displacement of starlight to measure the velocity of the Earth about the sun, can be used in the closed laboratory to measure the absolute velocity of the laboratory. Lasers replace starlight. Comparing the aberration for two oppositely directed light beams as a function of direction, the absolute velocity of the laboratory may be deduced. A special telescope to be used to detect small angular changes is described.     

Proposal to measure terrestrial Bradley aberration

Because parallax exactly masks Bradley aberration when ordinary terrestrial sources are used; it is proposed to measure the angle of parallax, and thus, the angle of aberration, by observing telescopically the appearance of a three dimensional object used as a source. For a setup rigidly fixed to the Earth's surface at a northern latitude the variation of the appearance of the object as a function of the time of day can then yield the magnitude and direction of the absolute velocity of the Earth.     

模拟合成孔径雷达数据片波差的测量和胶片、波差的容限

本文介绍一种用马赫-陈德干涉系统测量模拟合成孔径雷达数据片波差的方法.该法能把两种原因产生的波差区分开来,即把通过胶片变形的波面与平面参考波面比较,求出胶片厚度不平产生的波差;把合成孔径雷达数据片的一级衍射波面与两个半径不等的参考球面波比较,分别求出由模拟装置产生的方位维和斜距维波差.本文给出一些实验结果和分析.这种方法还可以用于测量真实合成孔径雷达数据片的波差.由胶片厚度变化产生的波差可以用液体门补偿.但是,在实际中使用液体门是很繁复的,有时也没有必要.因此,我们认瑞利准则出发导出合成孔径雷达数据片胶片厚度变化产生的波差的容限,以此作为判断是否要用液体门的依据.     

基于整形光路的低阶像差校正方法

为满足激光束对远处目标辐照强度的要求,减小热效应对输出光束性能的影响,提出了一种基于整形光路的高能激光低阶像差校正方法。该方法根据波前探测器测到的光束波前畸变,利用激光器整形光路固有的光学元件和调整机构,通过高精密电动平移台和快反镜的快速动作,动态调整各镜片的间距,实时校正激光束的低阶像差,使输出光束恢复至平行出射,从而显著减小激光束的热漂移和热畸变,有效避免了长时间出光时光束的持续发散,极大改善了输出光束性能。试验结果表明,该方法具有校正量大、控制方便、结构紧凑等优点,能够很好地改善激光器输出光束质量,显著提高激光束远场作用效果。     

自聚焦透镜列阵的色差测量

本文分析了色差的产生和表示，计算和测量了锂玻璃自聚焦透镜成像系统中的轴向色差与横向色差，讨论了色差对自聚焦透镜列阵成像的影响。     

采用色差先验约束的像差校正技术

本文通过分析自然图像的边缘3个通道之间的关联性,提出"同一物体的边缘在3个颜色通道应处于相同位置"的色差先验约束,该约束在数学上近似为各通道的相对导数相等,基于此色差先验约束,建立了一种新的像差校正模型即图像解卷积模型,并给出了基于交替方向乘子法的模型求解算法。实验结果表明:本文的像差校正技术可以提升图像的峰值信噪比10 dB以上,明显优于目前主流的BM3D和YUV算法,并且视觉提升效果明显,基本满足普通光学系统对像差的校正要求。     

Considering the effectiveness of 3rd order aberration theory from the view point of sine condition in the presence of spherical aberration

Even though the level of computer simulation for optical designing is becoming powerful, the 3rd order aberration theory is still useful for prospecting optical characteristics and developing optics. Therefore, it is important to confirm its validity even now. Considering the physical meaning of imaging, pupil coordinates should be defined by the direction cosine of the ray. The sine condition in the presence of spherical aberration has been derived by using this coordinate and its validity was later confirmed by practical lens designing. On the other hand, in order to deal with object imaging and pupil imaging equivalently, conventional aberration theory uses the pupil coordinate defined by the slope of the ray. By applying this theory, it had been deduced that no spherical aberration exists when the isoplanatic condition is fulfilled and it was then concluded that the sine condition in the presence of spherical aberration is meaningless. Therefore, one might think that this conventional aberration theory is less useful. However, this time I found that the 3rd order spherical aberration can exist with no 3rd order coma aberration under this aberration theory. As a result, the conventional aberration theory is meaningful at least in the 3rd order region.     

界面反射偏振像差分析

对轴外点发出的一束光线经界面反射形成的偏振像差进行了研究,并对两种具体情况进行了讨论.     

Naked singularities cannot be observed (An information-theoretic approach to the cosmic censorship conjecture)

In this article we review some recent results obtained in the interplay between field theory in curved space-time and information theory, and explore some consequences. We shall explain how the Weyl tensor becomes responsible for the creation of quantum noise which, in turn, degrades a considerable fraction of the information which is optically transferred in a curved space-time. We conclude that causal connection between spacetime regions, although being a necessary condition for transmitting information between them, is by no means sufficient. This is because this quantum noise might preclude the observation of very distant objects in the Universe and even closer ones if it becomes very intense. We argue that naked singularities are very powerful sources of noise and, therefore, cannot be observed optically. This leads to the intriguing possibility that the no-hair theorem might be more general than was thought before.     

特殊整流罩窗口的非对称像差研究

分析了居中球形整流罩的波像差和偏心球形整流罩的波像差。为了分析共形整流罩的一般像差特性,建立了不同类型的整流罩模型,重点分析了像散和彗差,讨论了一阶和五阶像差,并与球形整流罩和偏心球形整流罩的相应像差做了比较。分析了长宽比、边缘厚度与顶点厚度比对像差的影响。     

Spherical aberration and its correction using Lie algebraic methods

We discuss three methods to correct spherical aberration for a point to point imaging system. First, results obtained using Fermat’s principle and the ray tracing method are described briefly. Next, we obtain solutions using Lie algebraic techniques. Even though one cannot always obtain analytical results using this method, it is often more powerful than the first method. The result obtained with this approach is compared and found to agree with the exact result of the first method.     

Zernike模式像差共轭组合模型

根据Zernike模式在单位圆的同心孔径圆域内某些模式间具有一定耦合性的结论及对应Zernike模式像差在一定同心光瞳区域内的相互抵消特性,对具有相同角频率不同阶数的Zernike模式建立组合模型,同时根据同心光瞳区域内像差均方根值的降幅比参数给出了同心光瞳直径为4mm时的Zernike模式线性共轭组合模型。最后通过共轭组合模型对光学质量影响的研究发现,共轭模型组合之后能显著提高光学质量。同时也表明Zernike模式组合对光学质量的影响不具备叠加性,而对共轭组合模型表现为补偿关系。     

Sphere-cone-polynomial special window with good aberration characteristic

Optical windows with external surfaces shaped to satisfy operational environment needs are known as special windows. A novel special window, a sphere-cone-polynomial (SCP) window, is proposed. The formulas of this window shape are given. An SCP MgF2 window with a fineness ratio of 1.33 is designed as an example. The field-of-regard (FOR) angle is ±75°. From the window system simulation results obtained with the calculated fluid dynamics (CFD) and optical design software, we find that compared to the conventional window forms, the SCP shape can not only introduce relatively less drag in the airflow, but also have the minimal effect on imaging. So the SCP window optical system can achieve a high image quality across a super wide FOR without adding extra aberration correctors. The tolerance analysis results show that the optical performance can be maintained with a reasonable fabricating tolerance to manufacturing errors.     

Effect of chromatic aberration on Gaussian beams: non-dispersive laser resonators

The propagation of a non-monochromatic (polychromatic) TEM₀₀ Gaussian beam in vacuum, its passage through a thin plate and its transformation by a thin lens are studied in the case of a non-dispersive laser resonator. The basic assumptions of the model are as follows: optical fields are stationary and plane-polarized, the paraxial wave equation is valid, an equivalent non-dispersive hemiconfocal resonator represents the lasing medium and its stable resonator, the laser emits in a single mode. It is also assumed that the plate and the lens have large transverse dimensions. Mathematical expressions, for beam radius, divergence, radius of curvature and beam parameter product, are obtained. A beam quality factor for polychromatic Gaussian beams is defined and its value calculated in each case of interest. It is proposed to simulate a dispersive laser resonator by a non-dispersive resonator complemented with a plate and/or a thin lens.     

光学系统的偏振像差研究

综合论述了偏振像差的理论,给出了具体的例子,指出偏振是影响光学系统性能的一个重要因素,要想提高光学系统的性能,必须控制光学系统的偏振像差,而且光学系统设计必须与光学薄膜的设计结合起来。     

减小球差的环带透镜设计

根据光线经过折射面后像距和折射面参数之间的关系,将折射面划分为若干同心圆环,各圆环之间沿光轴有一定的轴向间隔。一束平行于光轴的光线入射后,经过不同部分光线的像点相互重叠从而使球差减小。根据上述思想用单透镜构造一个透镜称为环带透镜,然后以环数为2的透镜为例用CODE V进行像差分析。和双胶合透镜比较得出:环带透镜的球差、波像差以及轴上点的弥散斑优于胶合透镜,同时光学传递函数指标提高,接近衍射极限。     

应用折-衍射元件校正人眼色差

提出了采用两个折射-衍射元件对人眼系统在14°范围内进行色差校正的光学系统设计方法。基于系统光学性能的评价与单片折射-衍射元件色差校正系统的对比验证了本文提出的色差校正系统的性能。结果表明：两种色差校正系统都可以很好地校正人眼的轴向色差。但是,单片折射一衍射色差校正系统引入了横向色差,其由校正前的14．51μm增加到81．4μm,严重影响了边缘视场处的成像质量。而采用双片折射一衍射元件的色差校正系统可同时对轴向色差和横向色差进行校正,使横向色差降为1．64μm。设计的色差校正系统可有效提高视网膜的成像质量,并可用于视觉仪器。     

梯度折射率棒透镜的色差估计

对梯度折射率(GRIN)棒透镜色差的影响因素进行了研究,在玻璃光学性质计算模型的基础上建立了梯度折射率棒透镜色差估计函数与基础玻璃性能、交换离子对性质和参与交换的离子数量之间的关系。对Na+/Li+,K+/Cs+和K+/Tl+交换制备的梯度折射率棒透镜的色差进行了计算,结果表明,GRIN棒透镜的色差评价函数主要取决于基础玻璃和交换离子的性质,而与参与交换的离子数量无关。     

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。