径向双折射滤波器的超分辨性能研究

超分辨技术因其可以超越经典的衍射极限而为人们所熟知．并且．在光存储和共焦扫描成像系统中有着广泛的应用。把由两个偏振器和一个圆对称的双折射元件组成的径向双折射滤波器引入超分辨技术，借助琼斯算法推导出其光瞳函数的表达式。由分析得出通过改变径向双折射滤波器中偏振器的偏振方向和双折射元件的主轴之间的夹角，即可实现光学系统的横向超分辨或轴向超分辨。同时对评价该器件超分辨性能的参量第一零点比、斯特尔比和旁瓣强度抑制比做了详细的讨论。该滤波器用于超分辨技术的优点在于其制作不涉及相位的变化而比较简单，且费用比较低。缺点是

孔径光阑限制下高斯光束的传输

对高斯光束在硬边孔径限制下的衍射进行了详细的理论研究，就不同口径的圆孔限制下高斯光束在菲涅耳衍射区和夫琅禾费衍射区的分布进行了理论分析，从而得到了孔径受限高斯光束的横向以及轴向的衍射公式，进而对高斯光束在不同衍射区域内衍射光场分布形状随孔径尺寸变化时的演化规律进行了数值计算，并对小口径光阑受限的高斯光束的衍射与平行光经同尺寸光阑的衍射进行了比较。结果表明在较小口径下，两者的分布基本一致。得到的孔径光阑限制下高斯光束的传输规律为高斯光束在自由空间光通信和光学超分辨中的应用提供了理论基础。

Phase-space analysis of wavefront coding imaging systems

We explore the use of the Radon-Wigner transform, which is associated with the fractional Fourier transform of the pupil function, for determining the point spread function (PSF) of an incoherant defocused optical system. Then we introduce these phase-space tools to analyse the wavefront coding imaging system. It is shown that the shape of the PSF for such a system is highly invarient to the defocous-related aberrations except for a lateral shift. The optical transfer function of this system is also investigated briefly from a new understanding of ambiguity function.

Superresolution, extended focal depth or focal shift with electrically controllable radial birefringent filter

In this paper an electrically controllable radial birefringent pupil filter is proposed. It consists of two polarizers and an improved electrically controllable optical azimuth rotator which has two lambda/4 retarders, one electro-optical crystal and one radial birefringent crystal. The evolution and distribution of polarization states of this pupil filter are discussed. The most interesting and useful advantage of such a structure is that the characteristic of transverse superresolution and axial extended focal depth or focal shift can be obtained merely by controlling the applied voltage on the electro-optical crystal. The radial birefringent crystal azimuth angle cooperating with different electrical inductive phase differences will determine the transverse and axial intensity distribution. It is shown that for particular ranges of electrical inductive phase difference it is possible to obtain transverse superresolution along with extended focal depth or with a focal shift.

照明光瞳非对称性对光刻成像质量的影响

研究了照明光瞳非对称性对光刻成像质量的影响。通过PROLITH软件计算了环形与四极照明条件下，光瞳非对称性对图形位置偏移量、曝光图形内水平线条与垂直线条的宽度差、曝光图形上密集线条与孤立线条之间线宽偏差的影响。研究结果表明，光瞳非对称性主要影响曝光图形的位置偏移量，光瞳非对称性引起的图形位置偏移量与光瞳非对称性的大小成线性关系。根据套刻精度的误差分配原则，计算得到光瞳非对称性的容限为5％。

复振幅光瞳滤波器的三维超分辨性能研究

超分辨技术中现有的纯振幅型或纯相位型光瞳滤波器，大部分只能实现轴向或横向超分辨而不能实现三维超分辨，三维超分辨在三维成像系统中有着重要的作用。因此为提高成像系统中的三维分辨能力，设计了一种复振幅光瞳滤波器，并对其三维超分辨性能进行了研究。详细分析了该光瞳滤波器的第一区半径和透射率对施特雷尔比、轴向和横向超分辨因子以及旁瓣能量的影响。通过一系列的模拟证明，借助于复振幅光瞳滤波器可以实现三维超分辨。该滤波器的优点是容易实现三维超分辨，且有比较高的施特雷尔比，缺点是三维超分辨的实现总是伴随着旁瓣能量的增加，但可

Digital holographic aberration compensation in electron holography

This paper proposes a new digital method to compensate for the aberration of an electron objective lens in electron holography. In this method, the object wavefront in the exit pupil plane is numerically reconstructed from a digitized electron hologram, and is corrected by multiplying it with the conjugated phase-error function. Then, an aberration-free image can be obtained by calculating the Fresnel integral of this corrected wavefront. In comparison with traditional methods, this method is much more convenient and accurate. Some verifying experiments are also presented in this paper. (C) 2003 Society of Photo-optical Instrumentation Engineers.

阿片类药物成瘾者瞳孔光反射的检测和特征提取

建立了一种基于图像处理的快速瞳孔直径检测算法,运用此算法提取了反映阿片类药物成瘾人员与正常人对瞳孔光反射变化差异的3个特征值:绝对收缩幅度(absolute amplitude of contraction,AAC)、相对收缩幅度(relative amplitude of contraction,RAC)和收缩斜率(SCV,slope of contraction velocity);分别研究了成瘾、性别、近视、年龄、睡眠剥夺等因素对于这3个特征值的影响。不同性别、近视人员、睡眠剥夺人员与正常人之间的3个特征值均无显著差异,成瘾人员与之对比均显著减小。老年人相对于正常青年人,3个特征值都明显减小;与成瘾人员相比,仅在RAC值上有显著差异。结果表明,阿片类药物成瘾人员除了与正常人外,也与其他具有潜在影响瞳孔变化因素的非阿片成瘾人员在瞳孔对光反射的特征值上具有显著差异。该研究的实验数据为进一步建立基于检测瞳孔对光反射其直径发生变化的方法来快速、非接触地鉴别出阿片类药物成瘾人员提供了可靠的依据。