对Talbot白成像和几何成像关系的分析

针对Talbot自成像与几何光学成像毫无关系的传统观点,本文提出了一种用于几何光学成像原理和物理光学成像原理对光栅成像进行对比分析的方法,发现在某一特殊的Talbot成像距离处,光栅自成像和几何成像有相同的成像规律,当光源为单色光照射时可以认为光栅的几何成像实际上是某一个特殊位置的Talbot像．     

空-频域中自成像分析和解释

基于魏格纳变换和魏格纳分布函数,分析讨论一维物体在空域-频域空间的自成像及其形成过程。从成像过程中各衍射频谱分量的光程差出发,给出Talbot效应和Montgomery效应的统一解释。对于周期物的Talbot效应,得到了用杨氏双缝干涉解释自成像现象的理论依据。周期物的自成像是物平面上间距为2倍周期,光程差为波长的整数平方倍的各衍射频谱分量同相相干迭加的结果。Montgomery效应是物平面上间距为抛物线关系,光程差为波长整数倍的各衍射频谱分量同相相干迭加的结果。     

自成像魏格纳函数分析

在空域-频域空间,基于魏格纳变换和魏格纳分布函数,分析讨论了一维物体的自成像及其形成过程.从成像过程中各衍射频谱分量的光程差,给出了Talbot效应和Montgomery效应的统一解释.对于周期物的Talbot效应,得到了用杨氏双缝干涉解释自成像现象的理论依据.周期物的自成像是物平面上间距为两倍周期、光程差为波长的整数平方倍的各衍射频谱分量同相相干迭加的结果.Montgomery效应是物平面上间距为抛物线关系、光程差为波长整数倍的各衍射频谱分量同相相干迭加的结果.     

一种光学成像垂轴几何畸变校正方法

光学成像系统非线性几何畸变的校正仍是一个未能很好解决的课题，一些方法还不能很好地实用。本文对成像系统主要因镜头的失常导致的非线性几何畸变，分析了成像过程。提出一种以径向几何畸变为主的非线性几何畸变模型。依据此模型，提出一种通用的校正方法，应用计算机处理，可对实际的非线性几何畸变图像进行校正。文中用所提出的方法对实际成像的畸变进行了校正，给出了校正实验结果，校正效果良好，有一定的实验价值。     

提高广角成像系统几何畸变数字校正精度的方法

光学成像系统非线性几何畸变的高精度数字校正仍然是一个未能很好解决的问题。其中 ,衡量畸变程度的参数难以精确测量是最重要的原因之一。在以径向几何畸变为主的非线性几何畸变模型中 ,通过对影响畸变参数测量精度的各种因素的分析 ,提出了提高畸变参数测量精度的方法。详细介绍了通过计算机自动测量畸变参数的算法 ,并给出了实现数字校正的算法。实验表明 ,能够比较精确地测出实现畸变校正所需的各参数。应用到不规则平面物体面积的测量中 ,获得了很好的效果     

高斯光束照射下的近似Talbot自成像效应及其两种新应用

本文讨论了高斯光束照明下的Talbot近似自成像的性质.提出了利用Talbot自成像测量高斯光束发散角的简便方法;也提出在满足一定条件下,可得到自成像的超高倍放大率.     

一个研究型物理实验项目——周期物成像规律实验

介绍清华大学物理系如何将“Talbot效应实验”排成研究型实验,以利激发学生的求知欲,拓宽知识面,进而促进其综合能力提高的有益经验。     

薄透镜反射成像研究

从薄透镜反射成像的实验现象出发，运用光学系统中变换矩阵的有关理论，研究了薄透镜的反射成像规律，并对双凸透镜及平凸透镜的反射成像进行了定量分析。     

Gain Assisted Raman Induced Classical and Quantum Talbot Imaging

2D Raman generated classical and quantum Talbot imaging is proposed in a three-level gain assisted system. First, a 2D Raman induced grating (RIG) will be constructed by modulating transmission function in the weak probe channel using a strong control standing wave field. Furthermore, RIG will diffract a probe field, by shining a probing light beam on an optically generated lattice within a rubidium vapor cell. This study uses gain assisted Raman medium [Nature 406 , 277 (2000)] to examine classical and quantum Talbot imaging. In the case of Raman-induced classical imaging, the diffraction pattern repeats itself at planes with integer multiple Talbot lengths. Additionally, by taking into account entangled photon pairs, the scenario of Raman-induced quantum imaging is investigated. This study also looks at the RIG's amplitude and phase information with adjustable image size variation. As a result of the gain feature and zero absorption, this system is anticipated to be more suitable from the perspective of application. This analysis may pave the way for further research into the Talbot effect's nonlinear and quantum dynamical properties. Also, it provide a non-destructive, lensless method for imaging very cold atoms or molecules.     

Texture Image Segmentation Using Talbot Effect

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Efficiency Enhancement of Components Based on Talbot Effect

Two ways to improve efficiency of components based on Talbot effect are considered in the present paper. One way is based on optimization of waveguide wall impedance, another one consists in modification of waveguide cross-section shape. Both methods allow correction of waveguide modes spectrum and lead to efficiency enhancement. For the important application of Talbot effect-remote steering antenna of a wavebeam in plasma-the steering band is expanded by 40–50%.     

用Talbot效应检验激光准直性

提出了一种激光准直性的判断方法。通过一块光栅和DⅡ?180°直角棱镜,使光栅产生的 Talbot 像与光栅自身产生 Moire 条纹,通过判断 Moire 条纹的取向来检验激光的准直性。     

Refractive power mapping of progressive power lenses using Talbot interferometry and digital image processing

A method of refractive power mapping of a lens is presented which is based on Talbot interferometry and utilizes a digital image processor. By adding a digital image processing system, fast measurement of a lens power distribution is feasible. A test lens is placed in front of two collinearly arranged gratings. The light passing through the test lens produces a shifted Talbot image of the first grating on the second grating and generates moiré fringes. Given the inclination angle of moiré fringes, the refractive power of the lens can be calculated. The calculation is performed using a digital image processor. This method is effective in finding the refractive power distribution of progressive power lenses.     

分析光栅分数塔尔博特效应的一组新方程

对一维开口比为1/M(这里M为大于1的正整数)的短形光栅,建立了一组新 在分数塔尔博特(Talbot)距离上计算其菲涅 法射光场分布的简单方程.在该方程中考虑了光栅结构与分数塔尔博特距离的联系,显然比迭代方程和基于距离的方程更方便地描述分数塔尔博特效应.给出了一种研究光栅分数塔尔博特铲应的新途径.     

Optical Texture Super-Lattices Produced by Talbot Effect at Superimposed Gratings

Fresnel diffraction on periodic gratings results in a two-dimensional periodic distribution of light intensity, also known as the Talbot effect. Here this approach is extended to the family of superimposed structures with translational symmetry, which consist of superposed spatial harmonics. The Talbot effect is demonstrated to be valid for superimposed gratings. The considered superimposed gratings provide a wide range of textures of optical super-lattices. These texture super-lattices represent a Talbot carpets with a complex motif, which can be varied by choosing structure parameters. These results provide a new functionality for structuring optical lattices and can find potential applications in a wide range of light–matter interactions.     

利用杨氏双缝干涉讨论Talbot效应

利用杨氏双缝干涉原理讨论了平行光垂直照射下光栅的Tablot及分数Tablot现象.在成像平面上所观察到的光栅衍射条纹实质上是光栅中一定缝距的许多双缝对的杨氏干涉条纹的可除相干叠加条纹,其条纹间距和明暗中心位置都未变化;但是像相对于光栅即条纹分布相对于光栅刻线可能有半个周期的偏移,这可由双缝对参数α的奇偶决定,如果α为偶数则没有偏移,如果α为奇数则有偏移.     

Optimization of a Frequency Diplexer Based on the Talbot Effect in Oversized Rectangular Waveguides

Calculations of a rectangular waveguide frequency diplexer for high power applications based on the Talbot effect are presented. For the calculation, a method based on analytical approximations, which is valid in highly oversized waveguides, as well as a more accurate mode analysis method are described. The latter allows the integration into an optimization code, which reduces mode conversion losses while maintaining practicable geometrical dimensions.