菲涅耳透镜

It is demonstrated by theoretical analysis and computer calculation that the focus of Fresnel zone lens will change discretely as the depth of phase changes with integral times of 2?.

理论和模拟计算表明，当环带深度改变2p 的整数倍时，菲涅耳波带透镜的焦点将发生离散的变化。

Staring from Fresnel diffraction integral,we deduced the optical intensity distribution in the Fresnel zone of the diffraction field of the annular-aperture lens axicon.

从菲涅耳衍射积分公式出发，推导多色高斯光束被球差透镜衍射后光强分布的解析公式，进行数值模拟和物理分析。

In solid immersion lens microscopy systems with high numerical aperture, there always exists the aberration produced by Fresnel effects at the interface between SIL and the sample.

在高数值孔径的固体浸没透镜显微系统中，固体浸没透镜界面与样品之间的菲涅耳效应将产生象差，这一象差可能导致样品成像质量的下降。

In consideration of the lens as a phase modulator,the integral diffraction equation of the FZP was solved digitally.

对波带板的菲涅耳衍射积分方程进行了数值求解，计算时考虑了透镜的位相调制作用。

The Focusing property of flat-topped multi-Gaussian laser beam by lens with spherical aberration is discussed.

利用广义惠更斯-菲涅耳衍射积分公式，研究了平顶多高斯光束通过球差透镜的聚焦特性。

The main contents are as follows:(1) Based on Fresnel transformation and its fast algorithm by FFT, the principle of numerical reconstruction of digital lensless Fourier transform hologram and the spatial resolution, as well as the lateral resolution of the reconstructed images plane are elaborated.

其主要内容包括：(1)从处理衍射问题的菲涅耳变换法出发，根据菲涅耳衍射积分的快速数值解法，讨论了数字无透镜傅里叶变换全息图数值再现的相关过程和理论，以及再现像平面的空间分辨率和横向分辨率问题。

It shows that the lensless Fourier transform digital hologram can be reconstructed at any distance by Fresnel transform algorithm. For convolution algorithm,the whole reconstructed image with high resolution can be acquired in an optimal reconstruction range or a small area around it.

结果表明：利用菲涅耳变换算法对离轴无透镜傅里叶变换数字全息进行重建时，无重建距离的限制；采用卷积重建法只能在最佳再现距离附近一个非常小的范围内才能获得高分辨率再现像；而采用角谱重建法在略小于最佳再现距离及大于最佳再现距离较大范围内重建，均能获得高分辨率的再现像。

A method of the optical image encryption based on the frequency splitting domain and Fresnel domain is proposed, after the analysis of the fractional Fourier transform and Fresnel transform, by synthesizing the advantages of multi keys and lensless feature of the fractional Fourier transform and Fresnel transform in the optical image encryption system.

结合分数傅里叶变换及菲涅耳变换，在光学图像加密系统中分别具有多密钥性和无透镜性的优点，提出了基于分频域和菲涅耳域的光学图像加密方法。

Based on the theorems of holography and linear system,the numerical reconstructing methods of the off-axis lensless Fourier transform hologram by Fresnel diffraction formula and by the convolution method based on Rayleigh-Sommerfeld diffraction integral and by angular spectrum theorem are studied.

根据全息理论和线性系统理论，采用离轴无透镜傅里叶变换全息记录光路，对利用菲涅耳近似法、基于瑞利—索末菲衍射积分的卷积法以及角谱理论方法数值重建全息图进行了比较研究，并做了计算机模拟验证。

It can be inferred that the focus-variable Fresnel zone lens can be made by changing the index of refraction of material.

据此分析，通过改变透镜材料的折射率，可以制作变焦的菲涅耳波带透镜。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。