当前位置: X-MOL 学术Optoelectron. Instrument. Proc. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Calculating the Images of a Volume Asymmetric Ideally Absorbing Edge of an Object in Coherent Light
Optoelectronics, Instrumentation and Data Processing Pub Date : 2021-04-02 , DOI: 10.3103/s8756699020060060
Yu. V. Chugui

Abstract

The peculiarities of image formation of a volume asymmetric ideally absorbing edge, the main fragment of extended (in depth) plates of constant thickness, in diffraction limited projection system are analytically studied with application to the size inspection of 3D objects. The structures and profiles of intensities in the images of the front and rear faces of object are investigated at small and large apertures of the optical system for different relations between the object bevel \(c\), the size of the Fresnel zone \(\delta_{d}\sim\sqrt{\lambda d}\) (\(\lambda\) is the wavelength of light and \(d\) is the object thickness), and angular aperture of the optical system \(2\theta_{0}\). In the case when the bevel \(c\ll\delta_{d}\), at large focal depth of the system the intensity profile is displaced in the image of the 3D edge in linear proportion to the Fresnel zone and to the bevel size. It is analytically demonstrated that, for large bevels (\(c\gg\delta_{d}\)) and small apertures of the system in the plane conjugating with the front face, a sharp image of either the front face (the rear face is shadowed) or the rear face (the front face is shadowed by the rear face) is observed. The formulas for the image profile of the rear face are obtained and studied in the case of significant volume effects, when the focal depth of the system is far smaller than the object thickness. The calculation results are in good agreement with the results of computer modeling.



中文翻译:

计算相干光中物体的体积非对称理想吸收边缘的图像

摘要

在衍射受限的投影系统中,对体积不对称的理想吸收边缘(恒定厚度的扩展(深度)板的主要片段)在衍射受限投影系统中成像的特殊性进行了分析研究,并将其应用于3D对象的尺寸检查。针对物体斜面\(c \),菲涅耳区大小\(\ delta_ {d} \ sim \ sqrt {\ lambda d} \)\(\ lambda \)是光的波长,\(d \)是物体的厚度),以及光学系统的角孔径\(2 \ theta_ {0} \)。在斜角\(c \ ll \ delta_ {d} \)的情况下,在系统的较大焦深下,强度分布在3D边缘图像中的位移与菲涅耳区域和斜角大小成线性比例。通过分析证明,对于大斜角(\(c \ gg \ delta_ {d} \))和系统中与正面共轭的平面中的小孔径,任一正面(背面)的清晰图像阴影)或观察到背面(正面被背面阴影)。当系统的焦深远小于物体厚度时,在明显的体积效应的情况下,可以获得并研究了背面图像轮廓的公式。计算结果与计算机建模结果吻合良好。

更新日期:2021-04-06
down
wechat
bug