This paper addresses the effect and influence of wave optical aberrations and surface roughness on the chromatic confocal signal and resulting measurement errors. Two possible approaches exist for implementing chromatic confocal imaging based on either refraction or diffraction. Both concepts are compared and an expression for the expected chromatic longitudinal aberrations when using a diffractive optical element is derived. Since most chromatic confocal sensors are point sensors, the discussion on wave-optical aberrations is focused on spherical aberrations. Against common belief, the effect of spherical aberrations cannot be eliminated in the calibration process using for instance a piezo mounted mirror. It will be shown in the following that even a diffraction limited system with peak to valley spherical aberration smaller than 0.25 wavelength suffers from measurement errors. Experimental results will be shown to highlight this important issue. In order to develop a deeper u...

中文翻译：

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基于实验和波光学建模的像差和粗糙度对彩色共聚焦信号的影响

本文讨论了波光学像差和表面粗糙度对彩色共聚焦信号以及由此产生的测量误差的影响和影响。存在两种可能的方法，用于基于折射或衍射来实现彩色共焦成像。对这两个概念进行了比较，并得出了使用衍射光学元件时预期的纵向色差的表达式。由于大多数彩色共焦传感器是点传感器，因此关于波光像差的讨论集中在球差上。与通常的看法相反，在使用例如压电安装镜的校准过程中无法消除球差的影响。在下面将显示，即使是峰顶球差小于0的衍射受限系统。25个波长存在测量误差。实验结果将显示出这一重要问题。为了发展更深层次的...