艾里斑

艾里斑随圆孔直径的变化3D图

艾里斑随圆孔直径的变化2D图

艾里斑是点光源通过理想透镜成像时，由于繞射而在焦点处形成的光斑。中央是明亮的圆斑，周围有一组较弱的明暗相间的同心环状条纹，把其中以第一暗环为界限的中央亮斑称作艾里斑。这个光斑的大小可以用下面的公式来估计：

$\sin \theta \approx 1.22\frac{\lambda }{d}$

艾里斑是以英国皇家天文学家乔治·比德尔·艾里的名字命名的。因为他在1835年的论文中第一次给出了这个现象的理论解释。

外部链接

• "Concepts and Formulas in Microscopy: Resolution" Template:Wayback by Michael W. Davidson, Nikon MicroscopyU (website).
• "Image Formation: Numerical Aperture and Image Resolution" Template:Wayback (Interactive Java Tutorial) by Kenneth R. Spring, Brian O. Flynn, and Michael W. Davidson, Molecular Expressions (website), June 15, 2006.
• "Image Formation: Airy Pattern Formation" Template:Wayback (Interactive Java Tutorial) by Kenneth R. Spring, Brian O. Flynn, and Michael W. Davidson, Molecular Expressions (website), June 15, 2006.
• "Diffraction from a Circular Aperture" Template:Wayback by Paul Padley, Connexions (website), November 8, 2005. – Mathematical details to derive the above formula.
• "The Airy Disk: An Explanation Of What It Is, And Why You Can’t Avoid It", Oldham Optical UK.