本文从部份相干理论出发,导出了随机孔屏的衍射强度期望分布及涨落方差表达式;对随机孔屏的衍射特性作了较深入的分析;讨论了光源的空间特性对衍射图形的影响;研究表明:衍射强度的光场分布不仅与孔和屏的几何特性有关,还与光源的形状和大小密切相关.文中还指出:在特定照明情况下,形状一定的小孔无论在数目还是尺寸上发生随机变化,都不会改变衍射场的强度期望分布和涨落方差分布.

Based on the partial coherence theory, this paper derives the formula of intensity and variance of diffraction from a screen with randomly- distributed holes. The diffraction characteristics of the screen are analysed in detail, and the effect of spatial characteristics of the source on diffractive image is discussed. It has been shown that the light intensity distribution of diffraction field depends on geometric characteristics of the holes and the screen, and shape and size of the light source as well. This paper also shows that under certain illumination, both average intensity and variance distributions in diffraction field will not change if the number or size of definitely-shaped holes in the screen randomly changes.