狭缝和矩形光阑对频谱的影响

The Effect of Rectangular and Slit Aperture on the Spectrum of Partially Coherent Light

本文研究了不相干光源通过傅里叶变换系统后产生的二次光源，通过矩形和狭缝光阑后的频谱变化，产生的频移取决于光阑与光源空间相干长度的比，且与圆形光阑产生的频移作了比较，两者有一定差异。

It is shown for a Second source field that, when such a field is incident upon a reclangular or a slit aperture, the spectrum of the light at an observation point in the far zone of the aperture is different from the spectrum of the ligt in the aperture. An explicit expression for the spectrum at such observation points is obtained, and it is shown that the difference between the two spectra depends on the ratio of the size of the aperture to the offective corelation length of the light in the apertuer. Numerical examples are presented. There are some difference comparing to the results of circular aperture.