Torcal-Milla Francisco Jose, Sanchez-Brea Luis Miguel
Optics Department, Applied Optics Complutense Group, Universidad Complutense de Madrid Facultad de Ciencias Físicas, Ciudad Universitarias.n., 28040, Madrid, Spain.
J Opt Soc Am A Opt Image Sci Vis. 2011 Mar 1;28(3):308-13. doi: 10.1364/JOSAA.28.000308.
In this work we analyze the near-field intensity distribution produced by a rough grating illuminated with a Gaussian-Schell-model beam. This kind of grating is formed by rough and smooth slits. Statistical techniques are used to describe the grating, and the Fresnel approach is used to perform the propagation of light. Two kinds of coherence affect the light propagation. One of them comes from the light beam, since it is not totally coherent. The other one comes from the rough topography of the grating surface. We have found that the Talbot effect is not present just after the grating, but it gradually increases. In addition, the contrast of the self-images decreases from a certain distance due to the coherence properties of the illumination beam. Then, the self-imaging process is only present between two specific distances from the grating. To corroborate the analytical results, we have performed numerical simulations for the mean intensity distribution based on the Sommerfeld-Rayleigh approach, showing their validity.
在这项工作中，我们分析了由高斯-谢尔模型光束照射的粗糙光栅产生的近场强度分布。这种光栅由粗糙和光滑的狭缝组成。采用统计技术来描述光栅，并使用菲涅耳方法进行光的传播。两种相干性影响光的传播。其中一种来自光束，因为它并非完全相干。另一种来自光栅表面的粗糙形貌。我们发现，在光栅之后并不会立即出现塔尔博特效应，而是会逐渐增强。此外，由于照明光束的相干特性，自成像的对比度从一定距离开始降低。然后，自成像过程仅出现在距离光栅的两个特定距离之间。为了证实分析结果，我们基于索末菲-瑞利方法对平均强度分布进行了数值模拟，证明了其有效性。
