Idir Mourad, Cywiak Moisés, Morales Arquímedes, Modi Mohammed H
Brookhaven National Laboratory – NSLS II 50 Rutherford Dr. Upton, New York 11973-5000, USA.
Opt Express. 2011 Sep 26;19(20):19050-60. doi: 10.1364/OE.19.019050.
We present an efficient method to perform x-ray optics simulation with high or partially coherent x-ray sources using Gaussian superposition technique. In a previous paper, we have demonstrated that full characterization of optical systems, diffractive and geometric, is possible by using the Fresnel Gaussian Shape Invariant (FGSI) previously reported in the literature. The complex amplitude distribution in the object plane is represented by a linear superposition of complex Gaussians wavelets and then propagated through the optical system by means of the referred Gaussian invariant. This allows ray tracing through the optical system and at the same time allows calculating with high precision the complex wave-amplitude distribution at any plane of observation. This technique can be applied in a wide spectral range where the Fresnel diffraction integral applies including visible, x-rays, acoustic waves, etc. We describe the technique and include some computer simulations as illustrative examples for x-ray optical component. We show also that this method can be used to study partial or total coherence illumination problem.
我们提出了一种利用高斯叠加技术对高相干或部分相干X射线源进行X射线光学模拟的有效方法。在之前的一篇论文中，我们已经证明，通过使用文献中先前报道的菲涅耳高斯形状不变量（FGSI），可以对光学系统（包括衍射和几何光学系统）进行全面表征。物平面中的复振幅分布由复高斯小波的线性叠加表示，然后借助所述高斯不变量在光学系统中传播。这既允许通过光学系统进行光线追踪，同时又能高精度地计算任意观察平面处的复波振幅分布。该技术可应用于菲涅耳衍射积分适用的广泛光谱范围，包括可见光、X射线、声波等。我们描述了该技术，并给出了一些计算机模拟作为X射线光学元件的示例。我们还表明，该方法可用于研究部分或完全相干照明问题。
