Wen Han, Kemble Camille K, Bennett Eric E
National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Opt Express. 2011 Dec 5;19(25):25093-112. doi: 10.1364/OE.19.025093.
With the advent of Talbot-Lau interferometers for x-ray phase-contrast imaging, oblique and grazing incidence configurations are now used in the pursuit of sub-micron grating periods and high sensitivity. Here we address the question whether interferometers having oblique incident beams behave in the same way as the well-understood normal incidence ones, particularly when the grating planes are non-parallel. We derive the normal incidence equivalence of oblique incidence geometries from wave propagation modeling. Based on the theory, we propose a practical method to correct for non-parallelism of the grating planes, and demonstrate its effectiveness with a polychromatic hard x-ray reflective interferometer.
随着用于X射线相衬成像的塔尔博特-劳干涉仪的出现，现在采用倾斜和掠入射配置来追求亚微米级的光栅周期和高灵敏度。在此，我们探讨具有倾斜入射光束的干涉仪是否与人们熟知的正入射干涉仪表现相同，尤其是当光栅平面不平行时。我们通过波传播建模推导了倾斜入射几何结构的正入射等效性。基于该理论，我们提出了一种校正光栅平面不平行度的实用方法，并通过多色硬X射线反射干涉仪证明了其有效性。
