School of Physics, Monash University, Clayton, Victoria, Australia, 3800.
Opt Lett. 2011 Jan 1;36(1):55-7. doi: 10.1364/OL.36.000055.
The ability to quantitatively retrieve transverse phase maps during imaging by using coherent x rays often requires a precise grating or analyzer-crystal-based setup. Imaging of live animals presents further challenges when these methods require multiple exposures for image reconstruction. We present a simple method of single-exposure, single-grating quantitative phase contrast for a regime in which the grating period is much greater than the effective pixel size. A grating is used to create a high-visibility reference pattern incident on the sample, which is distorted according to the complex refractive index and thickness of the sample. The resolution, along a line parallel to the grating, is not restricted by the grating spacing, and the detector resolution becomes the primary determinant of the spatial resolution. We present a method of analysis that maps the displacement of interrogation windows in order to retrieve a quantitative phase map. Application of this analysis to the imaging of known phantoms shows excellent correspondence.
利用相干 X 射线在成像过程中定量获取横向相位图的能力通常需要精确的光栅或分析晶体基础设置。当这些方法需要多次曝光进行图像重建时，对活体动物的成像会带来进一步的挑战。我们提出了一种简单的单曝光、单光栅定量相位对比方法，适用于光栅周期远大于有效像素尺寸的情况。光栅用于创建入射到样品上的高可见度参考图案，该图案根据样品的复折射率和厚度发生变形。与光栅平行的线的分辨率不受光栅间距的限制，探测器分辨率成为空间分辨率的主要决定因素。我们提出了一种分析方法，该方法映射询问窗口的位移以获取定量相位图。该分析方法在已知的幻影成像中的应用显示出极好的一致性。
