Photon statistics and signal to noise ratio for incoherent diffraction imaging
Photon statistics and signal to noise ratio for incoherent diffraction imaging
复制标题
非相干衍射成像的光子统计和信噪比
DOI：
--
复制
发表时间：
2020
影响因子：
3.3
通讯作者：
H. Chapman
中科院分区：
文献类型：
--
作者：
F. Trost;K. Ayyer;H. Chapman
强度干涉测量法在天文学中是一种众所周知的方法。最近提出了一种相关的方法，称为非相干衍射成像（IDI），利用x射线荧光辐射的强度相关性来确定样品中发射原子的三维排列。在这里，我们讨论了影响IDI的固有噪声源，并推导了一个模型来估计信噪比（SNR）对每像素光子数、时间相干性（或模式数）和成像物体形状的依赖。进行了二维和三维的模拟来验证模型的预测。我们发现与相干成像方法相反，更高的强度和更高的检测计数并不总是对应于更大的信噪比。此外，较大和更复杂的对象通常产生较差的信噪比，尽管较高的测量计数。这里开发的框架应该对未来的实验设计有价值的指导。
Intensity interferometry is a well known method in astronomy. Recently, a related method called incoherent diffractive imaging (IDI) was proposed to apply intensity correlations of x-ray fluorescence radiation to determine the 3D arrangement of the emitting atoms in a sample. Here we discuss inherent sources of noise affecting IDI and derive a model to estimate the dependence of the signal to noise ratio (SNR) on the photon counts per pixel, the temporal coherence (or number of modes), and the shape of the imaged object. Simulations in two- and three-dimensions have been performed to validate the predictions of the model. We find that contrary to coherent imaging methods, higher intensities and higher detected counts do not always correspond to a larger SNR. Also, larger and more complex objects generally yield a poorer SNR despite the higher measured counts. The framework developed here should be a valuable guide to future experimental design.