论文标题
光子统计量和信号与噪声比不相干衍射成像
Photon statistics and signal to noise ratio for incoherent diffraction imaging
论文作者
论文摘要
强度干涉法是天文学中众所周知的方法。最近，提出了一种称为不一致的衍射成像（IDI）的相关方法，以应用X射线荧光辐射的强度相关性，以确定样品中发射原子的3D排列。在这里，我们讨论了影响IDI的固有噪声源并得出模型，以估计信号对噪声比（SNR）对每个像素的光子计数，时间相干性（或模式的数量）以及成像对象的形状的依赖性。已经进行了二维和三维中的模拟，以验证模型的预测。我们发现，与一致的成像方法相反，较高的强度和更高的检测到的计数并不总是与较大的SNR相对应。而且，尽管计数较高，但较大且更复杂的物体通常会产生较差的SNR。这里开发的框架应该是未来实验设计的宝贵指南。
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.
