Image transfer with spatial coherence for aberration corrected transmission electron microscopes
Image transfer with spatial coherence for aberration corrected transmission electron microscopes
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DOI：
10.1016/j.ultramic.2016.04.010
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发表时间：
2016-08-01
期刊：
影响因子：
2.2
通讯作者：
Sannomiya, Takumi
中科院分区：
文献类型：
--
作者：
Hosokawa, Fumio;Sawada, Hidetaka;Sannomiya, Takumi
对于像差校正的透射电子显微镜，导出了涉及像差高达六倍像散的空间相干性公式。利用新导出的公式计算了带有若干残余像差的线性成像传递函数。根据像差的对称性和起源，计算得到的传递函数显示出特征对称性。来自场分量的像差，沿z方向具有均匀性，即n倍像散，显示出相干性的旋转对称阻尼。来自于场对z的导数的像差，如彗差、星差和三瓣差，显示出非旋转对称阻尼。证实了奇对称波像差对图像的空间相干衰减有影响。血红蛋白和Si的图像模拟的例子[211]显示了使用空间相干的像差校正电子显微镜。(C) 2016 Elsevier B.V.版权所有
The formula of spatial coherence involving an aberration up to six-fold astigmatism is derived for aberration-corrected transmission electron microscopy. Transfer functions for linear imaging are calculated using the newly derived formula with several residual aberrations. Depending on the symmetry and origin of an aberration, the calculated transfer function shows characteristic symmetries. The aberrations that originate from the field's components, having uniformity along the z direction, namely, the n-fold astigmatism, show rotational symmetric damping of the coherence. The aberrations that originate from the field's derivatives with respect to z, such as coma, star, and three lobe, show non rotational symmetric damping. It is confirmed that the odd-symmetric wave aberrations have influences on the attenuation of an image via spatial coherence. Examples of image simulations of haemoglobin and Si [211] are shown by using the spatial coherence for an aberration-corrected electron microscope. (C) 2016 Elsevier B.V. All rights reserved.