Development of Super Resolution Phase Electron Microscopy

超分辨率相位电子显微镜的发展

基本信息

批准号：
10450037
负责人：
TAKAI Yoshizo
金额：
$ 2.94万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2000
项目状态：
已结题

项目摘要

In a high-resolution transmission electron microscope, the influence of a spherical aberration which intrinsically remains in the conventional magnetic lenses disturbs the interpretation for the atomic structure directly from the observed images. Defocus image modulation processing (DIMP) is one of the most promising approaches for observing spherical aberration-free phase and amplitude images with a transmission electron microscope. Since DIMP is based on a bipolar weighted image integration of the observed defocus series, all the processing of DIMP is performed in real space without Fourier transform. Therefore, the method can be rather easily applied to real-time processing by using a method of irradiation time control of a primary electron beam during accelerating voltage modulation. We have developed a real-time DIMP-EM using accelerating voltage modulation, recently. The original DIMP has presumed the observation under axial illumination, but DIMP can be extended for hollow-cone … More illumination (HCI) to realize much higher resolution, which has been already confirmed in the experiment using an optical microscope. In the present research, DIMP has been extended to HCI using an electron microscope for the first time. The processed image showed 10% higher resolution than the information limit, resulting in the realization of super resolution phase electron microscope having higher resolution than its attainable resolution under axial illumination.As another method to achieve super resolution electron microscopy, three dimensional Fourier filtering method has been mathematically derived using a proposed three dimensional image formation theory. Phase and amplitude images with spherical aberration correction has been confirmed in experiments. In the results, the resolution of the reconstructed phase image was improved from Scherzer resolution limit to the information limit because of the correction of spherical aberration. The 3D Fourier filtering method can be also applied to correct comprehensive aberrations, such as astigmatic aberration and coma aberration. Less

在高分辨率透射电子显微镜中，传统磁透镜中固有的球差影响直接从观察到的图像中干扰了原子结构的解释，散焦图像调制处理（DIMP）是最有前途的方法之一。用于用透射电子显微镜观察无球面像差的相位和振幅图像由于 DIMP 基于观察到的散焦序列的双极加权图像积分，因此 DIMP 的所有处理都是在实空间中进行的，无需任何处理。因此，通过在加速电压调制期间使用一次电子束的照射时间控制方法，该方法可以相当容易地应用于实时处理，我们开发了一种使用加速电压调制的实时DIMP-EM。最近，原始的 DIMP 假设在轴向照明下进行观察，但 DIMP 可以扩展到空心锥照明（HCI）以实现更高的分辨率，这已经在实验中得到了证实。在目前的研究中，DIMP首次扩展到HCI，使用电子显微镜处理后的图像显示出比信息极限高10%的分辨率，从而实现了具有比信息极限更高的分辨率的超分辨率相电子显微镜。作为实现超分辨率电子显微镜的另一种方法，使用提出的三维图像形成理论从数学上导出了三维傅里叶滤波方法，并在 2017 年证实了具有球面像差校正的相位和幅度图像。实验结果表明，由于球面像差的校正，重建相位图像的分辨率从Scherzer分辨率极限提高到了信息极限。3D傅立叶滤波方法还可以应用于校正像散像差和像差等综合像差。彗差较小。