Haider M, Hartel P, Müller H, Uhlemann S, Zach J
CEOS GmbH, Englerstrasse 28, 69126 Heidelberg, Germany.
Philos Trans A Math Phys Eng Sci. 2009 Sep 28;367(1903):3665-82. doi: 10.1098/rsta.2009.0121.
The achievable resolution of a modern transmission electron microscope (TEM) is mainly limited by the inherent aberrations of the objective lens. Hence, one major goal over the past decade has been the development of aberration correctors to compensate the spherical aberration. Such a correction system is now available and it is possible to improve the resolution with this corrector. When high resolution in a TEM is required, one important parameter, the field of view, also has to be considered. In addition, especially for the large cameras now available, the compensation of off-axial aberrations is also an important task. A correction system to compensate the spherical aberration and the off-axial coma is under development. The next step to follow towards ultra-high resolution will be a correction system to compensate the chromatic aberration. With such a correction system, a new area will be opened for applications for which the chromatic aberration defines the achievable resolution, even if the spherical aberration is corrected. This is the case, for example, for low-voltage electron microscopy (EM) for the investigation of beam-sensitive materials, for dynamic EM or for in-situ EM.
现代透射电子显微镜（TEM）能够达到的分辨率主要受物镜固有像差的限制。因此，在过去十年里，一个主要目标是开发像差校正器以补偿球差。现在已有这样的校正系统，利用该校正器提高分辨率成为可能。当需要TEM的高分辨率时，一个重要参数——视野，也必须加以考虑。此外，特别是对于现在可用的大型相机，补偿离轴像差也是一项重要任务。一种补偿球差和离轴彗差的校正系统正在研发中。朝着超高分辨率迈进的下一步将是开发一种补偿色差的校正系统。有了这样的校正系统，即使球差得到校正，对于那些色差决定可实现分辨率的应用领域，也将开辟一个新的应用天地。例如，对于用于研究对电子束敏感材料的低电压电子显微镜（EM）、动态EM或原位EM来说就是如此。
