Development of a real time stereo phase microscope

透射电子显微镜（TEM）图像本质上是标本的二维投影，其中沿入射电子束方向的信息丢失。然而，在材料科学研究中，通过透射电镜进行三维观测是不可缺少的，可以观察位错、析出物、空隙等。此外，它也是生物医学科学中非常有效的技术，例如，用于细胞膜和神经组织的结构分析。立体电子显微术的原理是在20世纪40年代提出的，此后，利用立体三维观察进行了许多研究。这种立体缩微术是用倾斜的标本沿两个不同方向投影的两张缩微照片，将胶片冲洗出来，最后用特殊的眼镜观察。计算机断层扫描技术（Computer tomography， CT）于20世纪80年代初被引入分子生物学领域，并将电子成像技术与电子衍射技术相结合，发展成为电子晶体成像技术。最近，电子显微镜机械精度的提高和智能软件的发展鼓励了使用CT进行三维重建。所有的电子显微镜制造商都强制在其显微镜上安装CT系统，该系统可以快速获取图像序列并自动重建。到目前为止，在TEM中用于三维成像的技术要求标本保持稳定，因为立体方法需要通过倾斜标本沿不同方向投影两个图像，而CT需要经常获取图像，这可能需要几十秒到几个小时。在这项研究中，一种新的透射电子显微镜，允许立体观察在实时视频速率已开发。为了在高速下形成立体对，采用了从两个方向照射而不是倾斜照射的方法。三维显示器给观察者一个立体的印象，而不需要特殊的眼镜。在适当的散焦条件下，横向分辨率小于1nm，纵向分辨率为6.3 nm是可能的。这种分辨率的期望在金细粒子的图像中得到了证实。可以检测到物体在横向上的运动，速度可达8.3 nm/s。用该显微镜观察了铝和不锈钢薄膜中ZnO的细小颗粒和位错。该显微镜可用于立体电子全息显微镜。将立体电子全息显微镜与光学重建系统相结合，确定了实时立体电子全息的实现。少

Transmission electron microscope(TEM) images are intrinsically two-dimensional projections of specimens wherein information along the incident electron beam direction is lost. Three-dimensional(3-D) observations by TEM, however, are indispensable in material science studies for observing dislocations, precipitates, voids, and so on. Moreover, it is also a very effective technique in biomedical sciences, for example, for structure analysis of cell membranes and nervous tissues. The principle of stereoscopic electron micrography was proposed in 1940s, thereafter, many investigations using stereographic 3-D observation have been carried out. Such stereoscopic microcopy is that we take two micrographs projected along two different directions with tilting specimens and develop the films and print them, then we can observe by special glasses at last. Computer tomography(CT) was introduced in the early 1980s, especially in molecular biology it has been developed into the electron crystallogra … More phy by combining the electron imaging with the electron diffraction. Recently, progressive mechanical accuracy of electron microscopes and the development of clever software have encouraged 3-D reconstructions using CT. All electron microscope manufacturers enforce installing the CT system to their microscopes, which can acquire image series quickly and automatically reconstruct. The techniques used thus far in TEM for 3-D imaging require the specimens to be stable, because the stereo method requires taking two images projected along the different directions by tilting a specimen, and the CT necessitates the acquisition oftens of images, which can take several tens of seconds to a few hours.In this research, a new transmission electron microscope that allows for stereoscopic observations in real time at a video rate has been developed. In order to make stereo pairs at a high speed, illumination of a specimen from two directions instead of specimen tilting is adopted. Three dimensional displays give observers a stereo impression without the need for special glasses. A lateral resolution less than 1 nm and a longitudinal resolution of 6.3 nm are possible with a proper defocused condition. This expectation of the resolution is confirmed for the image of Au fine particles. The motion of objects in the lateral direction can be detected up to a speed of 8.3 nm/s. Fine particles of ZnO and dislocations in aluminum and stainless steal thin films were observed using this microscope. This microscope can be utilized to a stereoscopic electron holograph microscope. Realization of real time stereoscopic electron holography is confirmed by combining a stereoscopic electron holography microscope and an optical reconstruction system. Less