Development of a real time stereo phase microscope

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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