Development of a real-time stereo transmission electron microscope.

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. Two electrostatic deflectors make it possible to alternate the illumination direction within a blank period of 1.2 ms between two adjacent video fields. Three dimensional displays give observers a stereo impression without the need for special glasses. By considering the circle of least confusion due to spherical aberration, a lateral resolution <1 nm and a longitudinal resolution of 6.3 nm are possible with a proper defocused condition. This improvement 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(-1). Using this microscope fine particles of ZnO were observed.