Imaging modes in TEM

This lecture covers the imaging modes in Transmission Electron Microscopy (TEM), including the electron source, e-matter interactions, image formation, diffraction contrast, phase contrast, and Fresnel fringes. It explains how high-energy electron beams interact with specimens, produce diffraction patterns, and form images with various contrasts. The instructor discusses the principles behind bright-field and dark-field images, electron diffraction patterns, and phase contrast imaging. Additionally, the lecture explores the use of Fresnel fringes to observe and correct objective lens astigmatism, providing insights into interpreting TEM images and understanding crystal structures.