Off-Axis Electron Micro-Holography

An electron micro-hologram is recorded with an off-axis arrangement, using an electron bi-prism as the beam splitter and a pointed cathode as the rotationally symmetric coherent electron source. An image with a resolution of about 20 Å is reconstructed with He–Ne laser light (λ=6328 Å). A scattered wave from the object and a direct reference beam are superposed together by means of an electron bi-prism placed behind the back focal plane of the objective lens of an electron microscope. The quality of the image reconstructed from a hologram obtained with objective over-focused is better than that of the image reconstructed from a hologram obtained with objective under-focused.