Monday, November 19th, 2018
A Zernike phase plate can increase the image contrast in transmission electron microscopy of weak phase objects, such as biological macromolecules. However, charging effects have hindered efforts to develop such a device. We have developed a proof-of-concept phase plate based on electron phase shift by a high-intensity laser beam, which can potentially provide a stable, tunable phase shift without charging or electron loss. Using methods from the field of quantum physics, we built a laser system reaching a record continuous-wave laser intensity and achieved coherent control of electron waves. With that device, we captured electron micrographs of the light wave and demonstrated Zernike phase contrast in images of amorphous carbon film.