Colloquium - Professor Brett Barwick; Associate Professor of Physics, Harrison E. Farnsworth 1918 Chair in Physics, Ripon College
"Using Ultrafast Electron Microscopy to Study Fundamental Electron Photon Interactions" by Brett Barwick, Ph.D., Associate Professor of Physics, Harrison E. Farnsworth 1918 Endowed Chair in Physics, Ripon College
Abstract: In this talk I will discuss how ultrafast electron microscopy techniques can be used to study fundamental electron-photon interactions. One of these interactions involves transferring quantized amounts of orbital angular momentum (OAM) from photons to electrons using the Kapitza-Dirac effect with photons carrying OAM. This technique would enhance the sensitivity of ultrafast electron microscopes, electron interferometers and provide a new method of shaping the spatial properties of electron beams. In related experiments we are also attempting to use all-optical techniques to compress free electron pulses from 100’s of femtoseconds to tens of femtoseconds or shorter. If these efforts are successful the temporal resolution of ultrafast electron microscopes would be improved by more than an order of magnitude, allowing dynamics of systems that have motions too fast for current technologies to be explored.