Grating enhanced ponderomotive scattering for visualization and full characterization of femtosecond electron pulses.

Real time views of atomic motion can be achieved using electron pulses as structural probes. The requisite time resolution requires knowledge of both the electron pulse duration and the exact timing of the excitation pulse and the electron probe to within 10 - 100 fs accuracy. By using an intensity grating to enhance the pondermotive force, we are now able to fully characterize electron pulses and to confirm many body simulations with laser pulse energies on the microjoule level. This development solves one of the last barriers to the highest possible time resolution for electron probes.