Scattering of free electrons by optical fields and all-optical method for electron pulse characterization

Abstrakt

Free electrons can scatter of a standing light wave formed by two counter-propagating optical beams of identical frequency in vacuum. The coherent reflection of electron wave at periodic ponderomotive potential of the optical standing wave was first proposed by Kapitza and Dirac in 1933 [1] and it was experimentally demonstrated in 2001 [2]. The Kapitza-Dirac-like diffraction was also theoretically described for more general case with two counterpropagating light waves at different frequencies [3]. In this contribution we discuss different regimes of the interaction between electrons and light fields. Further we study the application of the classical regime of electron scattering at an optical standing wave formed by pulsed laser fields for full characterization of femtosecond electron pulses in an electron microscope [4], which is crucial for ultrafast pump-probe experiments with electron probes.

[1] Kapitza, P. L. and Dirac, P. A. M. Proc. Camb. Phil. Soc. 29, 297-300 (1933).

[2] Freimund, D. L. et al. Nature 413, 142 (2001)

[3] Smirnova, O. et al. Phys. Rev. Lett. 92, 223601 (2004)

[4] Hebeisen, C. T. et al. Opt. Express 16, 3334-3341 (2008)