Abstract

The electric field in the focus of an ultrafast laser pulse of sufficient energy can reach extremely high values; for I = 10¹⁹ W/cm², $E_{\text{rms}}=\sqrt{Z_{0}I}\sim 6\times {10}^{10}\text{V}/\text{cm}$. When a high energy electron traverses the laser focus, it experiences in its own rest-frame a field E^* = 2γE_rms where γ = ε/mc² is the Lorentz factor of the electron [ε is the energy and mc² the rest mass of the electron]. In the present experiment, electrons from the Stanford Linear Accelerator collided with a frequency doubled pulse from a Nd:glass laser system.

© 1996 Optical Society of America