Abstract

Because the electrostatic fields present in plasma waves can exceed those achievable in Conventional accelerators and approach atomic scale values (E_a ~ 500 GV/ m), plasma-based accelerators have received considerable attention as compact sources of high-energy electron pulses.¹ Optical probes such as stimulated Raman scattering² or terahertz radiation at ω_ρ³ have provided only spatially averaged indications of the wave’s existence. However, the ability to measure plasma wave microstructure directly is important for addressing fundamental issues of wakefield generation and propagation. We report femtosecond time-resolved measurements of the longitudinal and radial structure of laser wakefield oscillations using an ail optical technique known as photon acceleration.⁴

© 1996 Optical Society of America