title: Two-color-laser-driven direct electron acceleration in infinite vacuum.
abstract: We propose a direct electron acceleration scheme that uses a two-color pulsed radially polarized laser beam. The two-color scheme achieves electron acceleration exceeding 90% of the theoretical energy gain limit, over twice of what is possible with a one-color pulsed beam of equal total energy and pulse duration. The scheme succeeds by exploiting the Gouy phase shift to cause an acceleration-favoring interference of fields only as the electron enters its effectively final accelerating cycle. Optimization conditions and power scaling characteristics are discussed.
authors.affiliation: Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. ljwong@mit.edu
authors.forename: Liang Jie
authors.initials: LJ
authors.lastname: Wong
authors.forename: Franz X
authors.initials: FX
authors.lastname: Kärtner
mesh_terms: D000054:Acceleration; D003116:Color; D004583:Electrons; D007700:Kinetics; D007834:Lasers