title: Optical gating and streaking of free electrons with sub-optical cycle precision.
abstract: The temporal resolution of ultrafast electron diffraction and microscopy experiments is currently limited by the available experimental techniques for the generation and characterization of electron bunches with single femtosecond or attosecond durations. Here, we present proof of principle experiments of an optical gating concept for free electrons via direct time-domain visualization of the sub-optical cycle energy and transverse momentum structure imprinted on the electron beam. We demonstrate a temporal resolution of 1.2±0.3 fs. The scheme is based on the synchronous interaction between electrons and the near-field mode of a dielectric nano-grating excited by a femtosecond laser pulse with an optical period duration of 6.5 fs. The sub-optical cycle resolution demonstrated here is promising for use in laser-driven streak cameras for attosecond temporal characterization of bunched particle beams as well as time-resolved experiments with free-electron beams.
authors.affiliation: Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Staudtstrasse 1, 91058 Erlangen, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Kozák
authors.affiliation: Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Staudtstrasse 1, 91058 Erlangen, Germany.
authors.forename: J
authors.initials: J
authors.lastname: McNeur
authors.affiliation: Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA.
authors.forename: K J
authors.initials: KJ
authors.lastname: Leedle
authors.affiliation: Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA.
authors.forename: H
authors.initials: H
authors.lastname: Deng
authors.affiliation: Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Staudtstrasse 1, 91058 Erlangen, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Schönenberger
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Ruehl
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, D-22607 Hamburg, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Hartl
authors.affiliation: Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA.|Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Harris
authors.affiliation: Department of Applied Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Byer
authors.affiliation: Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Staudtstrasse 1, 91058 Erlangen, Germany.|Max-Planck-Institute for the Science of Light, Staudtstrasse 2, 91058 Erlangen, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Hommelhoff