title: Boosting terahertz generation in laser-field ionized gases using a sawtooth wave shape.
abstract: Broadband ultrashort terahertz (THz) pulses can be produced using plasma generation in a noble gas ionized by femtosecond two-color pulses. Here we demonstrate that, by using multiple-frequency laser pulses, one can obtain a waveform which optimizes the free electron trajectories in such a way that they acquire the largest drift velocity. This allows us to increase the THz conversion efficiency to 2%, an unprecedented performance for THz generation in gases. In addition to the analytical study of THz generation using a local current model, we perform comprehensive 3D simulations accounting for propagation effects which confirm this prediction. Our results show that THz conversion via tunnel ionization can be greatly improved with well-designed multicolor pulses.
authors.affiliation: CEA-DAM, DIF, F-91297 Arpajon, France.
authors.forename: P González de Alaiza
authors.initials: PG
authors.lastname: Martínez
authors.affiliation: Institute of Quantum Optics, Leibniz University Hannover, Welfengarten 1 30167, Hannover, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Babushkin
authors.affiliation: CEA-DAM, DIF, F-91297 Arpajon, France.
authors.forename: L
authors.initials: L
authors.lastname: Bergé
authors.affiliation: Univ. Bordeaux - CNRS - CEA, Centre Lasers Intenses et Applications, UMR 5107, 33405 Talence, France.
authors.forename: S
authors.initials: S
authors.lastname: Skupin
authors.affiliation: Facultad de Óptica y Optometría, Universidad Complutense de Madrid, 28037 Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Cabrera-Granado
authors.affiliation: Institute for Scientific Computing, TU Dresden, 01062 Dresden, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Köhler
authors.affiliation: Institute of Quantum Optics, Leibniz University Hannover, Welfengarten 1 30167, Hannover, Germany.
authors.forename: U
authors.initials: U
authors.lastname: Morgner
authors.affiliation: Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Husakou
authors.affiliation: Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Herrmann