title: Attosecond nonlinear optics using gigawatt-scale isolated attosecond pulses.
abstract: High-energy isolated attosecond pulses required for the most intriguing nonlinear attosecond experiments as well as for attosecond-pump/attosecond-probe spectroscopy are still lacking at present. Here we propose and demonstrate a robust generation method of intense isolated attosecond pulses, which enable us to perform a nonlinear attosecond optics experiment. By combining a two-colour field synthesis and an energy-scaling method of high-order harmonic generation, the maximum pulse energy of the isolated attosecond pulse reaches as high as 1.3 μJ. The generated pulse with a duration of 500 as, as characterized by a nonlinear autocorrelation measurement, is the shortest and highest-energy pulse ever with the ability to induce nonlinear phenomena. The peak power of our tabletop light source reaches 2.6 GW, which even surpasses that of an extreme-ultraviolet free-electron laser.
authors.affiliation: Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, 2-1 Hirosawa, Wako-shi 351-0198, Japan.
authors.forename: Eiji J
authors.initials: EJ
authors.lastname: Takahashi
authors.forename: Pengfei
authors.initials: P
authors.lastname: Lan
authors.forename: Oliver D
authors.initials: OD
authors.lastname: Mücke
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Nabekawa
authors.forename: Katsumi
authors.initials: K
authors.lastname: Midorikawa