title: Frequency modulation of high-order harmonic fields with synthesis of two-color laser fields.
abstract: We report periodical frequency modulation of high-order harmonic fields observed by changing the delay between the driving two-color laser fields consisting of the fundamental and its second harmonic (SH) field. The amplitude of modulation has been up to ∼0.4 eV, which is larger than the bandwidth of the fundamental field. Experimental results show that the intensity and chirp of the fundamental field can control this phenomenon. Numerical analysis by solving the time-dependent Schrödinger equation approves of these results and shows that anharmonic frequency components of the SH field have a crucial role in this phenomenon.
authors.affiliation: RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan. amani@riken.jp
authors.forename: A
authors.initials: A
authors.lastname: Amani Eilanlou
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Nabekawa
authors.forename: Kenichi L
authors.initials: KL
authors.lastname: Ishikawa
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takahashi
authors.forename: Eiji J
authors.initials: EJ
authors.lastname: Takahashi
authors.forename: Katsumi
authors.initials: K
authors.lastname: Midorikawa