Open AccessChirp-free isolated attosecond pulse generation from an atom irradiated by a fundamental terahertz pulse synchronizing an infrared laser pulse
Author(s) -
Cheng Yan Jia,
Jun Wang,
Qingyi Li,
Fei Guo,
Ji-Gen Chen,
Siliang Zeng,
Yu-Jun Yang
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.032222
Subject(s) - optics , attosecond , multiphoton intrapulse interference phase scan , laser , physics , femtosecond pulse shaping , high harmonic generation , pulse (music) , bandwidth limited pulse , terahertz radiation , chirp , ultrashort pulse , far infrared laser , pulse duration , atomic physics , detector
We theoretically study high-order harmonic generation (HHG) and attosecond pulses from an atom irradiated synchronically by a terahertz (THz) pulse and an infrared laser pulse. For the HHG spectrum from the THz pulse alone and the combined pulse, an apparent peak-valley structure appears the platform region. Specially, for the periodic structure generated by an atom under the action of the combined pulse is originated from the interference between the electrons ionized at different instants in the laser field, which undergo many recollision and return to the core at the same time. Therefore, continuum harmonics with few chirps from the interference enhancement region can be achieved, which result in a chirp-free isolated attosecond pulse.