Open AccessEnhanced terahertz radiation by an intense femtosecond laser field assisted with sub-cycle pulses
Author(s) -
Xiao-Fang Shu,
Chengjun Yu,
Jie Liu
Publication year - 2019
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.27.007751
Subject(s) - terahertz radiation , physics , radiation , laser , femtosecond , optics , ionization , electric field , electron , terahertz spectroscopy and technology , optoelectronics , ion , quantum mechanics
In this work, we theoretically investigate the enhanced Terahertz (THz) radiation by an intense laser pulse assisted with sub-cycle pulses (SCP) in the framework of quantum theory. By numerically solving the Schrödinger equation, the production and the dynamics of ionized electrons are analyzed. The simulations show that the SCP plays different roles for different time delays in the generation of THz radiation, such as increasing the production of the ionized electrons and manipulating their trajectories. The time-frequency analysis of the THz radiation is also carried out, which indicates that the THz radiation mainly occurs where the SCP is launched, and the THz radiation mainly comes from the formation of the asymmetric electric current. Finally, the scheme of dual sub-cycle pulses is studied, and we find that the THz radiations can constructively or destructively interfere, which leads to the formation of the streaky structures of radiation spectra.