title: Efficient terahertz emission by mid-infrared laser pulses from gas targets.
abstract: It is shown by simulations that terahertz (THz) radiation can be produced more efficiently by a mid-infrared laser pulse from a gas target. The THz amplitude is enhanced by 35 times as the laser wavelength increases from 1 μm to 4 μm; a 4 μm laser at 10(15) W cm(-2) produces 5 MV/cm THz radiation. The THz amplitude changes oscillatingly with increasing laser intensity for a given laser wavelength. In addition, the laser intensity threshold for the THz emission is lower for a longer laser wavelength.
authors.affiliation: Beijing National Laboratory of Condensed Matter Physics, Institute of Physics, CAS, Beijing 100190, China. hbwwm1@iphy.ac.cn
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Wang
authors.forename: Shigeo
authors.initials: S
authors.lastname: Kawata
authors.forename: Zheng-Ming
authors.initials: ZM
authors.lastname: Sheng
authors.forename: Yu-Tong
authors.initials: YT
authors.lastname: Li
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Chen
authors.forename: Lie-Jia
authors.initials: LJ
authors.lastname: Qian
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang