Theoretical investigation on generating terahertz radiation from gas plasma induced by three-color ultrashort lasers
Wang Cheng-Lianga), Yang Zhen-Gangb), Liu Jin-Songa), Wang Sheng-Lieb), Wang Ke-Jia†a)
       
Laser electric fields and electron densities versus time in case (iv) (blue line), (v) (green line), and (vi) (red line). (a): Overall trend. (b)–(d): Zoomed portion of curves in panel (a).