Two-center interference in high-harmonic generation of in a combination of a mid-infrared laser field and a terahertz field
Zhang Jun, Pan Xue-Fei, Xu Tong-Tong, Zhang Hong-Dan, Du Hui, Guo Jing, Liu Xue-Shen
       

(color online) Harmonic spectra obtained from the dipole acceleration (solid black curve) and (dashed red curve) in (a) the mid-infrared laser pulse and (b) the combined laser pulse.