Enhancement and modulation of terahertz radiation by multi-color laser pulses*

Project supported by the National Natural Science Foundation of China (Grant No. 11604205) and the Talent Program of Shanghai University of Engineering Science, China.
Pei Min-Jie1, Lu Chen-Hui2, †, Wang Xian-Wei3, Sun Zhen-Rong1, Zhang Shi-An1, ‡
       

(color online) Time-dependent field amplitudes of harmonic five-color laser pulse (green dashed line) and uncommon five-color laser pulse with the replaceable wavelength of λ5 = 1200 nm (blue solid line) in an optical period, and the corresponding increasing rate of electron density dNe(t)/dt for the harmonic (black dotted line) and uncommon (red dash–dotted line) laser pulse.