Fig. 1. The slow turn-on, rapid turn-off laser pulse (blue line), its SH pulse (red line), their combined pulse (black line), and a normal pulse shape in the temporal domain (purple dashed line). (a) is the whole figure, and (b) is its magnified partition from −50 fs to −40 fs

Fig. 2. Plasma currents produced by the two-color normal laser pulses and the shaped laser pulses(The other parameters are introduced in the text)

Fig. 3. Temporal waveforms of the THz pulses (a) and their frequency spectra (b) produced by the normal laser pulses and the shaped laser pulses

Fig. 4. (a) Evolution of the THz peak amplitude with the phase difference; (b) All the THz pulses in the temporal with different phases in two-dimension (Note that the THz pulses are normalized in the (b) in order to show the evolution clearly)

Fig. 5. Relations between the THz peak amplitude and the laser intensity (The normal two-color laser scheme and the special shaped laser pulse are plotted together to show their difference)

Fig. 6. THz peak amplitude changes with the increase of the parameter τ₀ (The other parameters are same to that used in the Fig. 3)