Fig. 1. Comparsion of shaped laser pulse and normal laser pulse. (a) Waveform comparsion of shaped laser pulse and normal laser pulse; (b) amplified partial waveforms; (c) schematic diagram of changed frequency spectrum

Fig. 2. Terahertz pulse spectra and time-domain waveforms generated by laser pulses with different pulse widths. (a) Terahertz pulse spectrum; (b) time-domain waveform

Fig. 3. Terahertz spectra and corresponding time-domain waveforms under different λ1. (a) Terahertz spectrum; (b) time-domain waveform

Fig. 4. Central frequency and spectral bandwidth of generated terahertz pulse varying with λ1. (a) Central frequency; (b) spectral bandwidth

Fig. 5. Influence of λ1 on energy of pump laser pulse

Fig. 6. Relationship between λ1 and generated terahertz pulse energy