Fig. 1. Schematic of 4F shaping technique of ultrashort laser pulse

Fig. 2. Laser pulse shaping spectrum and pulse envelopes before and after shaping. (a) Ultrashort laser pulse with partial frequency components truncated in the frequency domain; (b) pulse envelopes after the pulse truncated

Fig. 3. Terahertz pulses generated by different pulse-shaping parameters. (a) Frequency spectra of terahertz pulses; (b) terahertz time-domain waveforms

Fig. 4. Influences of laser pulse-shaping parameters on the terahertz pulse central frequency. (a) Change of central frequency in the high band; (b) change of central frequency in the low band

Fig. 5. Influences of laser pulse-shaping parameters on the amplitude. (a) Change of amplitude in the high band; (b) change of amplitude in the low band