Fig. 1. Schematic diagram of φ'₁(t) changing with time

Fig. 2. Schematic diagram of φ'₂(t) changing with time

Fig. 3. Schematic diagram of spectral change experimental device for specific phase modulation

Fig. 4. Schematic diagram of spectral broadening obtained by changing the relative position of pulsed light and modulated signal

Fig. 5. Spectrum images obtained by CCD for f₁(t)-modulating at different time. (a) t=1 ps; (b) t=664 ps; (c) t=1245 ps; (d) t=1826 ps; (e) t=2407 ps; (f) t=2988 ps

Fig. 6. Spectrum width of f₁(t)-modulated pulsed light

Fig. 7. Spectrum width of f₂(t)-modulated pulsed light