Fig. 1. The effects of different pressures/wavelengths on GVD

Fig. 2. Selection principle of fiber core radius a

Fig. 3. Comparison of broadening for different combinations of pressure and length in Ar

Fig. 4. Comparison of broadening for different combinations of pressure and length in Kr

Fig. 5. Evolution of the pulse with the length of the hollow core fiber

Fig. 6. Pulse spectrum broadening and time domain compression

Fig. 7. Second stage compression using 38 fs pulse from first stage compression