Low- and high-frequency continuum generation by femtosecond pulses in fused silica

The dynamics of continuum generation by a superpower ultrashort pulse in fused silica is numerically simulated taking into account photon ionisation. It is found that a high-intensity femtosecond laser pulse splits during its propagation into subpulses and subbeams. The emission spectrum is shown to broaden considerably both to the high- and low-frequency regions.