Influence of Dispersion on Dynamics of the Anti-Stokes Broadening of the Femtosecond Pulse Spectrum during Filamentation in Fused Silica

The spectrum transformation of a femtosecond wave packet during filamentation in fused silica under conditions of normal, zero, and anomalous group velocity dispersion has been investigated using numerical simulation methods. It has been shown that the generation of plasma, which induces phase modulation of the light field, leads to rapid anti-Stokes spectral broadening. It has been established that the short-wavelength shift of the broadband supercontinuum spectrum is significantly greater under anomalous group velocity dispersion compared to normal and zero dispersion. The influence of the wave packet energy on the dynamics of spectral broadening has been examined. Estimates of the numerical scheme have been obtained based on dispersion analysis of the broadband supercontinuum propagation process in the medium.