Paper concerns experimental and numerical investigation on supercontinuum emission in the process of femtosecond beam filamentation under different geometrical focusing in presence of anomalous group velocity dispersion in fused silica. It was shown that energy of supercontinuum visible part increases discretely with increasing of input laser pulse energy. It is connected with light bullets formation. Also it was found that energy of supercontinuum visible part connected with each bullet doesn’t depend on focusing geometry.
The Supercontinuum (SC) generation during femtosecond laser pulse filamentation with various central wavelengths
in fused silica is investigated by numerical solution of nonlinear Schroedinger equation. Material dispersion of the
medium is considered due to Sellmeier formula. Nonmonotonic dependence of spectral intensity on wavelength in
anti-Stokes wing for anomalous group velocity dispersion (GVD) region (λ<sub>0</sub> = 1900 nm) was found. There is a local
minimum in SC spectrum from 800 nm to 1200 nm, and there is also a local maximum in SC spectrum from 400 nm
to 700 nm. We suppose such modification of pulse spectrum during filamentation process to be caused by
interference modulation of SC spectrum in presence of anomalous GVD.