  Ionizing 800-nm femtosecond laser pulses propagating in silica glass and in
potassium dihydrogen phosphate (KDP) crystal are investigated by means of a
unidirectional pulse propagation code. Filamentation in fused silica is
compared with the self-channeling of light in KDP accounting for the presence
of defect states and electron-hole dynamics. In KDP, laser pulses produce
intense filaments with higher clamping intensities up to 200 TW/cm$^2$ and
longer plasma channels with electron densities above $10^{16}$ cm$^{-3}$.
Despite these differences, the propagation dynamics in silica and KDP are
almost identical at equivalent ratios of input power over the critical power
for self-focusing.
