Properties of femtosecond laser-induced defects in alkali metal fluoride crystals

The formation of various defects in the crystal lattice of lithium and sodium fluorides under the action of femtosecond laser pulses is described. The difference between the concentration distributions of aggregate color centers and light-scattering nanodefets in the channels is shown. The effect geometrical focusing has on color center formations is demonstrated. The observed phenomena are explained by the nonlinear processes induced by high-intensity femtosecond pulses.