Experimental study of filamentation and supercontinuum generation in laser-modified fused silica

In this paper we present experimental results on the behaviour of light supercontinuum generation and filamentation when ultrafast laser induced material modifications are accumulating in fused silica. We show that due to material modification supercontinuum spectrum starts to shrink and its intensity rapidly decreases; this rate is highly affected by the laser pulse repetition rate. The filament tends to split along the beam propagating path resulting in inhomogeneous distribution of the modified material.