Abstract

The optical Kerr effect (OKE) produces an intensity dependent refractive index change which gives rise to self-phase modulation (SPM). SPM leads to changes in laser pulse duration by affecting the phase of the laser pulse. Here we explore the transient behavior of fused silica and find that the OKE-induced phase changes are accompanied by significant changes in the magnitude and sign of the group velocity dispersion (GVD). We find that material dispersion, which is a key parameter for all femtosecond laser applications, is not a constant and this should be taken into consideration. The OKE phase shift in time domain expected from the light-matter interaction can be written as

© 2013 IEEE