Abstract

Optical filamentation of femtosecond laser pulses has recently received great attention, since it is exploited in a large number of applications [1]. During this process, the pulse undergoes significant spatial and temporal effects due to the interplay between several nonlinear phenomena, triggered by the high intensity of the self-guided beam. These effects are even more complex when the propagation occurs in a molecular medium. In this case, a delayed pulse, propagating inside the filament wake of a pump, experiences spatio-temporal reshaping as well as a spectral broadening [2] and a strong birefringence [3], due to the ultrafast refractive index change induced by the rotational excitation.

© 2011 Optical Society of America