Conical-emission and shock-front dynamics in femtosecond laser-pulse filamentation

We investigate both experimentally and numerically the space-time dynamics of an ultrashort laser pulse during self-focusing and nonlinear propagation in water by means of a time-gated angular-spectrum characterization. The results identify the formation of shock fronts on both trailing and leading edges of the wave packet that are due to the formation of subluminal and superluminal group velocity intensity peaks, sustained by conical emission

High power, subpicosecond, 750-1770 nm tunable pulses from travelling wave parametric generator

Transform limited subpicosecond pulses have been obtained by parametric conversion of the second harmonic of a short pulse generated by a Nd:glass laser system. The arrangement consists of a KDP followed by a BBO respectively with type II and type I phase-matching, pumped in a travelling wave configuration without any spectral selecting element between them. It provides tunability from 750 to 1770 nm with pulses as short as 0.6 ps. Pulse energies above 50 \u3bcJ, with a total conversion efficiency of 13%, have been achieve

Space-time dynamics of ultrashort light pulses in water

We monitor the space-time transformation of 150-fs pulse, which undergoes self-focusing and filamentation in water, by means of the nonlinear gating technique and provide full characterization of the resultant wave packet