Spatio-Temporal Characterization of Sub-5-fs Pulses Obtained by Filamentation

Summary form only given. Pulse compression through filamentation to the two-optical-cycle regime has been demonstrated, including its capability of maintaining the carrier-envelope-offset (CEO) phase. Simulations reproduce these results well but also indicate significant spatial structure in the output beam calling for spatio-temporal characterization of these pulses. We used 30-fs pulses centered at 795 nm with energies of up to 1 mJ, to generate ultra-short pulses by filamentation in two subsequent cells filled with Argon at an absolute pressure of 900 mbar and 820 mbar, respectively. We investigated the spatial dependence of the temporal profile and phase of these output pulses by spatially selecting a part of the output beam.