Generation of high-fidelity sub-10-fs milIijoule pulses through filamentation for relativistic laser-matter experiments at 1 kHz

We report the efficient generation of high-fidelity 1.8-mJ, 9.6-fs pulses at a 1-kHz repetition through filamentation of 3.6-mJ, 42-fs pulses in an argon pressure-gas cell. Pulses emerging from the 65-cm-long filament channel are spectrally broadened and carry an unexpected large negative group delay dispersion of more than −500 fs2. Post-compression down to sub-10-fs duration thus does not require the use of chirped mirrors since the essentially linear negative chirp can be compensated by simple linear propagation through a combination of different glasses. The good shot-to-shot stability, exceptional peak-to-pedestal contrast ratio and good focusability of this source are sufficient to drive relativistic laser-solid target interactions at 1-kHz.