Pulse quality improvement in multipass cells through dispersion engineering

We report on the experimental demonstration of enhanced-frequency-chirping (EFC) in a multipass cell (MPC) based post-compression scheme through dispersion engineering. The transfer of the nonlinear interaction into the EFC-regime facilitates a smooth spectrum void of strong modulations that are present in regular self-phase-modulated spectra. The resulting 32 fs pulses exhibit minimal side features with more than 96% of energy contained in the temporal main feature. The experiments were performed with a mJ-class Yb:fiber laser with repetition rate of 50kHz at 70 W of average power. The results show the extended capabilities for dispersion-tailored pulse propagation in MPCs.