Few-cycle pulse generation by double-stage hybrid multi-pass multi-plate nonlinear pulse compression.

Few-cycle pulses present an essential tool to track ultrafast dynamics in matter and drive strong field effects. To address photon-hungry applications, high average power lasers are used which, however, cannot directly provide sub-100-fs pulse durations. Post-compression of laser pulses by spectral broadening and dispersion compensation is the most efficient method to overcome this limitation. We present a notably compact setup which turns a 0.1-GW peak power, picosecond burst-mode laser into a 2.9-GW peak power, 8.2-fs source. The 120-fold pulse duration shortening is accomplished in a two-stage hybrid multi-pass, multi-plate compression setup. To our knowledge, neither shorter pulses nor higher peak powers have been reported to-date from bulk multi-pass cells alone, manifesting the power of the hybrid approach. It puts, for instance, compact, cost-efficient, and high repetition rate attosecond sources within reach.