High power 9 µm source for spectroscopy and HHG

High power mid-infrared (MID-IR) laser systems delivering ultrashort pulses at high repetition rates are of considerable interest for vibrational spectroscopy, label-free microscopy, ultrafast dynamics and HHG studies. To meet these requirements, we developed an optical parametric chirped-pulse amplifier (OPCPA) with a difference frequency generation (DFG) stage to provide an efficient platform to down-convert a 200 W Yb-YAG pump laser into the MID-IR range. The MID-IR pulses are tunable from 4.2-11 μm, with a maximum pulse energy around 9 μm with 2.2 μJ at 200 kHz supporting a Fourier limit of 50 fs. In addition, thermal parameters of various nonlinear crystals are reviewed for high power MID-IR OPCPAs.