Mid-infrared quasi-parametric chirped-pulse amplification based on Sm:LGN crystals.

We numerically demonstrate highly efficient mid-infrared quasi-parametric chirped-pulse amplification (QPCPA) based on a recently developed Sm-doped LaGaNbO (Sm:LGN) crystal. At pump wavelength around 1 µm, the broadband absorption of Sm on idler pulses can enable QPCPA for femtosecond signal pulses centered at 3.5 or 5 µm, with a conversion efficiency approaching the quantum limit. Due to suppression of back conversion, such mid-infrared QPCPA exhibits robustness against phase-mismatch and pump-intensity variation. The Sm:LGN-based QPCPA will provide an efficient approach for converting currently well-developed intense laser pulses at 1 µm to mid-infrared ultrashort pulses.