Performance of MgO:PPLN, KTA, and KNbO3 for mid-wave infrared broadband parametric amplification at high average power

The performance of KNbO3, MgO:PPLN and KTA were experimentally compared for broadband mid-wave infrared parametric amplification at high repetition rate. The seed pulses with an energy of 6.5 μJ were amplified using 410 μJ of pump at 1064 nm to a maximum pulse energy of 28.9 μJ at 3 μm wavelength and at 160 kHz repetition rate in MgO:PPLN while supporting a transform limited duration of 73 fs. The high average powers of the interacting beams used in this study, revealed average power induced processes which limit the scaling of optical parametric amplification: in MgO:PPLN the pump peak intensity was limited to 3.8 GW/cm2 due to non-permanent beam reshaping while in KNbO3 an absorptioninduced temperature gradient in the crystal led to permanent internal distortions in the crystal structure when operated above a pump peak intensity of 14.4 GW/cm2Peer Reviewe