We have a new paper just published in Optics Express. It describes how we generated 144 mW of average THz power in LiNbO3 at 100 kHz. This is part of the THz &D work for LCLS-II. We used a spectrally broadened and recompressed Yb:YAG laser system with <100 fs pulse duration. The challenges here are the very high repetition rates leading to thermal issues, that need to be carefully controlled.
Read more about it here: