Scalable terahertz generation by large-area optical rectification at 80 TW laser power

We demonstrate high-energy terahertz generation from a large-aperture (75 mm diameter) lithium niobate wafer by using a femtosecond laser with energy up to 2 J. This scheme utilizes optical rectification in a bulk lithium niobate crystal, where most terahertz energy is emitted from a thin layer of the rear surface. Despite its simple setup, this scheme can yield 0.19 mJ of terahertz energy with laser-to-terahertz conversion efficiencies of ~0.01%, about 3 times better than ZnTe when pumped at 800 nm. The experimental setup is up-scalable for multi-mJ terahertz generation with petawatt laser pumping.