High-power single-cycle THz emission from large-area photoconductive emitters at 400 kHz

We report high average power THz emission from a GaAs-based large-area photoconductive emitter, excited by a frequency-doubled, commercial Yb-laser amplifier without any pulse compression. The LAE is pumped at 11.4 W of green average power (515 nm) and 310 fs pulse duration at 400 kHz repetition rate. We obtain a maximum THz power of 6.7 mW with a spectrum extending up to 3 THz. Using electro-optical sampling (EOS) for detection, we measure a high peak dynamic range of 107 dB in a measurement time of 70 s. This is the highest power THz source so far, to the best of our knowledge, demonstrated with photoconductive emitters, based on a simple and robust, commercially available Yb-laser.