Ultra-broadband field-resolved detection using photoconductive antenna from sub-THz to near-infrared

The field-resolved detection of infrared (IR) waves is a powerful method for ultrafast spectroscopy, the extension of its bandwidth has made rapid progress. Photoconductive (PC) antenna, which detects photocurrent induced by incident electric field gated with ultra-short laser pulses, is widely used along with electro-optic sampling. In this paper, the author demonstrated ultrabroadband detection from 0.1 to 100 THz with one dipole-type PC antenna using probe pulses of 10 fs duration and a PC antenna emitter or a thin GaSe crystal. Ultra-high frequency detection up to 170 THz with the PC antenna have been demonstrated recently, using a combination of extremely short pulses with the duration of approximately 5 fs and a DAST (4-dimethylamino-N-methyl-4-stilbazollium tosylate) crystal. In this work, the spectral sensitivity of the PC antenna in mid- and near-IR region has been estimated.