Free-space electro-optic sampling with a high-repetition-rate regenerative amplified laser

Abstract

The use of a high-repetition-rate (250 kHz) regenerative amplified laser with μJ pulse energy in a free-space THz beam electro-optic sampling system has produced a significant improvement in both the signal-to-noise ratio ${\text{(>10}}^5)$ and absolute probe beam photomodulation depth (>19%). Focal plane images of the electric field distribution (strength and polarity) in dipole and quadrupole planar photoconductive emitters are presented. Preliminary results of real-time 2D THz images of moving objects have also been obtained.