Electro-Optic Sampling of Terahertz Waves Under Brewster’s Angle

We investigate the angular dependence of electro-optic sampling of terahertz radiation. We show that a non-perpendicular incident of copropagating terahertz and optical waves onto the electro-optic crystal only weakly influences the resulting electro-optic sensing efficacity while strongly reduces disturbing multiple reflections within the crystal. We found that close to Brewster’s angle, the detectors response is most favorable. Experimental data support our theoretical discussion.