Sampling of broadband terahertz pulses with thick electro-optic crystals

The authors show by experiment and theory that thick electro-optic crystals are suitable media for sampling electromagnetic radiation from 0.3 to 50 THz with 10 fs visible laser pulses. For example, the detection of frequencies above 10 THz with a 250 mu m thick, < 110 >-oriented ZnTe crystal is as efficient as that with a 10 mu m thin crystal. This surprising behavior and a much flatter detector response arise because phase-matching oscillations are greatly smeared out by the broad spectrum of the sampling pulse and the crystal dispersion. (c) 2007 American Institute of Physics.