Optimizing the electro-optic detection of terahertz waves by ZnTe at 780 and 1560-nm probe-beam wavelengths

Abstract

Investigations were made for optimizing ZnTe as a THz detector at 1560-nm probe beam wavelength, and was compared with its performance at 780[Formula: see text]nm. High-sensitive THz detection was achieved when phase matching was maintained for long coherence lengths between the probe beam and the incident THz waves. A 1-mm thick ZnTe crystal enabled detection bandwidths of THz radiation up to 2 and 3 THz with probe wavelengths at 1560 and 780[Formula: see text]nm, respectively. Theoretical calculations showed coherence length of less than 50[Formula: see text][Formula: see text]m in ZnTe between the THz wave components above 4 THz and the optical waves at 780 and 1560[Formula: see text]nm.