Investigation of dispersion properties of congruent lithium niobate crystal in the terahertz frequency range

Abstract

The dependences of the refractive index of a congruent LiNbO3 crystal cut perpendicular to the x and z axes on the radiation frequency in the range of 0.25–1.25 THz are presented. These dependences are presented for different values of the crystal thickness - 0.52 mm, 1 mm and 2.21 mm. A comparative analysis of the obtained dispersion curves with the results from other works is presented. The comparison was carried out by estimating the dispersion broadening of a THz pulse with time in the process of simulating its propagation in a medium with a given dispersion. It is shown that a 1.5-cycle THz pulse is broadened in media with dispersions found in other works, which does not correspond to experimental data. In accordance with this, it was concluded that the dispersion curves for congruent LiNbO3 from the considered works do not agree with the real values of the refractive index in the THz frequency range.