Terahertz emission from in-plane and out-of-plane dipoles in layered SnS2 crystal

Abstract

We investigated the terahertz (THz) radiation mechanism of the layered tin sulfide (SnS2) crystal via THz emission spectroscopy. Under non-resonant excitation, THz generation from SnS2 is mainly due to the optical rectification effect, which is verified by the azimuthal angle, polarization angle, and pump fluence dependence of the THz signals. Further incident angle dependent THz signals suggest that the optical progress happened at the surface of SnS2 with both in-plane and out-of-plane photon-induced dipoles. This work puts forward THz emission spectroscopy as a noninvasive characterization tool for the in-plane and out-of-plane photon-induced dipoles in layered materials.