2D layered SiP as anisotropic nonlinear optical material

Two-dimensional (2D) material of silicon phosphide (SiP) has recently been shown as a promising optical material with large band gap, fast photoresponse and strong anisotropy. However, the nonlinear optical properties of 2D SiP have not been investigated yet. Here, the thickness-dependent in-plane anisotropic third-harmonic generation (THG) from the mechanically exfoliated 2D layered SiP flakes is reported. The crystal orientation of the SiP flake is determined by the angle-resolved polarized Raman spectroscopy. The angular dependence of the THG emission with respect to the incident linear polarization is found to be strongly anisotropic with the two-fold polarization dependence pattern. Furthermore, the effect of the SiP flake thickness on the THG power is analyzed.

Automated summary

The 2D material silicon phosphide (SiP) shows promising optical properties, including a large band gap, fast photoresponse, and strong anisotropy. The study investigates the thickness-dependent in-plane anisotropic third-harmonic generation (THG) from mechanically exfoliated 2D SiP flakes, revealing a strong anisotropic angular dependence of THG emission with respect to incident linear polarization.