Physical, optical and nonlinear properties of InS single crystal

Abstract

Indium Sulphide (InS) single crystals are successfully grown by In flux. Single crystal X-ray diffraction shows orthorhombic structure of Pnnm space group. Ellipsometry measurements performed on the (010) oriented crystal exhibit low anisotropy in the 300-1000 nm wavelength range and consequently negligible THz emission is observed. Optical band gap of $2.09eV$ is deduced from linear optical measurements. Nonlinear optical properties are studied by single beam Z-scan measurements at 800 nm, where two-photon absorption is present. Nonlinear refractive index and absorption coefficient are estimated to be ${\eta }_2$ = $2.310^{-11}c{m}^2/W$ and $\beta$= $62.4cm/GW$, respectively for excitation intensity of $0.32GW/c{m}^2$. The origin of nonlinearity in InS crystal is accounted to be due to the third-order anharmonic motion of the bound electrons.

15 pages, 4 figures, 1 table