Optical dispersion, permittivity spectrum and thermal-lensing effect in nickel-doped zinc sulfide nanoparticles

In this paper, Ni-doped ZnS (ZnS:Ni2+) nanoparticles (NPs) have been prepared through a chemical method. The average size of the particle is 45 nm. Thin films of the particles have been prepared by using the spin-coating method. The linear and nonlinear optical properties of Ni-doped ZnS thin films and the colloidal solution of them have been studied widely. Using a precise numerical method, the refractive index curve (dispersion curve), absorption coefficient and optical permittivity of Ni-doped ZnS film have been obtained. Using these values, the absorption coefficient of the colloidal solution of Ni-doped ZnS particles has been simulated and compared with experimental results. Finally, using the z-scan method at low laser irradiation, the thermo-optical effect has been studied and the nonlinear refractive index due to this effect has been reported

Synthesis and nonlinear optical characterization of nanocrystalline

Using a plasma spray torch, nanocrystalline γ-alumina powder has been synthesized in a reactor through oxidation of micron-size aluminum metal powder by in-flight thermal plasma processing. The synthesized particles were characterized by X-ray diffraction (XRD) and field emission transmission electron microscopy (FE-TEM). The particle size was in the range of ~7 to ~56 nm and spherical in shape. Furthermore the nonlinear refractive and absorptive indices of the sample under various intensities using Z-scan and moiré deflectometry techniques by a CW He-Ne laser at 632.8 nm wavelength were measured