Temperature effect on optical properties of colloidal ZnO nanoparticles

In this paper, we investigated the temperature dependence and optical contrast variations of a nonlinear optical material. The experiments were performed using the close and open aperture z-scan technique using a CW laser beam at 632.8 nm. The nonlinear optical behavior is attributed to thermo-optical effect. The absorption variation as function of temperature is studied. The linear absorption variation induces changes in nonlinear refraction. The nonlinear optical properties of the samples reduce when the temperature increases.

► Investigation of temperature effect on linear and nonlinear optical properties of colloidal ZnO nanoparticles in different solvents.
► Theoretical study of temperature effect on absorption coefficient of nanoparticle colloidal solvents using Mie theory.
► Demonstration that using a solvent with higher cubic expansion coefficient and refraction index (such as benzene) in order to obtain much more thermo-optical nonlinearity.
► Suggesting that cooling the sample causes much more optical nonlinearity in colloidal ZnO nanoparticles.