In this study, cobalt oxide (CoO) thin films were prepared by pulsed-laser deposition method using a pulsed Nd:YAG laser. The surface morphology of the prepared CoO thin films was uniform with an increase in grain size and the presence of distinctive shapes. The results of the nonlinear optics study demonstrated that the CoO thin films have a saturated nonlinear absorption coefficient, a negative refraction index (self-defocusing), moreover the calculation of third order nonlinearity susceptibility. Thus, CoO thin films possess good properties for the applications of nonlinear optics.
