Application of RZ-scan technique for investigation of nonlinear refraction of sapphire doped with Ag, Cu, and Au nanoparticles

Abstract

The results of investigation of the nonlinear refraction of sapphire doped by Ag, Cu, and Au nanoparticles using the reflection Z-scan technique are presented. The real parts of the third-order nonlinear susceptibility of Ag:Al 2O 3, Au:Al 2O 3, and Cu:Al 2O 3 were measured using the fundamental wavelength of Nd:YAG laser radiation ( λ = 1064 nm, t = 55ps). It was shown that the Ag:Al 2O 3 possessed by self-focusing properties ( n 2 = 1.8 × 10 −11 cm 2 W −1), whereas the Au:Al 2O 3 and Cu:Al 2O 3 showed the self-defocusing properties ( n 2 = −1.46 × 10 −10 and −1.7 × 10 −11 cm 2 W −1, respectively). The real part of third-order nonlinear susceptibility of Au:Al 2O 3 was measured to be 10 −8 esu. The mechanisms of nonlinear refraction are discussed.