Linear and nonlinear optical properties of highly concentrated gold nanoparticles

Linear and nonlinear (NL) optical properties of composite materials containing high concentration of gold nanoparticles (NPs) were studied using the Maxwell–Garnett model and the degenerated electron gas model. High values of the linear refraction index of the composite, NL shift of the plasmon resonance peak and reversal sign of the real and imaginary parts of the NL third-order susceptibility were observed. Figures of merit for photonic devices were calculated and fulfilled depending of the filling factor and NPs size.