Linear and nonlinear optical properties of Al2O3/Y2O3 nanolaminates fabricated by atomic layer deposition

Abstract

The structure and composition of nanocomposites constitute design parameters that can be manipulated to get control over their linear and nonlinear optical response. In this work, we report the linear and nonlinear optical properties of samples consisting of multiple Al2O3/Y2O3 bilayers with a total thickness of ∼ 500 nm, fabricated through the atomic layer deposition technique onto Si and SiO2 substrates. Fabrication of the multiple layer configurations was made for four Y2O3 layer thicknesses, while maintaining a constant Al2O3 layer thickness for all the samples fabricated. Physical and chemical characterization of the samples produced was conducted by optical ellipsometry, transmission electron microscopy and XRD. Moreover, their third-order nonlinear optical properties were studied through the z-scan technique with 100 fs pulses at 800 nm from a Ti:Sapphire laser, allowing the resolution of the refractive and absorptive contributions to the response. The nonlinear parameters extracted from the experiments are discussed in terms of the fabrication thickness of the selected materials. Additionally, figures of merit relevant for the possible application of these materials in optical processing system are calculated and discussed.