Investigating the linear and nonlinear optical properties of Al alloyed Ni nanofilms in the cw regime

Abstract

In this research, we investigated the linear and nonlinear optical properties of Al alloyed Ni nanofilms prepared by e-beam evaporation on glass substrates. Thin layers of Ni and Al were deposited sequentially at room temperature on glass substrates. The intermixed layers revealed different structures of Ni and Al formations due to a spontaneous intermixing process with controlled stoichiometric ratios. The Maxwell–Garnett theory for the composite matrix formed by the Ni–Al​ inclusions and alloys was used to predict the complex dielectric functions of the fabricated films. Since Al is a trivalent element, the electron population density was enhanced near the Ni–Al atomic sites with an increase in the Al content. This enhancement boosted the nonlinear absorption in the alloyed films. The composite model was used to interpret this enhancement of the nonlinear optical behavior over pure Ni films. The results are discussed in relation to future applications.