Mistura não linear por duas ondas utilizando luz estruturada

Abstract

The modification of optical properties due to light-matter interaction is object of study of Nonlinear Optics. The possibility of the polarization of a material to respond with powers of the applied field’s amplitude gives rise to many physical phenomena of great scientific and technological interests. Together with it, structuring light, meaning the application of custom light fields, allow us to study it in very particular systems. In this dissertation, we investigate the structured light interaction with a nonlinear media in the context of two-wave mixing. Initially we present the nonlinear mixture of Laguerre-Gaussian (LG) beams of null radial order and arbitrary orbital angular momentum. It is observed that the nonlinear media acts as a coupler between different degrees of freedom of this particular structured beam, enabling the relation between the topological charge of the incoming beams with the radial orders of the generated beam through its nonlinear interaction with matter. Next, as a first set of results of this dissertation, we extend this type of mixture by considering LG beams of non-null radial order and discuss about its implications. Later we show the mixture of LG beams carrying fractional topological charge and, with it, showing the birth of a vortex and radial orders in the generated beam. Subsequently, using a superposition of Hermite-Gaussian (HG) modes as initial beams, we perform the inverse process. We specify the desired output beam that results from the nonlinear mixture and find the incoming beams mode superposition. In this way, we were able to perform optical mode conversion of different paraxial basis. Lastly, we perform a study of the two-wave nonlinear mixture of Ince-Gaussian (IG) modes, obtaining its selection rule and analyzing the transition between the mixture of LG and HG modes, that reveals itself as particular cases of the modes here considered.