Sensibilidad al entorno dieléctrico de las propiedades plasmónicas del oro

Abstract

In this work, a study of the sensitivity to the dielectric environment of plasmonic resonances in gold films is presented. The system consists of a 38 nm thick gold film grown on a glass substrate that is illuminated under conditions of total internal reflection (Kretschmann configuration) with a 533 nm laser. A layer of silicon oxide (SiO) of variable thickness that simulates the changes in the dielectric environment and allows to evaluate the principle of reflectometric detection is considered on the system. The problem of propagation of light in this system is treated with the transfer matrix method, with which the reflectance of the structure is calculated. The analysis described here consists of calculating the evolution of the angular dependence of the reflectance of the system as a function of the SiO thickness, besides the theoretical results are contrasted with experimental results and allow to obtain the limit of detection of the structure. Finally, a sensitivity model is suggested to explain the angular shift of the reflectance in this system and thus quantify the sensitivity of the structure.