Directed by Dr. Alejandro Reyes Coronado (http://sistemas.fciencias.unam.mx/~coronado/)
Master thesis for obtaining the title of Master in Science (Physics)
Dissertation at the Posgrado en Ciencias Físicas, National Autonomous University of Mexico (PCF-UNAM)
Plasmonic metasurfaces, metallic nanostructures supported on a substrate, have been used as alternatives for biosensing due to their low-cost and easy-to-use features, and due to their light enhancement and confinement capacity. In common biosensing techniques, a liquid flows over the substrate, where the nanostructure is located, so there is a detachment risk. Therefore, a partial embedding of the nanostructure in the substrate is desirable, which modifies its optical response under ideal conditions. In this thesis, it is studied the optical response of a single spherical gold nanoparticle of radius 12.5 nm, suited for biosensing-aimed-metasurfaces, when the nanosphere is partially embedded in between an air matrix and glass substrate, both which form a flat interface, and illuminated by an electromagnetic plane wave with wavelengths in the optical range, considering two states of polarization as well as different angles of incidence. The optical properties of the partially embedded nanosphere, that is, the scattering, absorption and extinction cross sections and the induced electric field in the near and far-field regimes, are calculated by means of the Finite Element Method and compared with the analytical solutions of two limiting cases: a nanosphere embedded in an infinite matrix of air, and in an infinite matrix of glass. Based on the obtained numerical results, it was determined optimal configurations for biosensing with a disordered metasurface of partially embedded nanosphere of radius 12.5 nm in the diluted regime.
- Codes and inkscape files for each graph and diagram shown in the thesis and the presentation.
- Aside form the Finite Element calculations performed in Comsol Multiphysics, all codes for the Mie Theory results, as well as for any graph shown in the Thesis can be found in here.
- The codes for the graphs are in both Mathematica (.nb) and in Jupyter (.ipynb) Notebooks.
- To run the Mie Theory related codes and employ the size-correctred dielectric function for gold nanospheres you need to use the (soon to have a proper documentation) Mie Theory for Mathematica packege found in here.
- The complete thesis tex-files, whose main file is tesis.tex
- The complete presentation tex-files, whose main file is presentation.tex