Extinction Efficiency and Electromagnetic Fields of Isolated and Coupled Core-Shell Nanoparticles
The study of metallic nanoparticles fed by optical fields has great interest in nanophotonics, for example in sensing devices. This paper presents a theoretical study of the interaction between electromagnetic waves and gold nanostructures with spherical geometries, which have a thin dielectric layer of silica. It is considered that the particle’s size is much smaller than the operating wavelength, characterizing the Rayleigh scattering regime. Using an analytical model through the Laplace equation, the interaction between an oscillating uniform electric field and a core-shell nanosphere is presented. Then, using a numerical model, the scattering of two interacting core-shell nanospheres is also analyzed, as a function of the distance between them. For the isolated particle case, the efficiency parameters of scattering, absorption and extinction cross sections were calculated and compared with experimental data of absorbance curves. The results were obtained in the range of wavelengths from 450nm to 750nm. Some conclusions about the range of validity of the model in functions of the particle’s dimensions are presented.
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).