Heating processes in plasmonic resonances: a non-linear temperature dependent permittivity model

Heating processes in plasmonics are essential every time the interaction with electromagnetic fields induces dissipation within metallic nanostructures. In particular the capability to predict the final temperature reached by a system (e.g. an ensemble of nanoparticles within a host medium) can be crucial when dealing with electronic, medical or chemical applications. Here we present a dispersive model of the dielectric function of a metallic medium which depends on temperature. Since temperature, in turn, depends on the intensity of the electromagnetic source and on the optical response of the medium itself, the model expresses non-linearity features. The model, which does not require any fitting parameter, can be utilized whenever the impact of temperature on the optical response of a system needs to be clarified and/ or when non-linearities might play a major role.