Optothermal Modeling of Plasmonic Nanofocusing Structures With Nonlocal Optical Response and Ballistic Heat Transport

Abstract

Nanoscale optical energy focusing using plasmonic structures is crucial for many applications, such as imaging and lithography. Thermal management for these nanostructures is of great importance to maintain their reliabilities but has not been investigated extensively yet, especially when the strong nonlocalities present in the nanostructures. Here, we report a multiphysics model to study the coupled optical and thermal responses of plasmonic nanofocusing structures. We applied the hydrodynamic Drude model to describe the nonlocality in the optical response and derived ballistic–diffusive equations for both electrons and phonons to model the nonlocal thermal transport. Strong nonlocal optothermal responses were observed.