Electro-thermal modelling for plasmonic structures in the TLM method

Ahmed Elkalsh,Trevor M Benson,Phillip D Sewell,Ana Vukovic

doi:10.1007/s11082-016-0542-x

Abstract

This paper presents a coupled electromagnetic-thermal model for modelling temperature evolution in nano-size plasmonic heat sources. Both electromagnetic and thermal models are based on the Transmission Line Modelling (TLM) method and are coupled through a nonlinear and dispersive plasma material model. The stability and accuracy of the coupled EM-thermal model is analysed in the context of a nano-tip plasmonic heat source example.

Highlights

Plasmonics waveguides and devices have attracted large attention in the research community in the past decade due to the ability of a metallic-dielectric interface to support surface-plasmon (SP) modes at optical frequencies
This paper presents a coupled electromagnetic-thermal model for modelling temperature evolution in nano-size plasmonic heat sources
The multi-physics nature of optical heating is in this paper described as follows: The electromagnetic Transmission Line Modelling (TLM) model is used to model electromagnetic scattering of the optical wave in the plasmonic waveguide

Summary

Introduction

Plasmonics waveguides and devices have attracted large attention in the research community in the past decade due to the ability of a metallic-dielectric interface to support surface-plasmon (SP) modes at optical frequencies. This is schematically shown, where cumulative power loss of the EM model is used to excite the thermal simulation and where EM and thermal simulations are performed separately, generally using different time steps (DtEM = Dtth) for the same real time Tmax This is clearly inadequate if temporal sources are considered and in scenarios where the material parameters are frequency dependent as is the case of a metal at optical frequencies. It is clear that the choice of the coupling interval which determines the thermal time steps would affect the stability, self-consistency and accuracy of the overall coupling method

The model

The thermal model

Zs þ Is ð12Þ

Results

Conclusion