Multiphysics simulations of adaptive metasurfaces at the meta-atom length scale

Nanophotonics

article

Sebastian Meyer¹  Zhi Yang Tan¹  Dmitry N. Chigrin¹ 

[1] I. Physikalisches Institut (1A), RWTH Aachen University;DWI – Leibniz Institute for Interactive Materials

关键词: phase change materials;    multiphysics simulations;    phase field model;    active metamaterials;    perfect absorber;   

DOI  :  10.1515/nanoph-2019-0458

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Adaptive metasurfaces (MSs) provide immense control over the phase, amplitude and propagation direction of electromagnetic waves. Adopting phase-change materials (PCMs) as an adaptive medium allows us to tune functionality of MSs at the meta-atom length scale providing full control over MS (re-)programmability. Recent experimental progress in the local switching of PCM-based MSs promises to revolutionize adaptive photonics. Novel possibilities open new challenges, one of which is a necessity to understand and be able to predict the phase transition behavior at the sub-micrometer scale. A meta-atom can be switched by a local deposition of heat using optical or electrical pulses. The deposited energy is strongly inhomogeneous and the resulting phase transition is spatially non-uniform. The drastic change of the material properties during the phase transition leads to time-dependent changes in the absorption rate and heat conduction near the meta-atom. These necessitate a self-consistent treatment of electromagnetic, thermal and phase transition processes. Here, a self-consistent multiphysics description of an optically induced phase transition in MSs is reported. The developed model is used to analyze local tuning of a perfect absorber. A detailed understanding of the phase transition at the meta-atom length scale will enable a purposeful design of programmable adaptive MSs.

【 授权许可】

CC BY