Inverse design and experimental realization of plasma metamaterials

TL;DR

This paper demonstrates the use of inverse design methods to create and experimentally realize plasma metamaterials capable of beam steering and demultiplexing, highlighting the advantages of computational optimization in device fabrication.

Contribution

It introduces a novel inverse design approach for plasma metamaterials, integrating simulations and automatic differentiation to optimize device performance before experimental realization.

Findings

Optimized plasma densities enable effective beam steering.

Experimental results closely match simulations, validating the design approach.

Inverse design outperforms human-designed alternatives in certain metrics.

Abstract

We apply inverse design methods to produce two-dimensional triangular-lattice plasma metamaterial (PMM) devices which are then constructed and demonstrated experimentally. Finite difference frequency domain simulations are used along with forward-mode automatic differentiation to optimize the plasma densities of each of the plasma elements in the PMM to perform beam steering and demultiplexing under transverse magnetic polarization. The optimal device parameters are then used to assign plasma density values to elements that make up an experimental version of the device. Device performance is evaluated against both the simulated results and human-designed alternatives, showing the benefits and disadvantages of in-silico inverse design and paving the way for future fully in-situ optimization.