Inverse design of plasma metamaterial devices with realistic elements

TL;DR

This paper uses inverse design methods with realistic plasma elements to create microwave plasma metamaterial devices like waveguides and demultiplexers, considering practical factors such as collisionality and non-uniform density.

Contribution

It extends previous inverse design work by incorporating realistic plasma parameters and evaluates their impact on device performance and robustness.

Findings

Designed microwave waveguides and demultiplexers with realistic plasma elements.

Compared idealized and realistic element designs, showing practical feasibility.

Demonstrated device operation at ~10 GHz plasma frequency with ~1 GHz collision frequency.

Abstract

In an expansion of a previous study [1], we apply inverse design methods to produce two-dimensional plasma metamaterial devices with realistic plasma elements which incorporate quartz envelopes, collisionality (loss), non-uniform density profiles, and resistance to experimental error/perturbation. Backpropagated finite difference frequency domain simulations are used to design waveguides and demultiplexers operating under the transverse magnetic polarization. Optimal devices with realistic elements are compared to previous devices with idealized elements, and several parameter initialization schemes for the optimization algorithm are explored. Demultiplexing and waveguiding are demonstrated for microwave-regime devices composed of plasma elements with reasonable space-averaged plasma frequencies ~10 GHz and a collision frequency ~1 GHz, allowing for future in-situ training and experimental realization of these designs.