Broad-band polarization-independent total absorption of electromagnetic waves by an overdense plasma

TL;DR

This paper demonstrates a method for achieving polarization-independent broad-band electromagnetic wave absorption in overdense plasma through surface plasmon-polariton excitation, using a 2D diffraction grating and specific incident angles, with experimental validation.

Contribution

It introduces a novel approach combining a 2D diffraction grating and incident angle to enable broadband, polarization-independent absorption in overdense plasma, confirmed by direct SPP detection.

Findings

Successful experimental detection of surface plasmon-polaritons in plasma.

Achieved polarization-independent broad-band absorption.

Validated theoretical model with experimental results.

Abstract

We have shown both experimentally and theoretically that polarization-independent broad-band absorption of electromagnetic waves by an overdense plasma, caused by surface plasmon-polaritons (SPP) excitation, can be achieved due to combination of two factors: a non-zero angle of incidence and a two-dimensional circular diffraction grating placed at a properly chosen distance in front of the plasma boundary. Direct detection of SPP has been achieved for the first time using a miniature antenna imbedded in the plasma.