Overcoming losses with gain in a negative refractive index metamaterial

TL;DR

This paper demonstrates that incorporating gain media into a negative refractive index metamaterial can counteract inherent losses, leading to amplification and improved performance at specific frequencies.

Contribution

It introduces a full-vectorial Maxwell-Bloch approach to show how optically pumped gain can induce amplification in fishnet metamaterials.

Findings

Gain placement results in a frequency band with amplification.

Both real and imaginary parts of the refractive index become negative.

Figure of merit diverges at two frequency points.

Abstract

On the basis of a full-vectorial three-dimensional Maxwell-Bloch approach we investigate the possibility of using gain to overcome losses in a negative refractive index fishnet metamaterial. We show that appropriate placing of optically pumped laser dyes (gain) into the metamaterial structure results in a frequency band where the nonbianisotropic metamaterial becomes amplifying. In that region both the real and the imaginary part of the effective refractive index become simultaneously negative and the figure of merit diverges at two distinct frequency points.