Optical transparency by detuned electrical dipoles

Abstract

We demonstrate that optical transparency can be realized with plasmonic metamaterials using unit cells consisting of detuned electrical dipoles (DED), thereby mimicking the dressed-state picture of the electromagnetically induced transparency (EIT) in atomic physics. Theoretically analyzing the DED cells with two and three different silver ellipsoids, we show the possibility of reaching a ≥10 times decrease in group velocity and a propagation loss of ≤1 dB per cell within the optical wavelength range of 625-640 nm. Similar configurations are realized with lithographically fabricated gold nanorods placed on a glass substrate and subsequently covered with a ∼15-μm-thick polymer layer, featuring EIT-like transmission spectra with transparency windows at wavelengths of ∼850 nm.