Field enhancement with classical electromagnetically induced transparency

Artikel i vetenskaplig tidskrift, 2015

A key challenge in the design of tunable and nonlinear metamaterials is creating large local electromagnetic fields to enhance the nonlinear interaction. An attractive way to achieve local field enhancement is the use of metamaterials with dark resonators, i.e., with meta-atoms that do not directly couple to the external field. Such metamaterials exhibit a scattering response that is similar to what is observed for electromagnetically induced transparency (EIT): they combine large group delay with low absorption at the same frequency. Classical EIT metamaterials are interesting for nonlinear metamaterials because of the large field enhancement due to the lack of radiation loss in the dark element and for tunable metamaterials because of the high sensitivity of the resonance to the environment or a control signal. We discuss the design and modeling of EIT metamaterials and some early work on their applications to media with nonlinear/tunable response.