Electromagnetically Induced Transparency in Metamaterials Using Theory of Characteristic Modes

High sensitivity in sensors, large group delays for filters and slow light can be achieved by engineering electromagnetically induced transparency within a narrow electromagnetic spectrum. The induced transparency is due to the elimination of the effect of a medium caused by interaction between two resonant states often referred to as the bright and dark modes. Induced transparency are often attained by breaking the structural symmetry of metamaterials as this allows interaction between the two modes. In a case of a given excitation, there is a need to understand the behaviour of the various modes thus making the application of theory of characteristic modes relevant to this work. This paper presents an approach to obtain electromagnetically induced transparency for a given excitation using the theory of characteristic modes. It presents how electromagnetically induced transparency in a structure can be systematically engineered by determining which modes are responsible for its occurrence and how to excite these modes. In our example, EIT occurred at 36 GHz where there was an interaction between the bright and dark modes. This provides an insightful way for designing structures for electromagnetically induced transparency applications.