Electromagnetically induced transparency in a strongly coupled orthogonal polarization insensitive planar terahertz metamaterial

Abstract

Abstract We demonstrate experimentally and numerically the electromagnetic induced transparency (EIT) effect in a strongly coupled planar terahertz metamaterial. The circular shaped four-arcs geometry combined cross resonators ensures that polarization insensitive response of the EIT for the orthogonal polarization incident terahertz. The EIT response can be varied by changing the gap between the arc and cross shaped resonators. The field profiles indicate a strong coupling between the resonators leading to the EIT effect. In order to understand the underlying physical mechanism, we have employed a coupled harmonic oscillator model which suggests increase in coupling when the distance between resonators is reduced. Terahertz time domain spectroscopy of the fabricated samples with same shape and sizes of the simulated structures verify the numerical findings. Our study with symmetric and easy to fabricate planar metasurface can pave the way for design and construction of terahertz photonic components such as optical switches, slow light devices, etc.