Tunable subwavelength terahertz plasmon-induced transparency in the InSb slot waveguide side-coupled with two stub resonators

We numerically investigated the realization of electromagnetically induced transparency (EIT) at the terahertz (THz) region in an InSb slot waveguide side-coupled with two stub resonators. The mechanism of the EIT phenomenon is theoretically analyzed and numerically studied by using coupled mode theory and the finite element method, respectively, and the theoretical results are in good agreement with the simulation results. The simulation results reveal that the EIT-like response is strongly dependent on the coupling separation between the two stub resonators, and we derived the best separation between the two stub resonators to get the most obvious EIT-like spectra. More importantly, the central wavelength of the EIT-like spectra can be actively controlled by tuning the temperature. This plasmonic waveguide system may have potential applications for ultracompact THz integrated circuits, such as thermo-tunable filters, THz switching, slow-light components, and THz sensitive sensors. (C) 2015 Optical Society of America