Infrared plasmonic refractive index-sensitive nanosensor based on electromagnetically induced transparency of waveguide resonator systems

We propose an infrared plasmonic refractive index-sensitive nanosensor based on the electromagnetically induced transparency (EIT) of waveguide resonator systems. The structure consists of one tooth-shaped cavity as well as the bus and stub metal–insulator–metal waveguides. By adjusting the structural geometry, it is demonstrated that the controllable transmission of EIT response can be obtained with the coupled-mode theory and the finite-difference-time-domain simulations. It is found that the transmission spectra dip at the spectra can be strongly controlled by changing the refractive index filled in the stub waveguide. The calculated results show that the sensitivity, full width at half-maximum and figure of merit of plasmonic nanosensor are 733 nm/RIU, 24.11 nm and 695, respectively. With the compact structure, the nanosensor may have great potential to be used in the field of integrated optoelectronics.