Plasmonic analog of electromagnetically induced transparency in planar metamaterials: manipulation and applications.

In this article, we have investigated an analog of electromagnetically induced transparency (EIT) in planar metamaterials by a metallic regular triangle (RT) embedded in split ring (SR) nanostructure. It is demonstrated that, depending on the different coupling ways between the RT and the SR, the EIT-like spectral response can be actively modulated by simply adjusting the incident light polarization angle. Based on this observation, an on-to-off active modulation of the EIT-like transparency window can be realized, and it can serve as the base for an optical switching with the switching efficiency exceeding 95%. The size of the RT finely controls the coupling strength between the RT and the SR. It is shown that the EIT-like transparency window can be enhanced or suppressed by adjusting the size of the RT, which shows the big modulation to the EIT-like spectral response. Furthermore, the transmission spectra show potential applications in sensing due to high sensitivity of about 600 nm/RIU with figure of merit exceeding 36 to the surrounding environment. [ABSTRACT FROM AUTHOR]