Electromagnetically induced transparency in a planar complementary metamaterial and its sensing performance

In this paper, a classical analogue of electromagnetically induced transparency (EIT) is demonstrated theoretically in a planar complementary metamaterial consisting of a short slot as bright resonator and a long slot as dark resonator in a thin sliver film. A sharp and narrow reflectance transparency window is observed within a broad absorption spectrum at optical frequencies when structural symmetry is broken. Furthermore, the transparency peak exhibits highly sensitive response to the refractive index of surrounding medium, ensuring our proposed metamaterial as an excellent plasmonic sensor. The dependence of figure of merit (FOM) on structural asymmetry is investigated numerically to optimize the sensing performance of the EIT-based sensor.