Tunable figure of merit for a negative-index metamaterial with a sandwich configuration

摘要

Metamaterials with a free-standing Ag–SU-8–Ag sandwich configuration, perforated with a periodic array ofncross-dipole apertures, are fabricated. The transmittance spectra of both experiment and simulation havenindicated the existence of two transmission bands in mid-IR frequencies. The high-frequency transmissionnpeak is the guided mode associated with the surface plasmon polariton (SPP), and its location strongly dependsnon the arm length of the cross-dipole. The lower-frequency transmission peak is proposed to be thenantisymmetric plasmon polariton mode, and its location hardly shifts as the size of the cross-dipole varies.nNumerical simulations indicate that, on increasing the arm length of the cross-dipole aperture, the coactionnof the electric dipole-like mode and the SPP-associated guided mode results in a better figure of merit.n© 2009 Optical Society of America