Enhanced transmission mediated by guided resonances in metallic gratings coated with dielectric layers.
Transmission properties of metallic gratings coated symmetrically with a dielectric layer on both sides are studied theoretically. For subwavelength narrow slits, besides cavity resonances in slits and surface plasmon-polaritons, a new kind of mechanisms for enhanced transmission in coated metallic gratings, namely, guided resonances in the dielectric coating layers, is found. Transmission peaks mediated by guided resonances are found to be much sharper than those mediated by cavity or surface plasmon-polariton resonances.
Surface Physics Laboratory and Department of Physics, Fudan University, Shanghai 200433, People's Republic of China.
Fengqin
F
Wu
Dezhuan
D
Han
Xin
X
Li
Xiaohan
X
Liu
Jian
J
Zi
D004560:Electricity; D008280:Magnetics; D008670:Metals / Q000737:chemistry*; D055095:Optics and Photonics; D012834:Silver; D013057:Spectrum Analysis
D008670:Metals; D012834:Silver