Periodically Structured Metal Surface Optical Characteristics Of The Dielectric Film

Since 1998, T.W. Ebbesen et al. reported the observation of enhanced extraordinary transmission of light through nano hole arrays in an optically opaque metallic film. Many scientists paid their attentions on this phenomena and the study on the transmission behavior works in sub-wavelength optics. 1D grating is the most typical structure in various aperture structures,Besides,the extraordinary transmission phenomena makes sub-wavelength 1D grating have broad potential in solar and developing equipments. The transmission characteristics though Sub-wavelength metallic gratings is simulated by FDTD,based on the light guided theory and index effect method, a number of innovative research results are as follow:[1]For how to achieve the extraordinary transmission of one- dimensional metallic gratings with sub-wavelength slits, the transmission distribution of transverse electric wave (TE) through one-dimensional metallic gratings with sub-wavelength slits adding dielectric in different locations has been simulated by the FDTD (finite difference time domain) method, the result which is the relations between the refractive index of dielectric and the transmission efficiency is elicited from simulation shows that the extraordinary transmission can be produced at several special wavelengths. Then, a new theory named the guided-mode-like resonance theory is put forward based on the guided-mode resonance theory, which is suited well for the extraordinary transmission under the TE-polarized wave exciting, and it can be concluded that the guided-mode-like is the main reason for the extraordinary transmission of TE-polarized wave. Therefore, the new theory can explain the problems which can't be explained by the traditional theory. In a word, the guided-mode resonance theory reveals the physical nature of the extraordinary transmission phenomenon which provides a theoretical basis for the further study of the extraordinary transmission phenomenon.[2] Based on the guided-mode-like resonance theory which is the main reason for the first peak and the second peak, from the Maxwell's equations, we can sure the Fabry-Perot (F-P) resonance is the main reasons to produce the third peak by the effective index method. In a word, the guided-mode resonance theory and the F-P-like resonance reveal the physical nature of the extraordinary transmission phenomenon which provides a complete theoretical basis for the further study of the extraordinary transmission phenomenon of TE-polarized wave.