Adjustable phase resonances in a compound metallic grating with perpendicular cuts

We propose a compound metallic grating with perpendicular cuts in each slit and investigate its optical transmission property theoretically. The odd and even waveguide modes exhibit different behaviors when the cuts are set asymmetrically in the slits. Particularly, it is shown that the transmission dips of transmission spectrum for this compound periodic structure can be realized alternately by shifting the position of cuts in the slit. The effect of cut size on the phase resonances in the proposed metallic grating is also identified, and the underlying physics is discussed by the simulated field and phase maps. (C) 2010 Optical Society of America