Enhanced Optical Transmission of a Continuous Metal Film With Double Metal Cylinder Arrays

A novel metal structure that integrates a continuous metal film and double deep subwavelength metal cylinder arrays standing on both surfaces is proposed. Near-perfect optical transmission is observed in this metal film structure due to the cooperative effects of the double deep subwavelength plasmonic arrays which, respectively, act as the efficient light input and output couplers. High tunability of transmission behaviors is demonstrated by varying the geometry parameters of the cylinder arrays and the surrounding refractive index. Such a high transparent metal film structure with an ultra-small geometry size (gap distance $G<$ resonant wavelength $(\lambda )$ /160, period $P< \lambda /10$ ) could facilitate numerous important applications in highly integrated plasmonic filters, sensors, and optoelectronic circuits.