Geometrical Effects of Split-ring Resonators on the Transmission of a Single-subwavelength Aperture

Since the transmission through a single-subwavelength aperture with a radius of r << lambda is proportional to (r/lambda)(4), where lambda is the wavelength of irradiation, the transmission may vanish according to Bethe's theory. Recently, it was proposed that this is not always true when a split-ring resonator (SRR) is coupled to the aperture. In order to elucidate the geometrical influences of SRRs on the transmission, we systematically investigated a series of SRR geometries, such as the relative positions of the inner and the outer splits, the tickness of SRR, the number of splits, and so forth. The finding should be beneficial for guiding and redirecting light in nanophotonic devices through metamaterial elements.