Controlling the transmission resonance lineshape of a single subwavelength aperture

Recent demonstrations have shown that by creating a periodic surface corrugation about a single subwavelength aperture, the transmission can be enhanced at wavelengths related to the periodicity. We demonstrate that by varying the phase of the surface corrugation relative to the single subwavelength aperture, dramatic variations can be made in the transmission resonance lineshape at THz frequencies, ranging from transmission enhancement to transmission suppression. This finding is particularly surprising, since the nearly exclusive focus of published work has been on understanding and optimizing the enhancement process in these and associated structures. We present a simple model that qualitatively explains our observations. This represents, we believe, a first step in fully controlling the spectral transmission properties of these structures.