Cavity Induced Tunable Extraordinary Transmission: A Unique Way of Funneling Light through Subwavelength Apertures

Abstract

Extraordinary transmission through subwavelength metallic apertures has been extensively studied and demonstrated. At resonance, the coupling between surface plasmons on both surfaces of the metallic film tunnels the photon from the one side to the other through the subwavelength aperture with small transmission efficiency based on the metals dielectric parameters and aperture geometrical dimensions. Here, we report a completely different form of extraordinary transmission, where the two subwavelength complementary apertures when coupled with an optical cavity induce about 100% extraordinary transmission far away from the natural plasmon resonance of the constituent metallic apertures. Such unique cavity phase driven plasmon resonance enables tuning of the extraordinary transmission band across wide spectral range unlike previously reported geometry driven extraordinary transmission.