Optimization of enhanced terahertz transmission through arrays of subwavelength apertures

Abstract

A detailed study of enhanced transmission of terahertz (THz) radiation through arrays of subwavelength apertures structured in n-type silicon is presented. The enhancement is attributed to the resonant tunneling of surface-plasmon polaritons (SPP's) that can be excited at THz wavelengths in doped semiconductors. We investigate the dependence of the transmission as a function of aperture size and sample thickness. The transmission increases significantly as the aperture size is augmented and as the array thickness is reduced. The data confirm the tunneling character of the SPP phenomenon. Transmission efficiencies larger than unity for aperture sizes well below the cutoff wavelength are achieved.