Here we present results from key aspects of our interest in using micromachined devices in the THz region. First, our early work on making filters from rods of gold-coated SU8 is described. Pass (up to 97%) and stop bands can be observed which are theoretically underpinned by both FDTD and complex band structure simulations. Second, there is a discussion of how THz radiation passes through two-dimensional periodic arrays of subwavelength apertures. In particular, the geometry of the arrays has been studied with time-domain spectroscopy. A time-of-flight model is presented which can be used to provide insight into the operation of these arrays and has implications for the optimum design of THz plasmonic sensors. Finally, we report the THz ‘super’ extraordinary transmission properties of an optimised hybrid subwavelength aperture array, surrounded by subwavelength grooves.
Influence of aperture shape on the transmission properties of a periodic array of subwavelength apertures