Focusing of Terahertz Waves onto Micron-sized Slits Grown on ZnTe and GaP Substrates

Abstract

We report on terahertz focusing through rectangular slit; apertures on thin metal film by using terahertz time domain spectroscopy both in the far- and in the near-field. Our experiments show, that far-field perfect, transmission is maintained in the rectangular slit array even as the aperture coverage decreases. Near-field imaging supports the field enhancement in the single rectangular aperture indeed occurring at a frequency equal to the fundamental shape resonance frequency.