Dielectric hole lattice for terahertz diffractive optics with high transmission

A dielectric hole lattice is proposed for creating diffractive optics in the terahertz range. An array of sub-wavelength air-holes in a dielectric material gives rise to an artificial dielectric, with refractive index depending on hole radius. The design uses low-loss dielectric materials, and exploits a half-wavelength etalon effect to minimise reflection, leading to near-perfect transmission. A potential application is a zone plate to create high gain antennas for use in future terahertz communications links.