Simulations of silicon diractive lenses for terahertz frequencies have been performed using a Fraunhofer wave propagationmodel to show how the lens eciency can be aected by dierent fabrication defects. A general model is presented to illustrate theope...
Simulations of silicon diractive lenses for terahertz frequencies have been performed using a Fraunhofer wave propagationmodel to show how the lens eciency can be aected by dierent fabrication defects. A general model is presented to illustrate theoperating bounds which must be adhered to when fabricating a lens using a multiple level process. From these simulations it ispossible to ascertain for a specic lens design with known processing inaccuracies what level of design complexity will gain the mostbenet. It is shown that for a 1 THz lens fabricated using an eight level process the lens eciency is reduced by less than 20% forrealistic values of etch non-uniformity, inter-level misalignment and surface roughness.