Diffractive Focusing Structures for Broadband Application in thz Range

Abstract

Small thickness of diffractive structures results in low absorption and therefore makes them ideal for THz beam shaping. However, diffractive optics suffers from high chromatic aberrations, which can be suppressed by using different designing method like high order kinoforms. In this paper spherical lenses and structures with increased depth of focus, coded as kinoforms of first and second order, are analyzed for chromatic aberration reduction.