Polarized infrared emission using frequency selective surfaces.

An emission frequency selective surface, or eFSS, is made up of a periodic arrangement of resonant antenna structures above a ground plane. By exploiting the coupling and symmetry properties of an eFSS, it is possible to introduce polarization sensitive thermal emission and, subsequently, coherent emission. Two surfaces are considered: a linearly polarized emission surface and a circularly polarized emission surface. The linearly polarized surface consisted of an array of dipole elements and measurements demonstrate these surfaces can be fabricated into high polarization contrast patterns. The circularly polarized surface required the use of an asymmetrical tripole element to maintain coherence between orthogonal current modes and introduce the necessary phase delay to realize circularly polarized radiation.