Microstructured tungsten surfaces as selective emitters

Abstract

This paper presents the optical properties of periodic microstructured tungsten surfaces used as selective emitter materials. Theoretical calculations are done using rigorous diffraction theory, and the influence of the grating period and the grating depth on the absorptance of tungsten gratings is investigated. Microstructured tungsten surfaces are fabricated using a holographic process to produce a photoresist mask. Subsequently a reactive ion etching process or a chemical etching process transfers the structure into tungsten. The absorptance of the tungsten gratings is measured and compared with the theoretical predictions of the rigorous diffraction theory.