In this paper we discuss the properties of optical elements fabricated by holographically recording an ultra-high spatial-frequency pattern in a photoresist mask followed by reactive ion etching to transfer this pattern into the surface of a quartz substrate. Such optical elements are environmentally durable, potentially easy to replicate, and exhibit diffraction efficiencies in excess of 85%. In addition, two other properties are reported for the first time. Such elements at normal (0°) incidence are antireflective, with broadband reflection coefficients as low as 0.035%. Also, the elements exhibit artificially produced birefringence making them useful as wave plates. These results may be particularly significant in the UV and IR, where damage-resistant antireflection coatings and transparent birefringent materials may not exist.
Rolf C. Enger and Steven K. Case, "Optical elements with ultrahigh spatial-frequency surface corrugations," Appl. Opt. 22, 3220-3228 (1983)