Method for the fabrication of high-efficiency small-period diffraction gratings

A method was developed for the fabrication of high-efficiency diffraction gratings with an asymmetric line profile and a period of 0.4–1.2 µ over an area of 20 cm². The gratings were made by ion etching of the substrate through a photoresist mask produced by a holographic method. The diffraction efficiency of these gratings reached 82.5% in the first negative order in an autocollimation configuration.