Ion-beam etching technology in the production of optical elements

摘要

This paper discusses the results of the practical use of ion-beam etching (IBE) to fabricate optical elements with surface microrelief. It is shown that IBE can be used for asymmetrization of a sinusoidal line profile of relief holographic diffraction gratings (HDGs) formed in a photoresist layer. The result is to obtain HDGs whose diffraction efficiency (DE) maximum is displaced toward shorter wavelengths. The DEs of such HDGs are close to those of ruled gratings. In order to increase the DE of ruled diffraction gratings, IBE is used to correct the profile of rulings fabricated in an aluminum layer. The resulting DEs are close to the theoretical values. The optimum values found for the controlling parameters make it possible to fabricate the elements of an intracavity laser shutter, a phase-contrast ring for microoptics, kinoform optical elements, etc. with high accuracy in the depth of the rectangular microprofile and without degrading the initial microroughness.