Abstract

The diffractive optics community has embraced the lithographic methods used in the electronics industry¹. Typically, binary transmission masks are used to expose resist and produce stepped structures which approximate the ideal, continuous profiles. Since these profiles are approximations of the ideal, continuous profiles, the diffraction efficiency is less than 100%: in theory, a four-level DOE has a first-order efficiency of 81%; an 8-level DOE, 95%¹. Although the efficiency can be increased by increasing the number of levels and computer-based optimization, the process is limited by the resolutions of the binary masks and of the mask registration to the substrate.

© 1996 Optical Society of America