Fabrication and replication of continuous-relief DOEs

Progress in the fabrication of continuous-relief Diffractive Optical Elements (DOEs) by laser beam writing in photoresist followed by replication into epoxy or polymer materials is described. The technology enables a wide range of microoptical elements to be fabricated, including kinoform elements and general microrelief phase structures for a variety of applications in optical systems. Replicas are produced in polymer foil, as well as in thin epoxy films on glass substrates, using Ni shims generated from the recorded microrelief structures. The continuous relief microoptical elements offer an interesting alternative to multilevel `binary´ optical elements, in many cases with improved performance and lower cost