A modified Gerchberg-Saxton algorithm for design diffractive optical elements generating light distributions with submicron features

Abstract

The well-known Gerchberg-Saxton (GS) algorithm allows the reconstruction of an unknown wave front from known intensity distributions on a few planes of an optical system, for example, in the input plane and the focal plane. It is also the method of choice for the production of computer-generated holograms and calculation of the transmission function of diffractive optical elements (DOEs) generating so-called structured laser beams. Such ‘unconventional’ laser beams have unique features of an amplitude/phase/polarisation distribution, significantly extending opportunities for application of laser optics in many fields of modern science. Here, we propose a new modification of the basic GS algorithm that can be used to calculate a pure-phase transmission function of DOEs which generate complex intensity distributions with submicron features. DOEs designed in this way can be used in the field of laser fabrication of nano- and micropatterns, allowing the high-performance single-step fabrication of nanostructures for real applications in nanophotonics and optical manipulation.