Diffractive optical elements for generation and transformation of structured laser beams

Abstract

In this paper, we consider methods of design and manufacture of diffractive optical elements (DOEs), generating socalled structured laser beams with predetermined amplitude/phase/polarisation distributions and perform transformation of those laser beams. Diffraction optics makes it possible to implement generation and control of the structured laser beams via single DOE and their combinations. We demonstrate several traditional methods that can be used to calculate a pure-phase transmission function of DOEs, both iterative and non-iterative. In addition, different technological processes for the manufacture of DOEs are used, including direct laser writing in thin films and lithography combined with plasma etching. The structured laser beams generated using DOEs provide new opportunities for large-scale highrate laser fabrication of nano- and microscale functional elements, as well as for the laser manipulation of microscale objects. The use of the structured laser beams in these applications (for example, radially/azimuthally polarised laser beams, optical vortex beams or beams with complex-shape transverse intensity distributions) allows advanced control..