In this work, we show the conversion of a Gaussian beam into an annular vortex beam (AVB) by means of an optical vortex element (OVE). This is a simple phase plate which generates the AVB at a determined distance without the use of external optical elements such as lenses and axicons. We discuss the interesting features and the advantages of the OVE respect to other methods to generate AVB such as the conventional vortex (CV) and the helical axicon (HA). The OVE presents the highest intensity peak respect to both the CV and the HA. Another important feature is that the OVE and the HA maintain a fixed annular radius; in contrast the CV changes the annular radius, while the topological charge is modified. The OVE is displayed on a spatial light modulator (SLM) in order to generate experimentally the AVBs. We demonstrate the features of the AVB generated and measure the high angular velocities achieved due to the angular momentum transfer to 3 μm particles.
In this work, we present numerical and experimental generation of reconfigurable vector beams employing synthetic phase holograms (SPH) that provide the optimum diffraction efficiency and high quality of reconstruction. The vector beams with spatially variable polarization are generated by the linear recombination of two orthogonally homogeneous polarized scalar modes. The scalar modes are generated with a SPH displayed in a phase-only Spatial Light Modulator (SLM) and superimposed using a common-path interferometer which consists of a 4-f system. We demonstrate the generation of high order TE and TM vector Bessel, Mathieu and Weber beams which could be used for optical trapping applications.