Vortices Lattices

Abstract

Multiple vortex beams with various topological charges are usually essential for vortex beams system. An easy way to obtain multiple vortex beams, is to generate multiple single vortex beams, and then introducing them into one system. However, this scheme is complex and inconvenient. Such issue can be well addressed if we can generate multiple vortex beams simultaneously in one system. The basic idea is to design a special diffraction grating, which can diffract the incident Gaussian beams into various diffraction orders and meanwhile introduce various topological charges separately. Then in the far-field plane one can obtain multiple vortex beams in different positions, known as vortices lattices. Vortex beams lattices can be divided into three main classes, the dipole vortices lattice, the unipolar vortices lattice and the neither diploe nor unipolar vortices lattice. For unipolar vortices lattice, the topological charges of all the vortices in the lattice are identical; For dipole vortices lattice, the topological charges of vortex beams at each diffraction order is generally different, but that at the opposite diffraction order is opposite, and the sum of the topological charges of all the vortices in the lattice is 0. The neither diploe nor unipolar vortices lattice is the lattice that neither satisfies the unipolar condition nor the dipolar condition. In this chapter, various vortices lattices and there generating approaches are introduced from the point of designing diffraction gratings.