Quasi-Talbot effect with vortex beams and formation of vortex beamlet arrays

Abstract

We study diffraction of Bessel vortex beams with topological charges of ±1 and ±2 and a wavelength of 130 µm on two-dimensional amplitude periodic gratings. Results of simulations and experiments at the Novosibirsk Free Electron Laser facility show that there appear periodic patterns in the planes corresponding to the classical main and fractional Talbot planes, but instead of self-images of the holes, there are observed periodic lattices of annular vortex microbeams with topological charges corresponding to the charge of the beam illuminating the grating. The ring diameters are the same for beams with different topological charges, but they are proportional to the grating period and inversely proportional to the diameter of the beam illuminating the grating.

Controlled generation of array beams of higher order orbital angular momentum and study of their frequency-doubling characteristics

“…However, in addition to the difficulty of manufacturing such devices, the power loss in such devices restricts their use for high power operations. On the other hand, plasmonic metasurface nano apertures 14 and amplitude gratings 15 have produced optical vortex arrays in Talbot planes through self-imaging. Unfortunately, the stringent dependence of the input grating parameters on the self-imaging, results in limited or no control on the properties of the vortex array.…”

Two-dimensional Talbot effect of the optical vortices and their spatial evolution

“…This phenomenon is well-studied, both theoretically and experimentally, for plane waves 33 and theoretically investigated for the beams comprising phase singularities 20,34,35 . In the experiment, the Talbot effect of the OAM-carrying beams was observed in the 1D case 31 , as well as for the two-dimensional configuration at the THz radiation 35,36 and near-infrared single photons 37 . In the 1D case 31 , the experimental intensity patterns were in the form of a periodic set of stripes, while for two-dimensional configuration there is an array of beams with a topological charge.…”

3D Optical Vortex Lattices

“…[ 17 ] The OV arrays can be created by multibeam interference, [ 18,19 ] diffraction on Damman gratings, [ 20 ] or using the Talbot effect. [ 21 ] Besides, in ref. [22] it was proposed a method for producing a close‐packed 2D OV lattice with a controllable structure in the far‐field.…”

“…[22] it was proposed a method for producing a close‐packed 2D OV lattice with a controllable structure in the far‐field. So far, the investigations of the OV arrays have been limited to the cross sections of the 3D spatial distributions, [ 21,23 ] except for the 3D reconstruction of a unit cell, [ 18,24 ] although 3D optical lattices without TCs have been intensively studied. [ 9,25 ] A spatial array of the OVs regular in the three dimensions (a 3D lattice) is of particular interest, since it offers unique possibilities for light‐matter interactions, which cannot be obtained using optical lattices without TCs.…”