Efficient generation of arrays of closed-packed high-quality light rings

Abstract

Recently, structured laser beams are gaining attention in laser–matter interactions and related applications of metamaterials and metasurfaces. Ablative laser printing using ultrashort, femto- or picosecond, structured laser pulses allows the large-scale, high-throughput, single-step fabrication of surface nano- or microelement arrays. In this paper, for the purpose of laser printing of arrays of micro and nanoring structures, we investigate the generation of closed-packed light rings with a minimum possible diameter using a combination of a light ring distribution generator and a diffractive beam splitter. As a light ring distribution generator, we use the well-known S-waveplate and generate three different types of ring-shaped laser beams: an azimuthally polarized Gaussian beam, a first-order circularly polarized optical vortex beam, and a first-order linearly polarized optical vortex beam. Our modeling and experimental results show that the azimuthally polarized Gaussian beam is the best solution for splitting in comparison with the other types of beams.