Generation of non-diffractive Lommel beams based on all-dielectric metasurfaces

Abstract

Lommel beam is a non-diffractive vortex beam of high concern recently, widely used in communication and turbulence studies. However, conventional methods of generating Lommel beams, such as using spatial light modulators (SLMs), are limited by their low resolution, poor phase manipulation, and small numerical aperture (NA). Here, non-diffractive Lommel beams based on all-dielectric metasurfaces are proposed. Using the Pancharatnam-Berry (PB) phase arrangement, the focal depth of the main lobe of the generated beam can reach 75 µm (∼119λ). Additionally, the broadband characteristics of the designed metasurface between 550 and 710 nm are observed. The resulting beam is demonstrated to show excellent self-healing properties by placing up obstacles. We also combine the phase of the Dammann grating with that of the Lommel beam to create a metasurface capable of producing a 1 × 4 Lommel beam array; the generated beams are still characterized by uniformity and non-diffraction. This study provides a new idea for Lommel beam generation with promising applications in optical communication, optical tweezers, and laser fabrication.

Performance analysis of an underwater wireless optical communication link with Lommel beam

“…As a kind of diffraction-free vortex beam, the Lommel mode [31] can be generated by digital binary amplitude masks [32], highly scattering media [33] or all-dielectric metasurfaces [34]. Specifically, the Lommel mode has symmetric transverse intensity, continuously varying OAM and orthogonal transverse wave numbers, with each of these characteristics contributing to its diverse beam structures.…”

Bessel beams generation with biphase transition of vanadium dioxide metasurface

“…The increasing complexity in designing additional functionalities has resulted in a decreased flexibility in wavefront modulation. These challenges have motivated ongoing research aimed at creating metasurfaces that offer highly efficient transmission, tunable functionality, and simplicity in design, spotlighting the pursuit of optimizing optical devices for broader applications [12][13][14][15].…”