High-efficiency generation of Bessel beams with transmissive metasurfaces

Abstract

Circularly polarized Bessel beams (BBs) are important in biomolecule-sensing-related applications, but the available generators are too bulky in size and/or exhibit low efficiencies. Here, we design and fabricate ultra-thin (∼λ/6) transmissive Pancharatnam-Berry metasurfaces and perform near-field scanning measurements to show that they can generate circularly polarized BBs within a frequency window of 10.7–12.3 GHz. We experimentally demonstrate that the generated BBs exhibit a self-healing effect, illustrating their non-diffraction characteristics. Finally, we employ far-field measurements to demonstrate that the working efficiency of our devices can reach 91%, while the simulated efficiency reaches 92%. All experimental results are in perfect agreement with full-wave simulations.