Numerical Derivation of Dual Vortex Beam Generation using Polarization-Sensitive Dielectric Metasurfaces

Metasurfaces, composed of arranged nanoscale particles, manipulate electromagnetic waves for tailored physical properties. Recently vortex beams, carrying orbital angular momentum, have been generated through metasurfaces to realize diverse applications. Here, the study introduces a metasurface capable of generating dual-mode vortex beams, which combines the functionalities of chiral metalenses and vortex beam generation. These dual-mode vortex beams exhibit varying characteristics depending on the polarization state of the incident light, offering improved control over orbital angular momentum. This advancement holds promise for enhancing applications such as optical communication, optical tweezers, and imaging for overcoming diffraction limit. By employing titanium dioxide (TiO2) for its efficiency, the design concept is validated through simulations and discuss considerations for fabrication. The proposed approach paves the way for compact optical systems with heightened adaptability. The study presents a metasurface that creates dual-mode vortex beams by combining chiral metalenses and vortex beam functionalities. These beams, controlled by incident light polarization, enhance orbital angular momentum control. Validated through simulations with low-loss titanium dioxide (TiO2), the design enables compact and adaptable optical systems. image