Pseudo non-diffracting beam array through high-indexed dielectric metaplate

Highly non-diffracting Bessel beams have gathered an excessive amount of significance due to their several applications ranging from optical communication, and displays to trapping and manipulation. The array of Bessel beams with multiple orders is generated by utilizing geometric metasurfaces to have full phase control over the optical properties of light. In prior works, Bessel beams are realized with optical metasurfaces of titanium dioxide (TiO2) and gallium nitride (GaN) but they have bottlenecks in terms of complex and expensive fabrication. Here, in this manuscript, we have represented a single-layer optical metasurface based on gallium phosphide (GaP) for Bessel beam generation. The proposed metasurface has high transmission efficiency in the visible regime and is capable of producing four Bessel beams of arbitrary orders without the accumulation of extra complexities in conventional nano-rectangular pillar geometry. Due to the property of orbital angular momentum, these arbitrary order Bessel beams have a high capacity for data storage. Thus, they provide an appropriate platform for numerous interesting phenomena of data encryption and information storage.