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Structured light beams have attracted significant interest due to their versatile spatial or spatiotemporal configurations, which can potentially transform various real-world applications not achievable using conventional Gaussian beams. Bessel beams, with their non-diffracting properties, have proved themselves to be a phenomenal alternative in numerous scenarios where Gaussian beams were traditionally expected to excel. Therefore, numerous devices have been proposed to generate such non-diffracting beams via ultrathin and compact platforms of artificially engineered subwavelength thick structures, acknowledging the significance of chip-scale integration. However, selecting element/elements with their geometry influences and imposes limitations on many applications. Here, we demonstrate a geometric phase-based all-dielectric, highly efficient (≈ 80%) polarization-insensitive compact transmissive structure. Our metastructure utilizes zinc sulfide as an elementary material, designed to operate in the visible spectrum (475− 650 nm) due to its favorable optical constants. The proposed design philosophy is affirmed by a straightforward approach that effectively handles the persistent challenge of polarization-insensitive light structuring across a broader spectrum using a distinct single-cell-driven, single-layered metastructure. For proof of concept, numerical simulations utilizing the Finite Difference Time Domain (FDTD) method validate our idea, demonstrating second-order Bessel beams under various polarization states (e.g., linear and circular) for the visible spectrum. We are confident that generating polarization-independent Bessel beams of zeroth or higher order within a visible domain of the electromagnetic spectrum can unlock promising possibilities for numerous advanced applications, such as imaging, laser fabrication, optical manipulation, and beyond.
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