Creating Composite Vortex Beams with a Single Geometric Metasurface. Issue 18 (28th March 2022)

• Record Type: Journal Article
• Authors: Ming, Yang; Intaravanne, Yuttana; Ahmed, Hammad; Kenney, Mitchell; Lu, Yan‐qing; Chen, Xianzhong
• Is Part Of: Advanced materials. Volume 34:Issue 18(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-28
• Subjects: composite vortex beams -- optical metasurfaces -- orbital angular momentum -- structured beams; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202109714
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Composite vortex beams (CVBs) have attracted considerable interest recently due to the unique optical properties and potential applications. However, these beams are mainly generated using spatial light modulators, which suffer from large volume, high cost, and limited resolution. Benefiting from the ultrathin nature and unprecedented capability in light manipulation, optical metasurfaces provide a compact platform to perform this task. A metasurface approach to creating these CVBs is proposed and experimentally demonstrated. The design is based on the superposition of multiple circularly polarized vortex beams with different topological charges, which is realized based on a geometric metasurface consisting of metallic nanorods with spatially variant orientations. The effects of the initial phases, amplitude coefficients, incident polarization state, and propagation distance on the generated CVBs, which are in good agreement with the theoretical prediction, are experimentally analyzed. This work has opened a new avenue for engineering CVBs with a minimal footprint, which has promising applications ranging from multiple optical traps to quantum science. Abstract : A compact metasurface approach is proposed and experimentally demonstrated to create composite vortex beams. A single geometric metasurface is used to realize the superposition of multiple vortex beams with different circular polarization states. This method provides a compact platform to generate composite vortex beams with engineered singularity distributions, which are fundamentally important for singular optics and quantum science.