Metasurface-based perfect vortex beam for optical eraser

Perfect vortex beams (PVBs) take advantage of conventional vortex beams regarding their property of constant diameter of the annular intensity distribution on different topological charges (TCs), facilitating spatially coupling multiple beams with different TCs simultaneously. However, there are demands for PVBs with larger TCs that can be integrated with CMOS-fabrication processes in applications since conditional PVBs are composed of bulky optical components. In this work, we demonstrate metasurface-based PVBs (MPVBs) with TCs as high as -32 and 16 in the visible, manifesting annular intensity distributions capable of broadband operation. The optical eraser concept by integrating MPVBs has been conducted, and the flower-like interference performs a helicity switch to facilitate the uniformization of ring-shaped intensity profiles for the MPVBs with different TCs. The optical eraser experiments demonstrate the potential of MPVBs in advancing both quantum optics and optical device engineering and pave the way for probing quantum behaviors in optics.

Vin-Cent Su, Chia-Hung Chiang, Meng-Hsin Chen, Kai-Lun Xu, Shao-Yang Huang