Meta-fibers: merging metasurfaces with optical fibers via 3D nanoprinting for flexible beam manipulation (Invited Paper)

The integration of metasurfaces onto the end faces of optical fibers holds great promise for numerous applications. Traditional top-down fabrication struggles with optical fiber geometry. Our presentation reveals a solution: 3D nanoprinting via direct laser writing to create nanopillar metasurfaces on fiber end faces. This concept gives rise to a novel kind of fiber devices called meta-fibers, allowing for shaping the fiber's output properties. We showcase two applications: (i) achromatic fiber-interfaced metasurface lenses covering the entire telecommunication range, and (ii) meta-fibers generating structured light. These meta-fibers utilize dielectric nanopillars of varying heights, a capability unique to the nanoprinting process.