Distinct geometry-induced optical chirality in vertically nanoprinted hollow-core light cages

Controlling light in photonic waveguides with embedded chirality is essential for advancing emerging technologies in quantum optics, biosensing, and optical communications, yet planar-photonic integration of such chiral structures has long been limited by fabrication and design constraints. In this work, we introduce vertically nanoprinted twisted light cages (tLCs) as a new class, to our knowledge, of chiral hollow-core waveguides that combine record-high geometric twists with strong optical chirality. These waveguides support the robust formation of circularly polarized eigenmodes and exhibit record-high circular birefringence and circular dichroism, even at sub-millimeter lengths. Beyond enabling strong chiral light–matter interaction, tLCs offer a compact and versatile platform for complex light manipulation—alternative to metasurfaces and resonant structures. Their lateral core access and compatibility with planar integration pave the way for advanced polarization control and structured light applications, bridging the gap between chiral photonics and next-generation integrated photonic systems.