Arbitrary designer mode convertor and on-chip OAM generator with configurable topological charge using waveguide-integrated metasurface

Leveraging waveguide-integrated metasurface platform, designer mode convertors capable of exclusively exciting arbitrary high-order modes with high-purity reaching 98% are proposed. We also report on-chip scalable broadband vortex-beam-generators with configurable topological charge from -3 to +3.