Generation of Tunable Plasmonic Vortices by Varying Wavelength of Incident Light

Surfaces plasmon polaritons carrying orbital angular momentum (OAM), known as plasmonic vortex, hold potential applications for on-chip information multiplexing. However, a traditional vortex lens was usually designed monochromatic incident light and encountered challenges in generating multiple vortices. Here, we demonstrated wavelength-tunable generator that ameliorates these limits, relying on the simultaneous design of geometric metasurface an Archimedean spiral. Through this strategy, both topological charges location vortices can be controlled with different wavelengths beams. This concept preserve wavelength further applied to integrated high-dimensional devices.