Fig. 5. Spin-multiplexed near-UV self-accelerating beam generator.

a, b Schematic representation of the generation of a self-accelerating beam by the spin-multiplexed metasurface, ${\mathrm{B}}_{364}^{\mathrm{spin}}$, under normal-incidence, plane-wave LCP a or RCP b illumination at λ₀ = 364 nm. c Measured transverse deflection in different z planes (ranging from 2.5 to 4.5 mm, with an increment of 0.5 mm) for LCP illumination of ${\mathrm{B}}_{364}^{\mathrm{spin}}$ at its operation wavelength of λ₀ = 364 nm. The error bars denote one standard deviation of the measured data. The targeted beam trajectory, $d=16z^2$, is shown for reference. d Measured transverse deflection in different z planes (ranging from 4.5 to 10.5 mm, with an increment of 1.5 mm) for RCP illumination of ${\mathrm{B}}_{364}^{\mathrm{spin}}$ at its operation wavelength of λ₀ = 364 nm. The error bars denote one standard deviation of the measured data. The targeted beam trajectory, $d=2.25z^2$, is shown for reference. e, f Measured xy-plane intensity distributions (normalized) in different z planes for the device at its designated wavelength of operation under either LCP illumination e or RCP illumination f. Each distribution is displayed over an equal square area with a side length of 140 µm but shifted along the −xy e or xy f direction as a function of increasing z, such that the center of the main lobe maintains an invariant position within each image