Fig. 3: Experimental characterization of an AM meta-hologram with 16-bit independent holographic images.
From: Angular momentum holography via a minimalist metasurface for optical nested encryption
a, b Top and side views SEM images of the fabricated meta-hologram, with the scale bar to be 1 μm. c Characterizing system for the measurement of fabricated meta-hologram, where a spatial light modulator (SLM) along with a quarter waveplate (QWP) are used to generate required CP vortex beams. BS: beam splitter, SLM: spatial light modulator, M: mirror, CCD: charge-coupled device. The dashed boxes indicate that the QWP is removable in the certain measuring process. d Numerical and experimental reconstruction of the eight distinctive SOL holographic images through incident CP vortex beams with specific |σ, l > . e Numerical and experimental reconstruction of the eight distinctive SS holographic images through a XLP incident light and extracting certain SoPs via utilizing specific analyzers. The corresponding SoPs of the eight holographic images indicate by eight points on the PS
