Security-Enhanced and High-Resolution Fractional Orbital Angular Momentum Multiplexing Holography

In this paper, we propose a security-enhanced and high-resolution fractional orbital angular momentum (FOAM) multiplexing holography, which is a novel approach that can overcome the inherent limitations of traditional OAM-multiplexing holography, named FOAM holography. In the encoding, each sampling point with FOAM characteristics is added to the target hologram and the denser topological charge (TC) values of FOAM are employed to generate the FOAM-multiplexing hologram. An inverse FOAM mode is adopted to illuminate the FOAM-multiplexing hologram for decoding, and the threshold of intensity is set up to extract the encoding information. Experiment results validate the feasibility of the proposed FOAM holography and demonstrate that the proposed FOAM-multiplexing hologram can be successfully decoded when the FOAM modes interval is as small as 0.3. Experimental results also indicate that the proposed FOAM holography has enhanced security in optical encryption and a higher resolution for displaying. It provides a promising prospect for optical encryption and holographic imaging.