Secure data transmission requires robust encryption strategies to prevent unauthorized access. Although software-based encryption has been extensively explored, advances in high-speed computing and the development of quantum systems increasingly challenge the security of conventional schemes. Hardware-based encryption offers an alternative approach by exploiting physical properties of light and engineered structures. In this work, we present a metasurface-based hardware encryption system that simultaneously leverages polarization encoding and orbital angular momentum (OAM) wavefront encoding. The system operates across three distinct channels. The first channel, with input and output polarization [Formula: see text], generates OAM superpositions [Formula: see text] at the focal point.
Orbital angular momentum-based spatial encryption using polarization-sensitive metasurfaces
