Multidimensional Multiplexing Nested Optical Encryption of Programmable Holographic Structured Light Based on Photoalignment Liquid Crystal Elements

Abstract Recent progress in multidimensional multiplexing offers promising paths for next‐generation optical encryption. However, challenges remain in integration, dimensional expansion, and dynamic tunability. Here, a highly integrated optical encryption strategy is proposed that achieves 8‐channel multiplexing by combining polarization, wavelength, and spatial position within a single liquid crystal (LC) element, greatly increasing information capacity in a compact format. A multi‐layered nested encryption scheme is constructed, where plaintext is first encoded into a password‐protected quick response (QR) code. Decryption involves extracting far‐field holographic keys via wavelength and position, followed by Rivest–Shamir–Adleman (RSA) decryption and 26‐base preprocessing, and finally combining with polarization‐decoded data to retrieve the QR password and recover the plaintext. This hybrid scheme merges physical multiplexing with algorithmic decryption, enhancing both complexity and security. Additionally, the electro‐optical tunability of LCs adds an extra layer of security by allowing on‐demand encryption modulation. The proposed element demonstrates multifunctionality, high integration, and structural simplicity, showing strong potential for secure and scalable applications in optical encryption.