High-security optical encryption based on single-pixel imaging and structured light multiplexing holography

The applications of single-pixel imaging (SPI) and optical multiplexing techniques in optical encryption are gradually increasing. However, little attention has been given to integrating these two for applications. Here, we propose a dual-layer optical encryption scheme that combines sample region-dependent SPI and structured light multiplexing holography. In the encryption process, the bucket signal obtained by SPI and the position coordinates used to generate the structured illumination patterns for SPI will be encrypted into a holographic ciphertext through spatial-structured light multiplexing holography. During decryption, the bucket signal can be retrieved from the ciphertext using a binary matrix key, and the sampling region can be determined by illuminating the ciphertext with multi-ramp helical-conical beams. Thus, the original secret image can be successfully decrypted. This work takes advantage of the spatial mode multiplexing characteristics of the structured beams and the dependence of Fourier SPI encryption on the sampling region, thereby promoting the collaborative application of the two in the field of optical security.