Ultra-High Secure Holographically Steganographic Array with Spatiotemporal Dual-Encryption Keys

Independently-manipulated optical encryption has attracted great attention due to its high security and multiple application scenarios. Although photochromic molecules have become preferred holographic display units, the integration of dynamic modulation both in hologram and fluorescence for orthogonal encryption is still challenged. Herein, a latticed holographically steganographic array is constructed by incorporating a plasticizer (tri-o-cresyl phosphate, TOCP) into spirooxazine (SO) based polymers, thereby modulating the isomerization rate and the UV-fluorescence kinetics between SO and merocyanine (MC). The period to reach fluorescence saturated value for each information bit in the latticed device can be widely modulated between 60 and 1700 s. Based on the property, only through ultraviolet stimulation can array information gradually be converted from spatial lattice coordinates to holographic display time. Then, a hidden 3D image can be determined from rapidly updatable reconstructed hologram video with refresh rate 1.125 Hz by the above spatiotemporal dual-encryption keys. This work provides a bright path for the ultra-high safety steganography and adaptive stereoscopic imaging.