Fig. 6: Active optical waveguide and information encryption design.
From: A solid-solution approach for controllable photomechanical crystalline materials
a Illustration of the active optical waveguides under 405 nm excitation. Active optical waveguide of (b) 9AA, (c) (9AA)0.9(9MA)0.1, (d) heterostructure crystal and the spectra collected from the tip with increasing transmission distance. e Schematic of the preparation and use of encryption paper and ink. f Images of encryption paper before and after writing under ambient light and 405 nm light.
