Fig. 3: Exponentally expanded key space and design of high-precision holograms.
From: Ultrahigh-speed optical encryption enabled by spatiotemporal noise chaffing
a Parameters defining the key space of CVW-multimodal OAM: the largest order of OAM modes supported by system (L), the number of modes selected for CVW-multimodal OAM (M), and the weight precision (δ). b Key space size for different weight precisions (δ = 0.5,δ = 0.25,δ = 0.125, and δ = 0.1, respectively). c Mean crosstalk value and SNR from 1000 random samplings, showing the effect of increasing δ for different M with a fixed L = 20. d Schematic of a multimodal OAM generation neural network for single hologram broadcasting of CVW-multimodal OAM. e Concept of single hologram generation for CVW-multimodal OAM and comparison of simulation and experimental results for direct mode overlap and MGNN. f Error comparison between different methods (direct overlapping, pattern search optimization, and MGNN) for CVW-multimodal OAM hologram generation.
