Iterative phase retrieval for simultaneously generating two phase-only masks with silhouette removal in interference-based optical encryption

We propose a novel method using iterative phase retrieval for simultaneously generating two phase-only masks with silhouette removal in interference-based optical encryption system. Different from previous works, an iterative phase retrieval algorithm is developed for simultaneously generating two phase-only masks in the different optical paths, and no additional keys (or masks) or complementary algorithms are required. Silhouette problem inherent in conventional interference-based encryption method is fully resolved, and the higher security can be correspondingly achieved.