Leveraging statistical – spectral correlations of random metasurfaces for steganography and multi-wavelength cryptography

• Romil Audhkhasi, Maksym Zhelyeznyakov, Steven Brunton, and Arka Majumdar
• received 03/14/2024; accepted 04/16/2024; posted 04/17/2024; Doc. ID 523914
• Abstract: The ability to tailor the spectral response of photonic devices is paramount to theadvancement of a broad range of applications. The vast design space offered by disorderedoptical media provides enhanced functionality for spectral tailoring, while also making itchallenging to map the spectral properties of such complex systems to their structural attributes.In this work, we investigate correlations between the configuration statistics of randommetasurfaces and their spectral transmissivity in the visible, and leverage those to develop areduced phase space. In the latter part of the manuscript, we use this reduced phase space todesign a pixelated color filter that hides visual data within a preselected cover image forsteganography. Furthermore, we design a pair of color filters that can collectively encrypt agiven grayscale image in their spectral transmissivities. We envision such devices to createopportunities for the development of compact, next-generation cryptographic systems. Morebroadly, the results presented in this manuscript provide new avenues for optimizing large-scalerandom metasurfaces to achieve enhanced optical functionalities for a wide variety ofapplications.