Backyard insect inspires invisibility devices, next gen tech

Phys.org  March 18, 2024 The leafhoppers cover their body surfaces with brochosomes, buckyball-shaped, nanoscopic spheroids with through-holes distributed across their surfaces, representing a class of deployable optical materials that are rare in nature. A team of researchers in the US (University of Pennsylvania, Carnegie Mellon University) investigated the optical form-to-function relationship of brochosomes and demonstrated that the hierarchical geometries of brochosomes are engineered within a narrow size range with through-hole architecture to significantly reduce light reflection. They showed that the diameters of brochosomes are engineered to maximize broadband light scattering, while the secondary through-holes are designed to function as short-wavelength, […]

Optical encryption method based on single pixel imaging and metasurface holography

Nanowerk  September 26, 2022 The precise control of phase, amplitude, polarization, metasurface holography provides a flexible platform for light modulation, optical encryption. The process of image reconstruction by single pixel imaging is similar to a form of encoding and decoding, which is realized by calculating the correlation between a series of modulation patterns and their corresponding intensity signals. Researchers in China proposed an optical encryption scheme based on spatial multiplexing metasurface, which depends on the combination of holographic technology and single pixel imaging technology. In the encryption scheme, the image transmitted by single pixel imaging based on metasurface was used […]

Photonic encryption platform in the ultraviolet and visible

Science  Daily March 17, 2022 Researchers in South Korea have developed an optical encryption platform that works simultaneously in the visible and ultraviolet (UV) regimes. They adjusted the physical properties of silicon nitride to reduce its tendency to absorb ultraviolet light. They fabricated a metahologram in which an image clearly appears when ultraviolet laser is irradiated on it. They combined the two metaholograms that work in the ultraviolet and visible light regions to create an anticounterfeiting device that displays a unique product number. The hologram that appears when a visible light laser is irradiated acts as a key and when […]