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    anti-counterfeiting tagged posts

    Unhackable metasurface holograms: Security technology can lock information with light color and distance

    February 5, 2026, Categories  Physics, Technology/Electronics

    Schematic of secure holography using a reconfigurable stacked metasurface based on a modular diffractive deep neural network. Each metasurface layer independently reconstructs distinct wavelength-encoded holograms (e.g., ID and QR). When two layers are aligned at a specific interlayer spacing, the system is trained to reveal an encrypted hologram (PW). Because decryption is enabled by the combined choice of wavelength and interlayer spacing as physical decoding keys, the information can be retrieved without electronic computation. This single platform integrates standalone (layer-wise), combinational (cipher), and multi-wavelength functionalities, enabling a photonic security platform for optical encryption and data storage. Credit: POSTECH

    A research team led by Professor Junsuk Rho a...

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    Researchers report Quantum-limit-approaching Chemical Sensing Chip

    January 13, 2021, Categories  Chemistry/Nanotechnology

    An illustration of the chip. A gloved hand holds a thin gold film which is struck by a beam of red light. An inset shows the chemical element abbreviations for gold and silver and the particles illuminated by the light.
    The chip, which also may have uses in food safety monitoring, anti-counterfeiting and other fields where trace chemicals are analyzed. Credit: Huaxiu Chen, University at Buffalo.

    Study shows improvements to chemical sensing chip that aims to quickly and accurately identify drugs and other trace chemicals. University at Buffalo researchers are reporting an advancement of a chemical sensing chip that could lead to handheld devices that detect trace chemicals — everything from illicit drugs to pollution — as quickly as a breathalyzer identifies alcohol.

    The chip, which also may have uses in food safety monitoring, anti-counterfeiting and other fields where trace chemicals are analyzed, is described in a study that appears on the cover of the Dec...

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