EurekAlert August 12, 2024 Although progress has been reported in the generation of mutually entangled multi-photon quantum light states using free space apparatus, high-fidelity high-rate on-chip entanglement generation is important for future scalability. An international team of researchers (France, Italy, Brazil) used a bright quantum-dot based single-photon source to demonstrate the high-fidelity generation of 4-photon Greenberg-Horne-Zeilinger (GHZ) states with a low-loss reconfigurable glass photonic circuit. They reconstructed the density matrix of the generated states using full quantum-state tomography reaching an experimental fidelity and purity. The entanglement of the generated states was certified with a semi device-independent approach through the violation […]
Category Archives: Encryption
Engineers develop advanced optical computing method for multiplexed data processing and encryption
Phys.org July 8, 2024 Large-scale and high-dimensional permutation operations are important for various applications in telecommunications and encryption. Researchers at UCLA, California, used all-optical diffractive computing to execute a set of high-dimensional permutation operations between an input and output field-of-view through layer rotations in a diffractive optical network. In this design every diffractive layer had four orientations: 0 deg, 90 deg, 180 deg and 270 deg. Each unique combination of these layers represented a distinct rotation state, tailored for a specific permutation operation. A K-layer rotatable diffractive design could perform up to independent permutation operations. The original input information could […]
New anti-counterfeit technique packs two light-reactive images into one material
Phys.org May 30, 2024 Creating dual-mode patterns in the same area of the material increases the dimension of information storage and encryption security. However different patterns may lead to serious mutual interference in the process of manufacturing and usage. An international team of researchers (USA – Argonne National Laboratory, China) has demonstrated noninterfering dual-mode patterns by combining the structural color and chromatic polarization, which was designed with an azobenzene-containing linear liquid crystal copolymer featuring a photofluidization effect. The secondary imprinting was used to eliminate the partial damage to the structural color patterns during writing of the polarization patterns, thus obtaining […]
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 […]
Novel fluorescent organohydrogel proposed to achieve dual information encryption
Phys.org June 10, 2022 Researchers in China designed an organohydrogel by constructing interpenetrating organohydrogel networks, in which naphthylamide moieties (DEAN, green-yellow emission) are introduced in hydrophilic poly(N,N-dimethylacrylamide) (PDMA) hydrogel network and anthracene units (blue emission) are copolymerized in hydrophobic polystearate methacrylate (PSMA) organogel network. UV light of 365 nm triggers the unimer–dimer transition and leads the fluorescent color of organohydrogel to change from blue to faint yellow. Photomasks store the secret information. They achieved dual encryption by combining crystallization-induced shape memory performance. According to the researchers fluorescent organohydrogel provides a new idea for fabricating smart materials with the ability of […]
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 […]
Using quantum Parrondo’s random walks for encryption
Phys.org October 15, 2021 Quantum game theory has stimulated some interest in recent years with the advancement of quantum information theory. This interest has led to a resurgence of quantum Parrondo’s games. With two losing games combining to give a winning game, this paradoxical idea is known as Parrondo’s paradox. Researchers in Singapore used chaotic switching between the two losing quantum games, to show that it is possible to achieve Parrondo’s paradox involving a quantum walker playing two-sided quantum coin tossing games. They showed that the framework of chaotic switching in quantum coin tosses can be applied to encryption. This […]