Reprogrammable metasurface holographic image encryption technology based on a three-dimensional discrete hyperchaotic system.

The emergence of metasurfaces provides a secure and efficient platform for optical encryption technology as they have broad prospects in the field of information security. However, the limited number of channels available on metasurfaces and the insufficient security of keys make them vulnerable to attacks by eavesdroppers. In this work, a reprogrammable metasurface optical encryption scheme based on a three-dimensional hyperchaotic system is proposed.

Double-exponential refractive index sensitivity of metal-semiconductor core-shell nanoparticles: the effects of dual-plasmon resonances and red-shift.

In order to improve the refractive index sensitivity of a localized surface plasmon resonance (LSPR) sensor, we present a new type of LSPR sensor whose refractive index sensitivity can be improved by greatly increasing the plasmon wavelength red-shift of metal-semiconductor core-shell nanoparticles (CSNs). Using extended Mie theory and Au@Cu S CSNs, we theoretically investigate the optical properties of metal-semiconductor CSNs in the entire near-infrared band. Compared with dielectric-metal and metal-metal CSNs under the same conditions, the metal-semiconductor CSNs have a higher double-exponential sensitivity curve because their core and shell respectively support two LSPRs that greatly increase the LSPR red-shift to the entire near-infrared range.