Internet of things security evaluation mechanism based on meta attribute fluctuation.

In the field of Internet of Things (IoT), terminal security has always been an extremely important independent research topic. In the terminal security research, in addition to the security enhancement of terminal entities, the security status evaluation of terminal security has also become an independent subset of the security research in the IoT field. However, it should also be noted that the security attributes of IoT terminals can include many aspects, so judging the security of IoT terminals based on the overall security form is not enough for the security of terminal entities.

Terahertz hybrid optical-plasmonic modes: tunable resonant frequency, narrow linewidth, and strong local field enhancement.

Hybrid optical-plasmonic modes have the characteristics of low loss and small mode volume, which will result in the strong localization and enhancement of electromagnetic field. Such advantages of hybrid optical-plasmonic mode are important for the enhancement of light-matter interactions. Here, terahertz (THz) hybrid modes of Fabry-Perot resonances (FPRs) and spoof surface plasmon polaritons (SSPPs) in the modified Otto scheme are investigated both in theoretical and experimental aspects.

Geometry phase for generating multiple focal points with different polarization states.

Conventional lenses are always large and bulky to achieve desired wave-manipulating functions, hindering the development of integrated and miniaturized optical systems. Metasurfaces, two-dimensional counterparts of metamaterials, can accurately tailor the wavefront of electromagnetic waves at subwavelength scale, providing a flexible platform for designing ultra-compact and ultra-flat lenses, namely as metalenses. However, the previous geometry-phase-based metalenses usually generate focal point(s) with only one special polarization state, i.