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Heading towards to intelligent photonic technology, meta‐optics is in the revolutionary process of changing from passive to active controllable devices. Despite various emerging tuning mechanisms exploration and demonstration, they mainly focus on spectral amplitude alternation or near‐field imaging switch. Most tuning schemes inevitably demand quite complicated nanofabrication to incorporate nanotextured active materials, thus limiting its applicable scenarios outside the laboratory. Hence, a practically accessible solution in real life to simultaneously realize multi‐field (both near‐ and far‐field) dynamic displays remains a critical challenge. Here, a practical electric‐driven liquid‐crystal‐integrated metasurface (ELIM) is proposed and demonstrated toward advanced intelligent dynamic display. Through elaborately screening building block (α‐Si nanopillar) geometry to build up a systematic architectural dictionary, conventional spatial‐multiplexing is successfully achieved and the degeneracy for amplitude/phase selections is created and thus any arbitrary multi‐field encryptions are allowed. By leveraging ELIM anisotropic characteristics for orthogonal polarizations, an electric‐driven dynamic tuning is practically realized for the first time to enable quad‐fold dynamic exhibitions, including switchable dual‐nanoprinting (near‐field) and simultaneous dual‐holography (far‐field) images with independent‐encryption freedom. Overall, it is envisioned that meta‐optics integrated with the liquid‐crystal platform can easily find practical applications in real life for intelligent dynamic display, imaging multiplexing, information encryption/security, etc. [ABSTRACT FROM AUTHOR]

In order to promote the application of piezoelectric fiber and its composites in the field of intelligent fabrics, the recent research progress of piezoelectric fiber and its composites at home and abroad was summarized. The preparation methods of piezoelectric ceramic fiber, PVDF piezoelectric fiber and other piezoelectric fibers and their composites were systematically introduced. The performance characteristics of these piezoelectric materials and the advantages and disadvantages of these methods were analyzed. At the same time, the applications of piezoelectric sensors in the fields of wearable intelligent fabrics, bionic deformation and medical health were introduced. Finally, the existing problems of piezoelectric fiber and its composites in the field of intelligent fabrics were summarized, and the future development trend was prospected. [ABSTRACT FROM AUTHOR]

Metallic patterned metasurfaces can effectively manipulate the propagation of surface plasmonic waves in the near-field regime. Extraordinary optical phenomena such as diffraction-free propagation also have been enabled by periodic uniform metallic grating metasurfaces (UMGM). However, such metallic patterned metasurfaces usually exhibit a relatively narrow-band non-diffractive property and the realization of visible-frequency broadband diffraction-free on-chip propagation has been quite challenging due to intensive structural dispersive and sensitive wavelength selectivity. Here, we proposed a novel design of a hybrid metallic grating metasurface (HMGM) with two different ridge widths, which could display a broadband diffraction-free on-chip propagation in the visible frequency. By optimization and appropriate hybridization of the ridges of different widths, it enables effective modication of the dispersion of surface plasmons, thus forming the broadband diffraction-free characteristics. Compared to the UMGM, our proposed HMGM can facilitate enhanced propagation of the surface plasmon polaritons and strongly confine the surface plasmonic field to the deep-subwavelength scale. With such hybrid implementation, the surface plasmonic waves propagate parallel to the ridges and their wavefronts remain the original shape without diverging at the broadband wavelength of 600 nm–800 nm. Overall, such broadband diffraction-free propagation along the HMGM could find many potential applications in on-chip plasmonic devices including sub-diffraction resolution imaging, hyperlenses, and photon routing, etc. [ABSTRACT FROM AUTHOR]

As an emerging field in the discipline of optics, plasmonics and metasurfaces have been demonstrated to enable a new degree of freedom to manipulate light for arbitrary beam steering, spectral splitting as well as precise wavefront shaping. However, it has been mostly studied in parallel with the field of diffractive optics, and awaits the unveiling of how the hybridizations between plasmonic effect and diffraction effect interact and impact. Here, we have theoretically proposed a new type of polarization-insensitive meta-grating structure across the broadband visible regime. The structure design combines the width gradient (critical resonant length) from a trapezoid-nanoantenna with the height gradient from a blazed grating profile. The hybridized meta-grating creates both plasmonic effect and grating effect, which enables all the optical incident photons to be directed to the same orientation regardless of the light polarization. As we know, both metasurfaces and diffractive optical elements (such as gratings) are, more often than not, quite sensitive to the incident light polarization. Moreover, if placing our meta-grating on a flexible/stretchable substrate (such as polydimethylsiloxane), the outgoing angle can be effectively adjusted by tuning the period or density of meta-grating arrays. Such meta-grating architectures can be potentially manufactured by existing photolithography and nanoimprint techniques, and can easily find a wide range of practical polarization-insensitive applications, including broadband deflector and emitter, tunable display and imaging device, high signal-to-noise ratio spectrometer, polarization-insensitive plasmonic coupler, etc. [ABSTRACT FROM AUTHOR]

On the Qinghai-Tibet Plateau, permafrost degradation and associated release of permafrost meltwater has undoubtedly modified the annual and seasonal streamflow patterns and influenced groundwater conditions. However, it is still unclear how extensively permafrost degradation has influenced surface and subsurface water systems due to very sparse observations. Isotope mass models combining tritium and 222Rn measurements are developed here to quantify the contributions of groundwater discharge and thawing permafrost to rivers and lakes in the Source Area of the Yellow River. Results demonstrate the spatial variability of permafrost thaw impacts and confirm significant influence on surface and subsurface runoff processes including effects on water yield capacity and water drainage connectivity. While results to date are conclusive, further work to refine the method and extend observations is warranted. [ABSTRACT FROM AUTHOR]