Near-zero-sidelobe optical subwavelength asymmetric focusing lens with dual-layer metasurfaces

The existing metasurfaces with ultrathin volume for asymmetric transmission were often constructed by metal with low efficiency in optical frequency, and could not realize the optical asymmetric transmission and focusing simultaneously. Although the acoustic asymmetric focusing in asymmetric focusing lens (AFL) was realized, the obtained focal point was accompanied by large sidelobe. To solve those problems, an AFL with dual-layer metasurfaces designed by using dielectric materials can realize optical asymmetric transmission and focusing simultaneously in this paper. Furtherly, through optimizing the design theory of AFL, the near-zero-sidelobe (NZS) focusing can be realized on the subwavelength scale. The NZS asymmetric focusing of the optimized AFL is effective in broadband, which is expected to possess tremendous potential in the optical micro-nano processing, quantum communication, optical micromanipulation, etc

In Situ Synergistic Ti₂CT_<i>x</i>/W₁₈O₄₉ Heterostructure for Photoelectrochemical Photodetector with Improved and Durable Photoresponse

Ti2CTx is a typical 2D layered semiconductor material with a high carrier mobility and intriguing photodetector performance. In this work, a Ti2CTx/W18O49 heterostructure was fabricated via a simple one-pot hydrothermal method. The photoelectrochemical (PEC)-type photodetector was constructed by using the as-prepared composite as the electrode material. The Ti2CTx/W18O49 heterostructure clearly exhibited a significant increase in photoresponse compared to that of solitary Ti2CTx and W18O49, as shown by the results of the PEC tests. This demonstrates how the Ti2CTx and W18O49 interface effectively generates and transfers photocarriers, which can enhance the photoresponse performance. Additionally, the constructed Ti2CTx/W18O49 heterostructure-based photodetector’s photocurrent density can practically linearly increase as the irradiation power density rises. The photocurrent density and photoresponsivity can reach 1.42 μA/cm2 and 19.6 μA/W at 0.6 V, respectively. The prepared Ti2CTx/W18O49 heterostructure-based photodetector also shows excellent cycle stability; after more than 2500 s and 125 on/off cycles, the photocurrent shows no obvious attenuation. The superb PEC-type photodetector performance of a Ti2CTx/W18O49 heterostructure holds much promise for photodetection

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Movie for the transmission evolution of HG beams in the FSE with two dimensions under α=1.8 when β=1

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Movie for the transmission evolution of HG beams in the FSE with two dimensions under β=-0.6 when α=

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Movie for the transmission evolution of HG beams in the FSE with two dimensions under β=14 when α=

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Movie for the transmission evolution of HG beams in the FSE with two dimensions when α=1.8, μ=

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Movie for the transmission evolution of HG beams in the FSE with two dimensions under α=1 when β=1

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Movie for the transmission evolution of HG beams in the FSE with two dimensions under β=6 when α=

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Movie for the transmission evolution of HG beams in the FSE with two dimensions under β=-6 when α=

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Movie for the transmission evolution of HG beams in the FSE with two dimensions under β=0.6 when α=