Plasmonic metasurfaces with 42.3% transmission efficiency in the visible

Abstract

Metasurfaces are two-dimensional nanoantenna arrays that can control the propagation of light at will. In particular, plasmonic metasurfaces feature ultrathin thicknesses, ease of fabrication, field confinement beyond the diffraction limit, superior nonlinear properties, and ultrafast performances. However, the technological relevance of plasmonic metasurfaces operating in the transmission mode at optical frequencies is questionable due to their limited efficiency. The state-of-the-art efficiency of geometric plasmonic metasurfaces at visible and near-infrared frequencies, for example, is ≤10%. Here, we report a multipole-interference-based transmission-type geometric plasmonic metasurface with a polarization conversion efficiency that reaches 42.3% at 744 nm, over 400% increase over the state of the art. The efficiency is augmented by breaking the scattering symmetry due to simultaneously approaching the generalized Kerker condition for two orthogonal polarizations. In addition, the design of the metasurface proposed in this study introduces an air gap between the antennas and the surrounding media that confines the field within the gap, which mitigates the crosstalk between meta-atoms and minimizes metallic absorption. The proposed metasurface is broadband, versatile, easy to fabricate, and highly tolerant to fabrication errors. We highlight the technological relevance of our plasmonic metasurface by demonstrating a transmission-type beam deflector and hologram with record efficiencies.

Cavity-enhanced metallic metalens with improved Efficiency

“…Thus, we have confidence that the existence of the cavity in the BLM rightly contribute to the improvement of the working efficiencies. It should be mentioned that in a recently published work 33 , a similar type of bilayer plasmonic metasurface was proposed and show a greatly improved efficiency. However, it is recognized from the viewpoint of interference scattering of multipolar meta-atom without any discussion on the cavity effect.…”

Diffractive metalens: from fundamentals, practical applications to current trends

“…As shown in Figure 3(b), each of the layers (composed of three different metals: gold, silver, and aluminum) servers as a narrow band Fresnel binary zone plate, and the three zone plates were designed with the same focal length [109]. Such few-layer metasurfaces have been widely investigated recently due to the abundant interlayer interactions and the feasible fabrication processes [52,[110][111][112][113][114][115]. Since the required phase compensation lies in a wide range, the achromatic metalens working in a wide bandwidth is not easy to realize [116][117][118][119].…”

Plasmonic Photocatalysts for Sunlight‐Driven Reduction of CO2: Details, Developments, and Perspectives

“…Such a system is built by depositing plasmonic nanostructures onto a semiconductor. The adequately designed architecture allows the formation of LSPR, which induces a wide wavelength range for excellent light absorption with an absorption efficiency up to 42.3 % . The LSPR simultaneously generates highly energetic electrons and facilitates their fast and efficient transfer to the nearby semiconductor, which can reach an efficiency of 45 % .…”