Large-Area Arrays of Quasi-3D Au Nanostructures for Polarization-Selective Mid-Infrared Metasurfaces
Large-Area Arrays of Quasi-3D Au Nanostructures for Polarization-Selective Mid-Infrared Metasurfaces
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DOI：
10.1021/acsanm.0c01348
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发表时间：
2020-07-24
影响因子：
5.9
通讯作者：
Gracias, David H.
中科院分区：
文献类型：
--
作者：
Nagal, Vivek;Li, Tengfei;Gracias, David H.
超颖表面是二维图案，其用于通过控制特定波长处的所得透射率、反射率或吸收来操纵光的传播。超表面通常由布置在单层或多层中的金属或电介质组件组成，并且其尺寸显著小于入射光的波长。虽然在这些表面的设计方面已经取得了相当大的进展，但在大面积上进行高通量并行制造存在重大挑战，这限制了它们的适用性。在这里，我们展示了中红外超颖表面的设计和表征，使用相结合的照片和纳米压印光刻（NIL）。我们制造的阵列超过毫米级的各种三维纳米级的设计，包括不对称的脱节的形状和对称的手风琴状的形状，宽度为400-600 nm，厚度为30-50 nm，长度为5-6 μ m。我们使用傅里叶变换红外（FTIR）显微镜在反射中表征这些超颖表面的中红外光学响应，并使用有限元法（FEM）计算模拟与实验之间具有良好的一致性的光谱响应。此外，我们表明，超颖表面表现出的特征和显着不同的等离子体共振模式的入射光的偏振的基础上。我们的大面积制造方法允许具有3D微米和纳米元件的大面积超颖表面的成本效益制造，用于可扩展的光子和等离子体器件，具有显著的几何和光学特性可调性。
Metasurfaces are two-dimensional patterns that are used to manipulate the propagation of light by controlling the resultant transmittance, reflectance, or absorption at specific wavelengths. Metasurfaces are typically composed of metallic or dielectric components arranged in single or multiple layers and with sizes significantly less than the wavelength of incident light. While considerable advances have been made in the design of these surfaces, there are significant challenges with high-throughput parallel fabrication over large areas which limits their applicability. Here, we demonstrate the design and characterization of mid-IR metasurfaces fabricated using a combination of photo and nanoimprint lithography (NIL). We fabricate arrays over millimeter scales with a variety of 3D nanoscale designs including asymmetric disjointed shapes and symmetric accordion-like shapes with widths of 400-600 nm, thicknesses of 30-50 nm, and lengths of 5-6 mu m. We characterize the mid-IR optical response of these metasurfaces in reflection using Fourier transform infrared (FTIR) microscopy, and simulate the spectral response using finite element method (FEM) calculations with good agreement between simulations and experiments. Also, we demonstrate that the metasurfaces exhibit characteristic and significantly different plasmonic resonance modes based on the polarization of the incoming light. Our large-area fabrication methodology allows cost-effective manufacturing of large-area metasurfaces with 3D micro- and nanoelements for scalable photonic and plasmonic devices with significant tunability in geometry and optical characteristics.