Phase gradient metasurfaces have revolutionized modern optical components by significantly reducing the path length of bulk optics while maintaining high performance. However, their geometric design makes dynamic modulation challenging, with devices facing a trade-off between the modulation range and efficiency. Here, we introduce Silicon-on-Lithium Niobate (LNO) high-Quality-factor (high-Q) metasurfaces for efficient electro-optic wavefront shaping and modulation. Periodic perturbations within Si metasurface elements allow incident light to be weakly coupled into guided modes, generating high-Q resonances that manifest in the far-field diffraction spectrum. The near field of each Si element spatially overlaps with the LNO substrate, enabling electrically tunable modulation of the resonant frequency. Using full-field simulations, we demonstrate near-infrared, dynamically tunable beamsteering, and beamsplitting metasurfaces. First, we demonstrate beamsteering metasurfaces whose +1st order diffracted intensity can be modulated from 70% to 7% absolute efficiency near the resonant frequency with applied electric fields of order V/μm. Next, we design a tunable beam splitter, switching between direct, 0th order transmission and beamsplitting with the application of 30 V across the metasurface. Our high-Q electro-optic metasurfaces provide a foundation for efficient, time-dependent transfer functions in subwavelength footprints.

中文翻译：

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具有谐振电光相位梯度超表面的波前整形和调制

相梯度超表面通过在保持高性能的同时显着减少体光学的路径长度，彻底改变了现代光学组件。但是，它们的几何设计使动态调制具有挑战性，而器件则面临着调制范围和效率之间的折衷。在这里，我们介绍了铌酸锂硅（LNO）高质量因子（high-Q）超颖表面，以实现有效的电光波阵面成形和调制。Si超表面元素内部的周期性扰动使入射光弱耦合到引导模式，从而产生高Q共振，该共振表现在远场衍射光谱中。每个Si元素的近场在空间上与LNO衬底重叠，从而实现谐振频率的电可调调制。使用全场模拟 我们演示了近红外，动态可调的波束控制和分束超颖表面。首先，我们证明了在带V / v电场的情况下，在共振频率附近，+ 1阶衍射强度的射束转向超表面的绝对效率可以从70％调整为7％。μ微米。接下来，我们设计可调谐分束器，通过在超表面上施加30 V电压，在直接，零阶传输和分束之间切换。我们的高Q电光学超表面为亚波长足迹中高效，与时间相关的传递函数奠定了基础。