Abstract Active metasurfaces, in which the optical property of a metasurface device can be controlled by external stimuli, have attracted great research interest recently. For optical switching and modulation applications, high-performance active metasurfaces need to show high transparency, high power efficiency, as well as ultrafast switching and large-scale fabrication capability. This paper reports Au/VO2-based active metasurfaces meeting the requirements above. Centimeter-scale Au/VO2 metasurfaces are fabricated by polystyrene sphere colloidal crystal self-assembly. The devices show optical modulation on-off ratio up to 12.7 dB and insertion loss down to 3.3 dB at 2200 nm wavelength in the static heating experiment, and ΔT/T of 10% in ultrafast pump-probe experiments. In particular, by judiciously aligning the surface plasmon resonance wavelength to the pump wavelength of the femtosecond laser, the enhanced electric field at 800 nm is capable to switch off the extraordinary optical transmission effect at 2200 nm in 100 fs time scale. Compared to VO2 thin-film samples, the devices also show 50% power reduction for all-optical modulation. Our work provides a practical way to fabricate large-scale and power-efficient active metasurfaces for ultrafast optical modulation.

中文翻译：

---

用于超快光调制的大规模、节能的 Au/VO2 活性超表面

摘要 有源超表面，其中超表面器件的光学特性可以由外部刺激控制，最近引起了极大的研究兴趣。对于光开关和调制应用，高性能有源超表面需要表现出高透明度、高功率效率以及超快开关和大规模制造能力。本文报告了满足上述要求的基于 Au/VO2 的活性超表面。厘米级 Au/VO2 超表面由聚苯乙烯球胶体晶体自组装制成。在静态加热实验中，这些器件在 2200 nm 波长处的光调制开关比高达 12.7 dB，插入损耗低至 3.3 dB，在超快泵浦探针实验中，ΔT/T 为 10%。特别是，通过明智地将表面等离子体共振波长与飞秒激光器的泵浦波长对齐，800 nm 处的增强电场能够在 100 fs 时间尺度内关闭 2200 nm 处的非凡光传输效应。与 VO2 薄膜样品相比，这些器件的全光调制功率也降低了 50%。我们的工作提供了一种实用的方法来制造用于超快光学调制的大规模和节能的有源超表面。