Tunable narrowband spectral filtering across arbitrary optical wavebands is highly desirable in a plethora of applications, from chemical sensing and hyperspectral imaging to infrared astronomy. Yet, the ability to reconfigure the optical properties, with full reversibility, of a solid-state large-area narrowband filter remains elusive. Existing solutions require either moving parts, have slow response times, or provide limited spectral coverage. Here, we demonstrate a 1-inch diameter continuously tunable, fully reversible, all-solid-state, narrowband phase-change metasurface filter based on a GeSbTe-225 (GST)-embedded plasmonic nanohole array. The passband of the presented device is ${\sim}74\;{\rm{nm}}$ with ${\sim}70\%$ transmittance and operates across the 3–5 µm thermal imaging waveband. Continuous, reconfigurable tuning is achieved by exploiting intermediate GST phases via optical switching with a single nanosecond laser pulse, and material stability is verified through multiple switching cycles. We further demonstrate multispectral thermal imaging in the mid-wave infrared using our active phase-change metasurfaces. Our results pave the way for highly functional, reduced power, compact hyperspectral imaging systems and customizable optical filters for real-world system integration.

中文翻译：

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用于中波红外成像的 GeSbTe 相变超表面光谱滤波器的可逆光学调谐


从化学传感、高光谱成像到红外天文学，在众多应用中，跨任意光波段的可调谐窄带光谱滤波是非常理想的。然而，以完全可逆性重新配置固态大面积窄带滤光片的光学特性的能力仍然难以实现。现有的解决方案要么需要移动部件，要么响应时间慢，要么提供有限的光谱覆盖范围。在这里，我们展示了一种基于 GeSbTe-225 (GST) 嵌入式等离子体纳米孔阵列的 1 英寸直径连续可调、完全可逆、全固态、窄带相变超表面滤波器。该器件的通带为${\sim}74\;{\rm{nm}}$，透射率为${\sim}70\%$ ，并在 3–5 µm 热成像波段工作。通过使用单个纳秒激光脉冲进行光学切换，利用中间 GST 相位，实现连续、可重新配置的调谐，并通过多个切换周期验证材料稳定性。我们使用我们的主动相变超表面进一步演示了中波红外中的多光谱热成像。我们的研究成果为实现高性能、低功耗、紧凑型高光谱成像系统和可定制光学滤波器以实现实际系统集成铺平了道路。