Plasmonic metasurfaces act as appealing platforms for flexible and accurate wave regulation, but their functionalities in wavefront or spectral tuning are settled upon manufactured. So the ability to dynamically tailor the amplitude, phase or polarization is highly desirable for many scenarios of micro & nano photonics and the integrated optoelectronics. Here, one type of plasmonic metasurface devices for active wavefront control is demonstrated in the mid-infrared regime. Fundamentally, the switchable and tunable lensing is exemplified by phase change of refractive index and the generalized Snell’s law as well as the Pancharatnam-Berry phase. As a proof of concept, the metal-insulator (MI) and metal-insulator-metal (MIM) architectures are employed with the phase change medium and an optimized energy conversion efficiency of cross polarization. In a wide spectral range between 2.8 μ m and 3.8 μ m, the reflective beam focuses with a cross-polarization efficiency o...

中文翻译：

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用于动态波前控制的相变感应有源超表面装置

等离子超表面充当了灵活而准确的波调节的吸引力平台，但是它们在波前或光谱调谐方面的功能已经确定。因此，动态调整幅度，相位或偏振的能力对于微米和纳米光子学以及集成光电子学的许多情况来说是非常需要的。在此，在中红外条件下证明了一种用于主动波前控制的等离子超表面装置。从根本上说，可切换和可调透镜是折射率的相变和广义斯涅尔定律以及Pancharatnam-Berry相的例证。作为概念验证，金属绝缘体（MI）和金属绝缘体金属（MIM）体系结构与相变介质和交叉极化的最佳能量转换效率一起使用。