论文标题
将热扫描探针和相变材料结合的潜力
The Potential of Combining Thermal Scanning Probes and Phase-Change Materials for Tunable Metasurfaces
论文作者
论文摘要
元时间允许光波前振幅,相位和极化的时空变化。元时间的主动可调性的实现有望使可重新配置波前塑形的紧凑型扁平光学器件。相变材料(PCM),例如牙也渗出胚层或锗牙脲,是一个突出的材料类,由于结构过渡时的折射率变化很大,因此可以重新配置的跨面积。但是,通常使用激光诱导的PCMS开关限制了可实现的特征大小,因此限制了设备小型化。在这里,我们提出了热扫描探针诱导的晶橄榄胶体的局部切换,以实现近红外的跨额叶,其特征尺寸远低于衍射限制的光学开关可实现的范围。我们的设计基于平面多层堆栈,不需要在文献中常用的介电或金属谐振器制造突出的介电或金属谐振器。取而代之的是,我们从数值上证明,可以通过PCM层的局部和受控的尖端诱导的结晶来实现完美吸收的广泛带调整。使用简单的共振模式分析和数值模拟来解释元表面的光谱响应。为了促进实验实现,我们提供了使用多物理模拟的尖端诱导的结晶的详细理论描述,以证明制造紧凑的可重新配置的跨膜的巨大潜力。我们的概念允许可调的完美吸收,不仅可以用于热成像或感应,还可以应用于空间频率过滤。
Metasurfaces allow for the spatiotemporal variation of amplitude, phase, and polarization of optical wavefronts. Implementation of active tunability of metasurfaces promises compact flat optics capable of reconfigurable wavefront shaping. Phase-change materials (PCMs), such as germanium telluride or germanium antimony telluride, are a prominent material class enabling reconfigurable metasurfaces due to their large refractive index change upon structural transition. However, commonly employed laser-induced switching of PCMs limits the achievable feature sizes and thus, restricts device miniaturization. Here, we propose thermal scanning-probe-induced local switching of germanium telluride to realize near-infrared metasurfaces with feature sizes far below what is achievable with diffraction-limited optical switching. Our design is based on a planar multilayer stack and does not require fabrication of protruding dielectric or metallic resonators as commonly applied in the literature. Instead, we numerically demonstrate that a broad-band tuning of perfect absorption could be realized by the localized and controlled tip-induced crystallization of the PCM layer. The spectral response of the metasurface is explained using simple resonance mode analysis and numerical simulations. To facilitate experimental realization, we provide a detailed theoretical description of the tip-induced crystallization employing multiphysics simulations to demonstrate the great potential for fabricating compact reconfigurable metasurfaces. Our concept allows for tunable perfect absorption and can be applied not only for thermal imaging or sensing, but also for spatial frequency filtering.