Non-volatile temperature-induced structural phase transitions such as those found in chalcogenide glasses are known to lead to strong changes in optical properties and are widely used in rewritable optical disk technology. Herein, we demonstrate that thermally activated optical memory can be achieved via the nanostructural reconfiguration of a metallic nanowire metamaterial array made from a shape-memory alloy: A nickel-titanium film of nanoscale thickness structured on the subwavelength scale exhibits bistability of its optical properties upon temperature cycling between 30 °C and 210 °C. The structure, comprising an array of NiTi nanowires coated with a thin film of gold to enhance its plasmonic properties, can exist in two non-volatile states presenting an optical reflectivity differential of 12% via nanoscale mutual displacements of alternating nanowires in the structure. Such all-metal shape-memory photonic gratings and metamaterials may find applications in bistable optical devices.Non-volatile temperature-induced structural phase transitions such as those found in chalcogenide glasses are known to lead to strong changes in optical properties and are widely used in rewritable optical disk technology. Herein, we demonstrate that thermally activated optical memory can be achieved via the nanostructural reconfiguration of a metallic nanowire metamaterial array made from a shape-memory alloy: A nickel-titanium film of nanoscale thickness structured on the subwavelength scale exhibits bistability of its optical properties upon temperature cycling between 30 °C and 210 °C. The structure, comprising an array of NiTi nanowires coated with a thin film of gold to enhance its plasmonic properties, can exist in two non-volatile states presenting an optical reflectivity differential of 12% via nanoscale mutual displacements of alternating nanowires in the structure. Such all-metal shape-memory photonic gratings and metamaterials may find applications in bistable optical devices.

中文翻译：

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形状记忆纳米线超材料阵列的光学双稳定性

众所周知，非挥发性温度引起的结构相变（例如在硫属化物玻璃中发现的结构相变）会导致光学性质发生强烈变化，并广泛用于可重写光盘技术。在这里，我们证明了热激活的光学记忆可以通过由形状记忆合金制成的金属纳米线超材料阵列的纳米结构重构来实现：在亚波长尺度上结构化的纳米级厚度的镍钛薄膜表现出其光学特性的双稳态。温度在 30 °C 和 210 °C 之间循环。该结构由一系列镀有金薄膜的 NiTi 纳米线组成，以增强其等离子体特性，可以以两种非易失性状态存在，通过结构中交替纳米线的纳米级相互位移呈现 12% 的光学反射率差异。这种全金属形状记忆光子光栅和超材料可能会在双稳态光学器件中得到应用。 众所周知，硫属化物玻璃中的非易失性温度诱导结构相变会导致光学性能发生强烈变化，因此被广泛应用于可擦写光盘技术。在这里，我们证明了热激活的光学记忆可以通过由形状记忆合金制成的金属纳米线超材料阵列的纳米结构重构来实现：在亚波长尺度上构造的纳米级厚度的镍钛薄膜在 30°C 和 210°C 之间的温度循环时表现出其光学特性的双稳态。该结构包括一系列涂有金薄膜以增强其等离子体特性的 NiTi 纳米线，可以以两种非挥发性状态存在，通过结构中交替纳米线的纳米级相互位移呈现 12% 的光学反射率差异。这种全金属形状记忆光子光栅和超材料可能会在双稳态光学器件中得到应用。可以以两种非易失性状态存在，通过结构中交替纳米线的纳米级相互位移呈现 12% 的光学反射率差异。这种全金属形状记忆光子光栅和超材料可能会在双稳态光学器件中得到应用。可以以两种非易失性状态存在，通过结构中交替纳米线的纳米级相互位移呈现 12% 的光学反射率差异。这种全金属形状记忆光子光栅和超材料可能会在双稳态光学器件中得到应用。