Xu Ziquan, Luo Hao, Zhu Huanzheng, Hong Yu, Shen Weidong, Ding Jianping, Kaur Sandeep, Ghosh Pintu, Qiu Min, Li Qiang
State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou 310027, China.
Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province, School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou 310024, China.
Nano Lett. 2021 Jun 23;21(12):5269-5276. doi: 10.1021/acs.nanolett.1c01396. Epub 2021 Jun 2.
Control of thermal emission underpins fundamental science, as it is related to both heat and infrared electromagnetic wave transport. However, realizing nonvolatile reconfigurable thermal emission is challenging due to the inherent complexity or limitation in conventional radiative materials or structures. Here, we experimentally demonstrate a nonvolatile optically reconfigurable mid-infrared coding radiative metasurface. By applying laser pulses, infrared emissive patterns are directly encoded into an ultrathin (∼25 nm) GeSbTe layer integrated into a planar optical cavity with the optically crystallized GeSbTe spots, and the peak spectral emissivity is repeatedly switched between low (∼0.1) and high (∼0.7) values. In addition, the visible scattering patterns are independently modulated with submicron-sized bumps generated by high-power laser pulses. An anticounterfeiting label is demonstrated with spatially different infrared emission and visible light scattering information encoded. This approach constitutes a new route toward thermal emission control and has broad applications in encryption, camouflage, and so on.
热发射控制是基础科学的关键，因为它与热和红外电磁波传输都相关。然而，由于传统辐射材料或结构固有的复杂性或局限性，实现非易失性可重构热发射具有挑战性。在此，我们通过实验展示了一种非易失性光学可重构中红外编码辐射超表面。通过施加激光脉冲，红外发射图案被直接编码到集成在平面光学腔中的超薄（约25纳米）GeSbTe层中，形成光学结晶的GeSbTe斑点，并且峰值光谱发射率在低（约0.1）和高（约0.7）值之间反复切换。此外，可见散射图案由高功率激光脉冲产生的亚微米级凸起独立调制。展示了一种带有空间上不同的红外发射和可见光散射信息编码的防伪标签。这种方法构成了热发射控制的新途径，在加密、伪装等方面具有广泛应用。
