A Triband Metasurface Covering Visible, Midwave Infrared, and Long-Wave Infrared for Optical Security
Qixiang Chen, Xuemei Huang, Zezhao Ju, Hongtao Lin, Huajie Tang, Chenyue Guo, Fan Fan, Xinyu Zhao, Yaoguang Ma, Yue Luo, Wei Li, Wenqi Zhong, Dongliang Zhao
Abstract
The independent manipulation of light across multiple wavelength bands provides new opportunities for optical security. Although dual-band optical encryption methods in the visible (VIS) and infrared bands have been developed, achieving synchronized and synergistic optical security across the VIS, midwave infrared (MWIR), and long-wave infrared (LWIR) bands remains a significant challenge. Here, we experimentally demonstrate a triband metasurface that covers the VIS, MWIR, and LWIR bands. While VIS imaging is achieved by structural color, MWIR, and LWIR imaging are achieved by selective emissivity structures, with MWIR/LWIR emissivities in the MWIR imaging region of 0.81/0.17, and in the LWIR imaging region of 0.21/0.83. Importantly, the MWIR and LWIR information is completely hidden in the VIS band. We also validate the ability of metasurface to encode complex information and information-misleading encryption. This work introduces new approaches for enhancing optical security and holds significant potential for applications such as anticounterfeiting and thermal camouflage.