Switchable polarization selectivity in reconfigurable metasurfaces is highly required in the field of information encryption. In this paper, we proposed a scheme of information encryption by using the giant and strength-switchable circular dichroism (CD) in VO-based chiral metasurfaces in the mid-infrared region. A bar code information is encrypted and hidden into a VO-based bielliptic cylinder (BC) and bielliptic cylinder enantiomer (BCE) constructed array. The metallic VO-based BC and BCE arrays with the rotation angles () exhibit opposite CD (−0.94/0.94) at 6330 nm. With the VO transition from metallic to insulator phase, the giant polarization selectivity of both BC and BCE arrays will disappear. Hence, only when the specific environment temperature (>68 °C) and polarization state of incident light (LCP) are simultaneously satisfied, the secret information could be decrypted. The reversible CD in VO-based chiral metasurfaces possesses great potentials for the application of optical information encryption.

中文翻译：

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基于二氧化钒的手性超表面中强度可切换圆二色性驱动的信息加密

在信息加密领域非常需要可重构超表面中的可切换偏振选择性。在本文中，我们提出了一种利用中红外区域VO基手性超表面中巨大且强度可切换的圆二色性（CD）进行信息加密的方案。条形码信息被加密并隐藏在基于 VO 的双椭圆柱 (BC) 和双椭圆柱对映异构体 (BCE) 构造的阵列中。具有旋转角 () 的金属 VO 基 BC 和 BCE 阵列在 6330 nm 处表现出相反的 CD (-0.94/0.94)。随着 VO 从金属相转变为绝缘体相，BC 和 BCE 阵列的巨大偏振选择性将消失。因此，只有同时满足特定的环境温度（>68℃）和入射光的偏振态（LCP），秘密信息才能被解密。基于VO的手性超表面中的可逆CD在光信息加密应用中具有巨大的潜力。