Four-channel joint-polarization-frequency-multiplexing encryption meta-hologram based on dual-band polarization multiplexing meta-atoms

作者:Zhang, Qingyuan; Wang, Jingwen; Xie, Rensheng; Gu, Zhen; Zhang, Zhengping; Wang, Xiong; Zhang, Hualiang; Chen, Chang*; Chen, Weidong; Ding, Jun; Zhang, Xiang
来源:Optics Express, 2023, 31(11): 17569-17579.
DOI:10.1364/OE.487483

摘要

Holography is an advanced imaging technology where image information can be reconstructed without a lens. Recently, multiplexing techniques have been widely adapted to realize multiple holographic images or functionalities in a meta-hologram. In this work, a reflective four-channel meta-hologram is proposed to further increase the channel capacity by simultaneously implementing frequency and polarization multiplexing. Compared to the single multiplexing technique, the number of channels achieves a multiplicative growth of the two multiplexing techniques, as well as allowing meta-devices to possess cryptographic characteristics. Specifically, spin-selective functionalities for circular polarizations can be achieved at lower frequency, while different functionalities can be obtained at higher frequency under different linearly polarized incidences. As an illustrative example, a four-channel joint-polarizationfrequency-multiplexing meta-hologram is designed, fabricated, and characterized. The measured results agree well with the numerically calculated and full-wave simulated ones, which provides the proposed method with great potential in numerous opportunities such as multi-channel imaging and information encryption technology.