Non-orthogonal polarization multiplexed metasurfaces for tri-channel polychromatic image displays and information encryption

Abstract

Interference usually occurs between two non-orthogonally polarized light beams. Hence, metasurface enabled polarization multiplexing is generally conducted under two orthogonal polarization states to realize independent intensity and/or phase modulations. Herein, we show that polarization multiplexed metasurfaces can work under three non-orthogonal polarization states to realize tri-channel image displays with independent information encoding. Specifically, enabled by orientation degeneracy, each nanostructure of the metasurface operates with triple-manipulations of light, i.e., two channels for independent intensity manipulation under π/4 and 3π/8 linearly polarized (LP) light, respectively, and one channel for phase manipulation without polarization control. We experimentally demonstrate this concept by recording one continuous-brightness polychromatic image and one binary-brightness polychromatic image right at the metasurface plane, while a continuous-brightness polychromatic image is reconstructed in the far field, corresponding to three independent channels, respectively. More interestingly, in another design strategy with separated image encoding of two wavelengths, up to six independent image-display channels can be established and information delivery becomes safer by utilizing encryption algorithms. With the features of high information capacity and high security, the proposed meta-devices can empower advanced research and applications in multi-channel image displays, orbital angular momentum multiplexing communication, information encryption, anti-counterfeiting, multifunctional integrated nano-optoelectronics, etc.

Optical Magnetism‐Induced Dual Anisotropy in Dielectric Nanoantennas

“…In the phase-type anisotropy, although only one hologram is demonstrated in this work, it can also multiplex more holograms by using the orthogonal polarizations with the interleaved approach, [17] three-dimensional spatial images at multiple cut planes, [14,43,44] and color images with the wavelength-selected nanoantennas. [16] More importantly, to realize all these mentioned functionalities, our current configuration does not need the super-cell that contains multiple nanostructures in one diffraction cell, [35,[45][46][47] so that we can avoid the issues such as low contrast and signal-to-noise images, high diffraction orders due to the supercell larger than one wavelength.…”

“…Thus, high contrast between the image and the color-fixed background is obtained for both orthogonal-polarization illumination, which is not achievable for other demonstrations with the polarizationdependent backgrounds. [10][11]35] The hidden holographic image is recovered by shining a 633 nm-wavelength laser with circular polarization on the identical sample, so that we can observe the experimentally reconstructed "apple" pattern in a transmission mode (see its measurement system in Supporting Information). Figure 4f presents the measured image, which has great agreement with the simulated one (shown in the insert of Figure 4f).…”

Phase-change metasurfaces for dynamic image display and information encryption

“…Through precise design and layout of meta-atoms, the optical response of each meta-atom can be independently and completely controlled, enabling novel phenomena and functionalities for optical device applications such as nanoprinting, holography, flat lens, and vortex beam generators [7][8][9][10][11][12][13] . In the past few years, multifunctional metasurfaces designed to synchronously manipulate two or more properties are attracting enormous research interests due to the great potentials for increasing light integration and information capacity [14][15][16][17][18][19][20][21][22][23][24] . One prominent example is the combined nanoprinting holograms in a single metasurface design by simultaneously controlling the amplitude and phase of incident light at a desired wavelength, empowering advanced applications in information display and storage [25][26][27][28] .…”

Single-sized metasurface for simultaneous pseudo-color nanoprinting and holographic image display

“…Benefiting from the incomparable capability of manipulation for optical properties such as phase (Hao et al, 2021;Wang et al, 2021;Zhang H. et al, 2022;Cheng et al, 2022;Ma et al, 2022;Ming et al, 2022;Tao et al, 2022), polarization (Ouyang et al, 2021;Xu et al, 2021;Deng J. et al, 2022;Zhang S. et al, 2022;Kim et al, 2022; and amplitude Ren et al, 2021;Zheng et al, 2021;Deng L. et al, 2022;Yang et al, 2022), metasurface has emerged as a powerful platform for implementing multifunctional devices Chen et al, 2020;Dai et al, 2020;Li et al, 2020;Li J. et al, 2021). By dividing the metasurface into different parts, the segmenting metasurfaces have showcased their ability to integrate different functions, e.g., imaging and nanoprinting (Chen et al, 2020) or near-and far-field display together (Dai et al, 2020).…”