Angular‐Encrypted Quad‐Fold Display of Nanoprinting and Meta‐Holography for Optical Information Storage

Abstract

to control light waves across the entire spectral range and enable various optical applications and functionalities, including optical cloaking, [9,10] plasmonic coloring, [11] wavefront shaping, [12][13][14][15] meta-lenses, [16,17] meta-holography, [18][19][20][21][22][23] etc.Due to its compact scale and programmable versatility, more recent endeavors on metasurface have demonstrated to make it a competitive candidate for optical information encryption and storage. [1][2][3][4][5][6][7][8] For instance, by encoding the spectral amplitude/phase response, nanoprinting [24,25] /holography [18][19][20][21][22][23] graphs and encryption have been created to exhibit high-resolution displays, which are attainable under microscopes or projected on an optical screen. Other attempts have also been made to successfully enable the simultaneous multiplexing channels of both nanoprinting and metaholography. [26][27][28][29][30][31] Essentially, the typical strategy for storage capacity enhancement is to expand the multiplexing channels with independent encoding freedom. So far, the majority of controllable optical parameters have been extensively explored and created for multiplexing functionality, such as wavelength, [32,33] polarization, [34,35] OAM, [36] and forward/backward illumination direction, [37] etc.Despite these progressive new degrees of freedom, one of the most critical parameters in optics, the incident wave vector (k) direction, namely, the illumination angle, has not been fully exploited for optical encryption multiplexing. [38,39] Most of the previous optical multiplexing performances were under a fixed illumination angle. Usually, if the incident angle changes, the original optical performance cannot sustain to display any meaningful optical signature due to the lack of effective independent-encoding freedom under different illumination angles. Recent work by Kamali et al. [38] has demonstrated angularmultiplexed holography as dual-channel phase performance in the IR regime. However, unfolding the multiplexing functionalities in both phase and amplitude and creating a further degree of freedom remains not fully explored. Therefore, it remains a great challenge and a significant promise to achieve angularencrypted metasurface to exhibit both nanoprinting and metaholography with multi-channel independent-programmable freedom under arbitrary illumination angles.In this article, we propose an angular-encrypted metasurface with quad-fold optical display functionalities to store

Humidity‐Responsive RGB‐Pixels via Swelling of 3D Nanoimprinted Polyvinyl Alcohol

“…Considering that F–P etalons have been steadily exploited for encryption devices working at visible frequencies, our humidity‐responsive F–P etalons are a promising candidate for designing functional displays within the field of metaphotonics. [ 52 , 53 , 54 , 55 ] We believe that our approach will help expand the degrees of freedom of conventional tunable F–P applications.…”

Metasurface-based nanoprinting: principle, design and advances

“…Particularly, they designed three angular-multiplexing metasurfaces, including angular-multiplexed holography, angular-multiplexed nanoprinting, and a hybridized nanoprinting with holography. Furthermore, Wan et al proposed an electric-driven liquid-crystal-integrated metasurface (ELIM) integrating nanoprinting and holography and demonstrated toward advanced intelligent dynamic display 217 . By elaborately scanning the geometry of amorphous silicon (α-Si) nanopillar to build up a systematic architectural dictionary, spatial-multiplexing and the degeneracy for amplitude/phase selections are successfully achieved, thus realizing any arbitrary multi-field (both near-and far-field) encryptions.…”

“…216 , (e) ref. 217 , John Wiley and Sons. 220 , which is composed of Mg/ titanium (Ti)/palladium (Pd) film, hydrogen silsesquioxane (HSQ) layer, a silicon dioxide (SiO 2 ) film and an Ag mirror.…”

Toward Water‐Immersion Programmable Meta‐Display

“…[11] On the other hand, the far-field display of meta-holography [16][17][18][19][20][21][22][23][24] conquers the limitations of traditional diffractive optical elements (DOE) and achieves powerful multiplexing capability with multi-channels (>2-8), [18][19][20] highefficiency (>90%), [17] and large viewing-angle (>120°). [24] With such unique potential and excellent performance, meta-display makes a critical leap toward advanced display applications, including virtual/augmented reality (VR/AR), [19] information storage/encryption, [20,21] and anticounterfeiting displays. [14] Heading toward the next-generation intelligent display, the practical tuning capability for meta-device is critical for its wide application in real-life scenarios.…”