Single‐Cell‐Driven Tri‐Channel Encryption Meta‐Displays

Abstract

Multi‐functional metasurfaces have attracted great attention due to the significant possibilities to realize highly integrated and ultra‐compact meta‐devices. Merging nano‐printing and holographic information multiplexing is one of the effective ways to achieve multi‐functionality, and such a merger can increase the information encoding capacity. However, the current approaches rely on stacking layers and interleaving, where multiple resonators effectively combine different functionalities on the cost of efficiency, design complexity, and challenging fabrication. To address such challenges, a single meta‐nanoresonator‐based tri‐functional metasurface is proposed by combining the geometric phase‐based spin‐decoupling and Malus's law intensity modulation. The proposed strategy effectively improves information capacity owing to the orientation degeneracy of spin‐decoupling rather than layer stacking or super‐cell designs. To validate the proposed strategy, a metasurface demonstrating two helicity‐dependent holographic outputs is presented in far‐field, whereas a continuous nano‐printing image is in near‐field. It is also employed on CMOS‐compatible and cost‐effective hydrogen amorphous silicon providing transparent responses for the whole visible band. As a result, the proposed metasurface has high transmission efficiency in the visible regime and verifies the design strategy without adding extra complexities to conventional nano‐pillar geometry. Therefore, the proposed metasurface opens new avenues in multi‐functional meta‐devices design and has promising applications in anti‐counterfeiting, optical storage and displays.​

Application of machine-learning techniques for characteristic analysis of refractory materials

“…In the original format, the shape of images is taken as a three channel input with vector size of (128, 128, 3). The shape of image against each channel is converted to 20 pixels by applying SVD for red, green, and blue, thereby generating a vector of size (1,60). Thus the problem becomes 63×500 dimensional for forward topology in case of each material.…”

“…Metasurface based designs have shown the potential for shaping the optical wavefronts by featuring only compact footprint in contrast to the bulky geometric optics [1][2][3][4][5][6][7][8][9]. The designs become capable of providing the control by engineering the geometry and size of meta-atom [9][10][11].…”

Polarization-Insensitive, Broadband, and Tunable Terahertz Absorber Using Slotted-Square Graphene Meta-Rings

“…etamaterials are artificially engineered materials containing sub-wavelength structures, which have become immensely popular due to their attributes such as negative refractive index [1,2], optical cloaking [3], imaging [4,5], polarization-conversion [6], optical reflectors [7,8], super-lensing [9], EM wave absorption [10,11], intelligent devices [12] [13,14] and analog computing [15], etc. The EM wave absorption characteristic of these artificial periodic structures is of particular interest due to its application in solar photovoltaics, radar cross-section reduction (RCSR), EM interference mitigation, multiple-input multiple-output (MIMO) antenna isolation, stealth technology, and other wireless communication systems [16][17][18].…”

Helicity multiplexed broadband meta-holography for ultraviolet regime

“…In advanced wavefront shaping, metasurfaces with extraordinary properties overcome conventional optics [1][2][3][4][5][6][7]. The manipulation of fundamental properties of electromagnetic (EM) waves with carefully engineered subwavelength nanostructures has attracted much attention [8][9][10][11][12][13][14]. Owing to this, metasurfaces have been demonstrated for various applications such as chiral meta-holography [15][16][17][18][19], meta-lensing [20][21][22][23][24], novel light structuring [25][26][27][28], integrated circuits [29,30] and antennas [31,32] etc.…”