Three-dimensional plasmonic stereoscopic prints in full colour

Abstract

Metal nanostructures can be designed to scatter different colours depending on the polarization of the incident light. Such spectral control is attractive for applications such as high-density optical storage, but challenges remain in creating microprints with a single-layer architecture that simultaneously enables full-spectral and polarization control of the scattered light. Here we demonstrate independently tunable biaxial colour pixels composed of isolated nanoellipses or nanosquare dimers that can exhibit a full range of colours in reflection mode with linear polarization dependence. Effective polarization-sensitive full-colour prints are realized. With this, we encoded two colour images within the same area and further use this to achieve depth perception by realizing three-dimensional stereoscopic colour microprint. Coupled with the low cost and durability of aluminium as the functional material in our pixel design, such polarization-sensitive encoding can realize a wide spectrum of applications in colour displays, data storage and anti-counterfeiting technologies.

Plasmonic Color Filters as Dual‐State Nanopixels for High‐Density Microimage Encoding

“…Plasmonic particles and filters have also seen applications in these research areas, with the aforementioned image encoding examples having been joined by demonstrations of their use in optical data storage. [23,24,[35][36][37] Here, we show a new utilization of image encoding using polarization multiplexed plasmonic filters, where, unlike previous studies that employed color or position switching in fixed images, [14,38] we show that two arbitrary, full-color images can be encoded into a single array of pixels. Our individual pixels are comprised of asymmetric cross-shaped nanoapertures in a thin film of aluminum.…”

“…Individual pixels that can encode two color profiles allow for images which have dual color states [38,39] and stereoscopic properties. [14] Here, we show that it is possible to use a single array of cross-shaped apertures to encode two full-color images into the same unit area, using the same set of nanopixels. Figure 2 shows bright-field microscopy images of two distinct color patterns, each produced from the same pixel array.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12] Among these examples are color filters based on plasmonics; filters which rely on the resonant interaction between incident photo ns and the free-electrons of nanoscale metal structures. Thus far, filters based on positive nanostructures, [4,7,9,[11][12][13][14][15] filters based on cavity apertures, [2,[16][17][18] and filters which combine both strategies [8] have been shown, each with distinct fabrication and geometrical solutions to achieving color "nanopixels" for selective white-light separation. Plasmonic pixels, in their various forms, hold several advantages reactive ion etching, and inductively coupled plasma deposition).…”

Active Color Control in a Metasurface by Polarization Rotation

“…As an alternative, adoption of mechanical transformation [17][18][19][20][21], chemical transition [22][23][24], phase change material [25][26][27][28] and electrochromic polymer [29] provide dynamic color printing. Nevertheless, dynamic color printing can be realized in a far simpler system by polarization control without involving any external stimuli [30][31][32]. A periodic array of cross-shaped nanoantennas [8,[33][34][35], elliptical nanostructures [31,32,36], rectangle nanostructures [37] and a grating pattern [38] have demonstrated active color printing by rotating incident polarization.…”

“…Nevertheless, dynamic color printing can be realized in a far simpler system by polarization control without involving any external stimuli [30][31][32]. A periodic array of cross-shaped nanoantennas [8,[33][34][35], elliptical nanostructures [31,32,36], rectangle nanostructures [37] and a grating pattern [38] have demonstrated active color printing by rotating incident polarization. Here, lack of four-fold symmetry leads to active color generation.…”