Dual‐Color Flexible Metasurfaces with Polarization‐Tunable Plasmons in Gold Nanorod Arrays

Abstract

Optical metasurfaces have attracted growing attention in plasmonic structural color in recent years due to their supreme performance in display and imaging technologies. However, real‐life applications of optical metasurfaces so far are often hindered by their complex, expensive, and time‐consuming nanofabrication methods, as well as sophisticated optical measurement systems. Herein, a flexible metasurface filter, based on periodic gold nanorods, capable of changing the output color by simple rotation of a linear polarizer is proposed and demonstrated. This phenomenon is enabled by switching of resonance plasmons in the gold nanorods with the polarization of incident light. Subsequent rotation of the input polarizer leads to an output of two distinct colors and their combinations. Moreover, metasurfaces consisting of Au nanorods with different orientations are integrated into a single flexible substrate. Information can be therefore encoded into the orientations of Au nanorods and readily decoded with the color of the metasurface under polarized illumination of white light‐emitting diode without complex optical components.

Template‐Electrodeposited Plasmonic Metasurfaces for High‐Sensitivity Biomolecular Detection

“…The reusable electrodeposition templates were fabricated by combining nanoimprint lithography, electrodeposition, and nanotransfer printing, modified from our previous publication (Figure 1a-f). [53] An ITO glass substrate was first magnetron sputtered with a 150 nm thickness silicon dioxide as the mask layer for electrodeposition. A nickel etching mask with 1200 nm period hexagonal nanocylinder array in a thin polyvinyl acrylic (PVA) intermediate film fabricated through nanoimprint lithography and electrodeposition was then electrostatically attached on the silicon dioxide covered ITO glass (Figure 1a).…”

Angular Multiplexing Nanoprinting with Independent Amplitude Encryption Based on Visible-Frequency Metasurfaces

“…Notably, the recent invention of a metasurface, a two-dimensional (2D) planar photonic element with subwavelength resolution, has emerged with the development of modern optics and nanophotonics. , Due to its unique optical properties, a plethora of significant applications have been realized based on metasurfaces, ranging from structural color, , holography, − to perfect absorbers, , sensors, metalens, , cloaking, , anomalous deflectors, etc. Besides these functionalities, metasurfaces also have been proposed and demonstrated with the breakthrough in imaging multiplexing and super-resolution enhancement to achieve nanoscale printing techniques for information encryption, − optical storage, and stereoscopic displays. , Various degrees of freedom in multiplexing strategies, including polarization multiplexing, − wavelength multiplexing, − wavevector forward/backward multiplexing (Janus metasurface), etc., have been extensively studied and demonstrated. Among these multiplexing schemes, angular incidence multiplexing is another facile approach to generate display images.…”

Electrically Switchable, Polarization-Sensitive Encryption Based on Aluminum Nanoaperture Arrays Integrated with Polymer-Dispersed Liquid Crystals

“…[8][9][10][11] However, this technique is often limited to a static single channel, which is controlled by the opto-geometrical parameters of both the meta-atoms and the surrounding media. Some efforts have been made to overcome this limit including polarization-sensitive nanostructures, [12][13][14][15][16][17][18][19] and stimuli-responsive composite systems. [20][21][22][23][24][25][26][27][28] These reported works always manifest complementary dual-images or embedded information in another form.…”

“…[20][21][22][23][24][25][26][27][28] These reported works always manifest complementary dual-images or embedded information in another form. 15,19,20,24 Anisotropic nanostructures play a key role in realizing the abovementioned functions. However, anisotropic nanoapertures and nanoantennas usually produce significant differences in coloration.…”

“…Along this line, advanced optical encryption and identification techniques, such as metasurface-based holographic images and structural colorations, have been extensively studied to overcome the limitations of traditional anticounterfeiting approaches. − Metasurfaces provide an unprecedented platform to manipulate the light field either spatially or temporally, including amplitude, phase, polarization, wavelength, etc. − Metasurface-enabled structural coloration, originating from light interaction with nanostructures, can revive the minutia with high accuracy. − However, this technique is often limited to a static single channel, which is controlled by the opto-geometrical parameters of both the meta-atoms and the surrounding media. Some efforts have been made to overcome this limit including polarization-sensitive nanostructures − and stimuli-responsive composite systems. − These reported works always manifest complementary dual-images or embedded information in another form. ,,, Anisotropic nanostructures play a key role in realizing the above-mentioned functions. However, anisotropic nanoapertures and nanoantennas usually produce significant differences in coloration.…”