scholarly journals Near-zero reflection of all-dielectric structural coloration enabling polarization-sensitive optical encryption with enhanced switchability

Nanophotonics ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 919-926
Author(s):  
Chunghwan Jung ◽  
Younghwan Yang ◽  
Jaehyuck Jang ◽  
Trevon Badloe ◽  
Taejun Lee ◽  
...  
Keyword(s):  
Incident Light ◽  
Visible Spectrum ◽  
Qr Code ◽  
Structural Coloration ◽  
Optical Encryption ◽  
Full Color ◽  
Potential Applications ◽  
Color Spectrum ◽  
Color Printing ◽  
Security Information

AbstractStructural coloration using metasurfaces has been steadily researched to overcome the limitations of conventional color printing using pigments by improving the resolution, lowering the toxicity, and increasing the durability. Many metasurfaces have been demonstrated for dynamic structural coloration to convert images at the visible spectrum. However, the previous works cannot reach near-zero scattering when colors are turned-off, preventing it from being cryptographic applications. Herein, we propose a completely on/off switchable structural coloration with polarization-sensitive metasurfaces, enabling full-colored images to be displayed and hidden through the control of the polarization of incident light. It is confirmed that the nanostructure exhibits the polarization-dependent magnetic field distributions, and near-zero scattering is realized when the polarization of incident light is perpendicular to the long axis of the nanofins. Also, the metasurfaces are made up of triple-nanofin structures whose lengths affect locations of resonance peaks, resulting in full-color spectrum coverages. With such advantages, a QR code image, a two-color object image, and an overlapped dual-portrait image are obtained with the metasurfaces. Such demonstrations will provide potential applications in the fields of high-security information encryption, security tag, multichannel imaging, and dynamic displays.

scholarly journals Subwavelength sorting of full-color based on anti-Hermitian metasurfaces

Nanophotonics ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 967-974
Author(s):  
Seong Jun Kim ◽  
Changhyun Lee ◽  
Sangtae Jeon ◽  
Junghyun Park ◽  
Soo Jin Kim
Keyword(s):  
Optical Sensors ◽  
Detection System ◽  
Incident Light ◽  
Practical Interest ◽  
Target Position ◽  
Visible Spectrum ◽  
Color Filter ◽  
Full Color ◽  
Spectral Linewidth ◽  
Entire Visible Spectrum

AbstractSplitting the spectrum of incident light at nanoscale has been of great scientific and practical interest due to its potential application in various optical sensors. For many years, researchers have been striving to realize the full-color sorting of light at subwavelength scale, while keeping the loss of incident photons to a minimum. In this article, we present semiconductor-based metasurfaces that facilitate the efficient sorting of full-color by inducing anti-Hermitian coupling between multiple nanoantenna arrays. To achieve this, we first explore how the coherent interactions between maximally crafted nanoantennas in the metasurfaces can be effectively controlled by judiciously positioning them in both lateral and vertical directions, which leads to the switched coupling of light at each target position. Based on the analysis, we demonstrate a metasurface-based absorber that features efficient, spectropolarimetric detections over the entire visible spectrum, ranging from 470 to 630 nm. In addition, the metasurface detects relatively narrow spectral linewidth of 60 nm and shows the sensitivity up to 70%, which surpasses the previous works on subwavelength photon sorting or color filter-based detection system. We envision that our approach provides guidelines for realizing the metasurfaces with enhanced functionalities, that is the increase of spectral channels for detection in a given subwavelength-scaled unit cell.

scholarly journals Microfabrication and Surface Functionalization of Soda Lime Glass through Direct Laser Interference Patterning

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 129
Author(s):  
Marcos Soldera ◽  
Sabri Alamri ◽  
Paul Alexander Sürmann ◽  
Tim Kunze ◽  
Andrés Fabián Lasagni
Keyword(s):  
Laser Radiation ◽  
Surface Functionalization ◽  
Incident Light ◽  
Chemical Properties ◽  
Visible Spectrum ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
Textured Surfaces ◽  
Aspect Ratios ◽  
Direct Laser

All-purpose glasses are common in many established and emerging industries, such as microelectronics, photovoltaics, optical components, and biomedical devices due to their outstanding combination of mechanical, optical, thermal, and chemical properties. Surface functionalization through nano/micropatterning can further enhance glasses’ surface properties, expanding their applicability into new fields. Although laser structuring methods have been successfully employed on many absorbing materials, the processability of transparent materials with visible laser radiation has not been intensively studied, especially for producing structures smaller than 10 µm. Here, interference-based optical setups are used to directly pattern soda lime substrates through non-lineal absorption with ps-pulsed laser radiation in the visible spectrum. Line- and dot-like patterns are fabricated with spatial periods between 2.3 and 9.0 µm and aspect ratios up to 0.29. Furthermore, laser-induced periodic surface structures (LIPSS) with a feature size of approximately 300 nm are visible within these microstructures. The textured surfaces show significantly modified properties. Namely, the treated surfaces have an increased hydrophilic behavior, even reaching a super-hydrophilic state for some cases. In addition, the micropatterns act as relief diffraction gratings, which split incident light into diffraction modes. The process parameters were optimized to produce high-quality textures with super-hydrophilic properties and diffraction efficiencies above 30%.

scholarly journals Spatial multiplexing holographic combiner for glasses-free augmented reality

Nanophotonics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 3003-3010
Author(s):  
Jiacheng Shi ◽  
Wen Qiao ◽  
Jianyu Hua ◽  
Ruibin Li ◽  
Linsen Chen
Keyword(s):  
Augmented Reality ◽  
Large Scale ◽  
Motion Parallax ◽  
Visible Spectrum ◽  
Physical World ◽  
Spatial Multiplexing ◽  
White Balance ◽  
Full Color ◽  
Entire Visible Spectrum ◽  
3D Scene

AbstractGlasses-free augmented reality is of great interest by fusing virtual 3D images naturally with physical world without the aid of any wearable equipment. Here we propose a large-scale spatial multiplexing holographic see-through combiner for full-color 3D display. The pixelated metagratings with varied orientation and spatial frequency discretely reconstruct the propagating lightfield. The irradiance pattern of each view is tailored to form super Gaussian distribution with minimized crosstalk. What’s more, spatial multiplexing holographic combiner with customized aperture size is adopted for the white balance of virtually displayed full-color 3D scene. In a 32-inch prototype, 16 views form a smooth parallax with a viewing angle of 47°. A high transmission (>75%) over the entire visible spectrum range is achieved. We demonstrated that the displayed virtual 3D scene not only preserved natural motion parallax, but also mixed well with the natural objects. The potential applications of this study include education, communication, product design, advertisement, and head-up display.

Structural color printing: full color printing with single ink

2010 ◽  
Author(s):  
Hyoki Kim ◽  
Jianping Ge ◽  
Junhoi Kim ◽  
Sung-Eun Choi ◽  
Hosuk Lee ◽  
...  
Keyword(s):  
Structural Color ◽  
Full Color ◽  
Color Printing

Intense multi-state visible absorption and full-color luminescence of nitrogen-doped carbon quantum dots for blue-light-excitable solid-state-lighting

2016 ◽  
Vol 4 (38) ◽  
pp. 9027-9035 ◽  
Author(s):  
Daqin Chen ◽  
Weiwei Wu ◽  
Yongjun Yuan ◽  
Yang Zhou ◽  
Zhongyi Wan ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solid State ◽  
Carbon Quantum Dots ◽  
Solid State Lighting ◽  
Visible Absorption ◽  
Nitrogen Doped ◽  
Full Color ◽  
Potential Applications ◽  
Doped Carbon Dots ◽  
Nitrogen Doped Carbon

Nitrogen-doped carbon dots with multi-state visible absorption and full-color blue/yellow/red emissions are synthesized, and show potential applications in solid-state-lighting.

scholarly journals Reprogrammable meta-hologram for optical encryption

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Geyang Qu ◽  
Wenhong Yang ◽  
Qinghai Song ◽  
Yilin Liu ◽  
Cheng-Wei Qiu ◽  
...  
Keyword(s):  
Information Security ◽  
Degrees Of Freedom ◽  
Incident Light ◽  
Optical Information ◽  
Optical Encryption ◽  
Information Channels ◽  
Encryption And Authentication ◽  
Dielectric Metasurface ◽  
At Will

Abstract Meta-holographic encryption is a potentially important technique for information security. Despite rapid progresses in multi-tasked meta-holograms, the number of information channels available in metasurfaces is limited, making meta-holographic encryption vulnerable to some attacking algorithms. Herein, we demonstrate a re-programmable metasurface that can produce arbitrary holographic images for optical encryption. The encrypted information is divided into two matrices. These two matrices are imposed to the incident light and the metasurface, respectively. While the all-dielectric metasurface is static, the phase matrix of incident light provides additional degrees of freedom to precisely control the eventual functions at will. With a single Si metasurface, arbitrary holographic images and videos have been transported and decrypted. We hope that this work paves a more promising way to optical information encryption and authentication.

scholarly journals Metalenses Based on Symmetric Slab Waveguide and c-TiO2: Efficient Polarization-Insensitive Focusing at Visible Wavelengths

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 699 ◽  
Author(s):  
Yaoyao Liang ◽  
Zhongchao Wei ◽  
Jianping Guo ◽  
Faqiang Wang ◽  
Hongyun Meng ◽  
...  
Keyword(s):  
Berry Phase ◽  
Incident Light ◽  
Visible Spectrum ◽  
Slab Waveguide ◽  
Optical Elements ◽  
Polarization Insensitive ◽  
Wavefront Shaping ◽  
Visible Wavelengths ◽  
532 Nm ◽  
Good Agreement

A key goal of metalens research is to achieve wavefront shaping of light using optical elements with thicknesses on the order of the wavelength. Here we demonstrate ultrathin highly efficient crystalline titanium dioxide metalenses at blue, green, and red wavelengths (λ0 = 453 nm, 532 nm, and 633 nm, respectively) based on symmetric slab waveguide theory. These metalenses are less than 488 nm-thick and capable of focusing incident light into very symmetric diffraction-limited spots with strehl ratio and efficiency as high as 0.96 and 83%, respectively. Further quantitative characterizations about metalenses’ peak focusing intensities and focal spot sizes show good agreement with theoretical calculation. Besides, the metalenses suffer only about 10% chromatic deviation from the ideal spots in visible spectrum. In contrast with Pancharatnam–Berry phase mechanism, which limit their incident light at circular polarization, the proposed method enables metalenses polarization-insensitive to incident light.

Metal-Masked Mie-Resonant Full-Color Printing for Achieving Free-Space Resolution Limit

ACS Photonics ◽  
2018 ◽  
Vol 5 (9) ◽  
pp. 3849-3855 ◽  
Author(s):  
Yusuke Nagasaki ◽  
Ikuto Hotta ◽  
Masafumi Suzuki ◽  
Junichi Takahara
Keyword(s):  
Free Space ◽  
Resolution Limit ◽  
Space Resolution ◽  
Full Color ◽  
Color Printing

Design of Multi-Resonant Cavities Based on Metal-Coated Dielectric Nanocylinders

2018 ◽  
Vol 73 (6) ◽  
pp. 559-563 ◽  
Author(s):  
Junyuan Dong ◽  
Guanxia Yu ◽  
Jingjing Fu ◽  
Min Luo ◽  
Wenwen Du
Keyword(s):  
Cross Section ◽  
Optical Sensors ◽  
Incident Light ◽  
Resonant Cavities ◽  
Storage Devices ◽  
Symmetrical Distribution ◽  
Integrated Devices ◽  
Potential Applications ◽  
The Relationship ◽  
Transmission And Reflection

AbstractIn this paper, the light scattering properties for multiple silver-coated dielectric nanocylinders with the symmetrical distribution were investigated. Based on the transfer matrix method, we derive the general transmission and reflection coefficient matrices for multiple dielectric nanocylinders. When the incident light frequencies are less than the plasma frequencies, the surface plasmons (SPs) appear in the interface between the silver and dielectrics. Numerical simulations show that there are three peaks of absorption cross-section (ACS) in the relationship between the ACS and the frequencies of the incident light, when the distance between the silver-coated dielectric nanocylinders is chosen properly. These SPs resonance peaks are characterised as resonances intrinsic to the cylindrically periodic system corresponding to different inner cavity structures. These multi-resonant cavities may have potential applications in integrated devices, optical sensors and optical storage devices.

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