scholarly journals Polarization Volume Gratings for Near-Eye Displays and Novel Photonic Devices

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 561 ◽  
Author(s):  
Kun Yin ◽  
Tao Zhan ◽  
Jianghao Xiong ◽  
Ziqian He ◽  
Shin-Tson Wu
Keyword(s):  
Optical Properties ◽  
Review Paper ◽  
Berry Phase ◽  
Optical Axis ◽  
Optical Element ◽  
Photonic Devices ◽  
Volume Bragg Gratings ◽  
Strong Polarization ◽  
Diffraction Angle ◽  
Potential Applications

Liquid crystal-based reflective polarization volume grating (PVG), also known as a linear Bragg–Berry phase optical element or a member of volume Bragg gratings (VBGs), is a functional planar structure with patterned orientation of optical axis. Due to the strong polarization selectivity, nearly 100% diffraction efficiency, large diffraction angle, and simple fabrication process, PVGs have found potential applications in novel photonic devices and emerging near-eye displays. In this review paper, we describe the operation principles, discuss the optical properties, present the fabrication methods, and provide promising applications of PVGs for near-eye displays and novel photonic devices.

scholarly journals Theoretical Analysis of Terahertz Dielectric–Loaded Graphene Waveguide

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 210
Author(s):  
Da Teng ◽  
Kai Wang
Keyword(s):  
Photonic Devices ◽  
Effective Index ◽  
The Finite Element Method ◽  
Index Method ◽  
Modal Properties ◽  
Terahertz Region ◽  
Effective Index Method ◽  
Integration Density ◽  
Device Integration ◽  
Potential Applications

The waveguiding of terahertz surface plasmons by a GaAs strip-loaded graphene waveguide is investigated based on the effective-index method and the finite element method. Modal properties of the effective mode index, modal loss, and cut-off characteristics of higher order modes are investigated. By modulating the Fermi level, the modal properties of the fundamental mode could be adjusted. The accuracy of the effective-index method is verified by a comparison between the analytical results and numerical simulations. Besides the modal properties, the crosstalk between the adjacent waveguides, which determines the device integration density, is studied. The findings show that the effective-index method is highly valid for analyzing dielectric-loaded graphene plasmon waveguides in the terahertz region and may have potential applications in subwavelength tunable integrated photonic devices.

scholarly journals Achromatic terahertz Airy beam generation with dielectric metasurfaces

Nanophotonics ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Qingqing Cheng ◽  
Juncheng Wang ◽  
Ling Ma ◽  
Zhixiong Shen ◽  
Jing Zhang ◽  
...  
Keyword(s):  
Biomedical Imaging ◽  
Frequency Dispersion ◽  
Light Sheet ◽  
Photonic Devices ◽  
Self Healing ◽  
Beam Focusing ◽  
Light Sheet Microscopy ◽  
Airy Beam ◽  
Potential Applications ◽  
Airy Beams

AbstractAiry beams exhibit intriguing properties such as nonspreading, self-bending, and self-healing and have attracted considerable recent interest because of their many potential applications in photonics, such as to beam focusing, light-sheet microscopy, and biomedical imaging. However, previous approaches to generate Airy beams using photonic structures have suffered from severe chromatic problems arising from strong frequency dispersion of the scatterers. Here, we design and fabricate a metasurface composed of silicon posts for the frequency range 0.4–0.8 THz in transmission mode, and we experimentally demonstrate achromatic Airy beams exhibiting autofocusing properties. We further show numerically that a generated achromatic Airy-beam-based metalens exhibits self-healing properties that are immune to scattering by particles and that it also possesses a larger depth of focus than a traditional metalens. Our results pave the way to the realization of flat photonic devices for applications to noninvasive biomedical imaging and light-sheet microscopy, and we provide a numerical demonstration of a device protocol.

A New Type of Cuprous-Cysteamine Sensitizers: Synthesis, Optical Properties and Potential Applications

2021 ◽  
pp. 100435
Author(s):  
Yan Wang ◽  
Noura Dawas Alkhaldi ◽  
Nil Kanatha Pandey ◽  
Lalit Chudal ◽  
Lingyun Wang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Potential Applications ◽  
New Type

scholarly journals Enhancing the Optical Efficiency of Near-Eye Displays with Liquid Crystal Optics

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 107
Author(s):  
Tao Zhan ◽  
En-Lin Hsiang ◽  
Kun Li ◽  
Shin-Tson Wu
Keyword(s):  
Virtual Reality ◽  
Liquid Crystal ◽  
High Efficiency ◽  
Berry Phase ◽  
Optical Element ◽  
Liquid Crystal Polymer ◽  
Proof Of Concept ◽  
Optical Efficiency ◽  
Crystal Polymer ◽  
Light Efficiency

We demonstrate a light efficient virtual reality (VR) near-eye display (NED) design based on a directional display panel and a diffractive deflection film (DDF). The DDF was essentially a high-efficiency Pancharatnam-Berry phase optical element made of liquid crystal polymer. The essence of this design is directing most of the display light into the eyebox. The proposed method is applicable for both catadioptric and dioptric VR lenses. A proof-of-concept experiment was conducted with off-the-shelf optical parts, where the light efficiency was enhanced by more than 2 times.

scholarly journals Enhanced luminescence properties of Ca1+xSr2−xAl2O6:Eu3+ (0 ≤ x ≤ 1) red phosphors based on composition modulation

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12981-12989
Author(s):  
Biao Shen ◽  
Jianghang Xu ◽  
Qinan Mao ◽  
Jiasong Zhong
Keyword(s):  
Optical Properties ◽  
Quantum Efficiency ◽  
Luminescence Properties ◽  
Composition Modulation ◽  
Red Phosphors ◽  
Potential Applications ◽  
Enhanced Luminescence

A series of Ca1+xSr2−xAl2O6:Eu3+ (0 ≤ x ≤ 1) red-emitting phosphors with adjustable optical properties and excellent quantum efficiency was developed for potential applications in warm WLEDs.

scholarly journals Changes in Optical Properties upon Dye–Clay Interaction: Experimental Evaluation and Applications

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 197
Author(s):  
Giorgia Giovannini ◽  
René M. Rossi ◽  
Luciano F. Boesel
Keyword(s):  
Optical Properties ◽  
Hybrid Materials ◽  
High Performance ◽  
Fluorescent Properties ◽  
Chemical Mechanisms ◽  
Strong Electrostatic Interaction ◽  
Potential Applications ◽  
Photochemical Properties ◽  
Physical And Chemical ◽  
The Relationship

The development of hybrid materials with unique optical properties has been a challenge for the creation of high-performance composites. The improved photophysical and photochemical properties observed when fluorophores interact with clay minerals, as well as the accessibility and easy handling of such natural materials, make these nanocomposites attractive for designing novel optical hybrid materials. Here, we present a method of promoting this interaction by conjugating dyes with chitosan. The fluorescent properties of conjugated dye–montmorillonite (MMT) hybrids were similar to those of free dye–MMT hybrids. Moreover, we analyzed the relationship between the changes in optical properties of the dye interacting with clay and its structure and defined the physical and chemical mechanisms that take place upon dye–MMT interactions leading to the optical changes. Conjugation to chitosan additionally ensures stable adsorption on clay nanoplatelets due to the strong electrostatic interaction between chitosan and clay. This work thus provides a method to facilitate the design of solid-state hybrid nanomaterials relevant for potential applications in bioimaging, sensing and optical purposes.

scholarly journals A Review of Different Aspects of Applying Asphalt and Bituminous Mixes under a Railway Track

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 169
Author(s):  
Kazem Jadidi ◽  
Morteza Esmaeili ◽  
Mehdi Kalantari ◽  
Mehdi Khalili ◽  
Moses Karakouzian
Keyword(s):  
High Speed ◽  
Review Paper ◽  
Railway Track ◽  
High Speed Train ◽  
Slab Track ◽  
Bituminous Mixtures ◽  
Railway Tracks ◽  
Potential Applications ◽  
Heavy Loads ◽  
Design And Construction

Asphalt is a common material that is used extensively for roadways. Furthermore, bituminous mixes have been used in railways, both as asphalt and as mortar. Different agencies and research institutes have investigated and suggested various applications. These studies indicate the benefits of bituminous material under railways, such as improving a substructure’s stiffness and bearing capacity; enhancing its dynamic characteristics and response, especially under high-speed train loads; waterproofing the subgrade; protecting the top layers against fine contamination. These potential applications can improve the overall track structure performance and lead to minimizing settlement under heavy loads. They can also guarantee an appropriate response under high-speed loads, especially in comparison to a rigid slab track. This review paper documents the literature related to the utilization of asphalt and bituminous mixes in railway tracks. This paper presents a critical review of the research in the application of asphalt and bituminous mixes in railway tracks. Additionally, this paper reviews the design and construction recommendations and procedures for asphalt and bituminous mixes in railway tracks as practiced in different countries. This paper also provides case studies of projects where asphalt and bituminous mixes have been utilized in railway tracks. It is anticipated that this review paper will facilitate (1) the exchange of ideas and innovations in the area of the design and construction of railway tracks and (2) the development of unified standards for the design and construction of railway tracks with asphalt and bituminous mixtures.

A Nanoscale Adventure with Silicon: Synthesis, Surface Chemistry, and other Surprises

2015 ◽  
Vol 242 ◽  
pp. 383-390
Author(s):  
Md Hosnay Mobarok ◽  
Tapas K. Purkait ◽  
Jonathan G.C. Veinot
Keyword(s):  
Quantum Dots ◽  
Optical Properties ◽  
Surface Chemistry ◽  
Research Group ◽  
Size Dependent ◽  
Earth Abundant ◽  
Potential Applications ◽  
Si Quantum Dots

The preparation and surface chemistry Si quantum dots (SiQDs) are currently an intense focus of research because of their size dependent optical properties and many potential applications. SiQDs offer several advantages over other quantum dots; Si is earth abundant, non-toxic and biocompatible. This account briefly highlights recent advancements made by our research group related to the synthesis, functionalization, surface dependent optical properties and applications of SiQDs.

Effect of a magnetic field on anE⊗εJahn-Teller system: Berry phase and optical properties

2001 ◽  
Vol 63 (13) ◽  
Author(s):  
G. Bevilacqua ◽  
L. Martinelli ◽  
G. Pastori Parravicini
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Berry Phase

The Light Absorption Properties of Cu2S Nanowire Arrays

2012 ◽  
Vol 528 ◽  
pp. 272-276 ◽  
Author(s):  
Shan Ren ◽  
Li Qiang Li ◽  
Zhu Feng Liu ◽  
Ming Li ◽  
Lan Hong
Keyword(s):  
Optical Properties ◽  
Distribution Density ◽  
Photovoltaic Cell ◽  
Nanowire Arrays ◽  
Band Gaps ◽  
Infrared Light ◽  
Infrared Band ◽  
Absorption Properties ◽  
Potential Applications ◽  
Cu Foil

Cu2S nanowire arrays with different morphologies were prepared by solid-gas reaction between Cu foil and mixture gas of H2S and O2. Their microstructures were observed with XRD, TEM, and the optical properties were measured by DRS, PL and Raman. The results showed that the nanowire were Cu2S single crystal with a thin layer CuxO (x=1, 2) over the surface. The optical properties of the Cu2S nanowire arrays are related to the diameter, length, and distribution density of nanowire arrays. The thinner is the nanowire’s diameter; the bigger is the absorption of the visible light, and the absorbance begun to descend within infrared band. The absorbance of nanowire arrays with bigger diameter to the infrared light was stronger than that with thinner diameter. The photoluminescence spectrum (PL) indicated that band gaps of Cu2S nanowire arrays also changed simultaneously with the nanowire arrays’ structure parameters. The research demonstrated the Cu2S nanowire arrays’ potential applications in the photovoltaic cell and solar-heat harvesting area.

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