scholarly journals High efficiency, low cost holographic optical elements for ultracold atom trapping

2017 ◽  
Vol 25 (1) ◽  
pp. 296 ◽  
Author(s):  
Sebastien Tempone-Wiltshire ◽  
Shaun Johnstone ◽  
Kristian Helmerson
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Ultracold Atom ◽  
Atom Trapping ◽  
Optical Elements ◽  
Holographic Optical Elements

High Efficiency Holographic Optical Elements For All-Optical Digital Computing

1989 ◽  
Author(s):  
M. R. Taghizadeh ◽  
I. R. Redmond ◽  
B. Robertson ◽  
A. C. Walker ◽  
S. D. Smith
Keyword(s):  
High Efficiency ◽  
Optical Elements ◽  
Holographic Optical Elements ◽  
All Optical

High quality diffractive optical elements (DOEs) using SMILE imprint technique

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Simon Drieschner ◽  
Fabian Kloiber ◽  
Marc Hennemeyer ◽  
Jan J. Klein ◽  
Manuel W. Thesen
Keyword(s):  
Soft Lithography ◽  
High Efficiency ◽  
Low Cost ◽  
Industrial Applications ◽  
Diffractive Optical Elements ◽  
Large Area ◽  
High Quality ◽  
Optical Elements ◽  
Uv Curable ◽  
Aspect Ratios

Abstract Augmented reality (AR) enhancing the existing natural environment by overlaying a virtual world is an emerging and growing market and attracts huge commercial interest into optical devices which can be implemented into head-mounted AR equipment. Diffractive optical elements (DOEs) are considered as the most promising candidate to meet the market’s requirements such as compactness, low-cost, and reliability. Hence, they allow building alternatives to large display headsets for virtual reality (VR) by lightweight glasses. Soft lithography replication offers a pathway to the fabrication of large area DOEs with high aspect ratios, multilevel features, and critical dimensions below the diffractive optical limit down to 50 nm also in the scope of mass manufacturing. In combination with tailored UV-curable photopolymers, the fabrication time can be drastically reduced making it very appealing to industrial applications. Here, we illustrate the key features of high efficiency DOEs and how the SMILE (SUSS MicroTec Imprint Lithography Equipment) technique can be used with advanced imprint photopolymers to obtain high quality binary DOEs meeting the market’s requirements providing a very versatile tool to imprint both nano- and microstructures.

scholarly journals Miniature planar telescopes for efficient, wide-angle, high-precision beam steering

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Ziqian He ◽  
Kun Yin ◽  
Shin-Tson Wu
Keyword(s):  
Liquid Crystal ◽  
Optical Tweezers ◽  
High Precision ◽  
High Efficiency ◽  
Low Cost ◽  
Beam Steering ◽  
Large Angle ◽  
High Quality ◽  
Optical Elements ◽  
Optical Efficiency

AbstractNon-mechanical beam steerers with lightweight, compact, high-efficiency, high-precision, and/or large-angle are pivotal for light detection and ranging (LiDAR) of autonomous vehicles, eye-tracking for near-eye displays, microscopy, optical tweezers, and high-precision three-dimensional (3D) printing. However, even the most matured optical phased array can only provide quasi-continuous, efficient beam steering within a small angle range. A telescope module with an angle magnification function can be coupled to enlarge the steering range or precision. But obtaining a compact, low-cost, lightweight, high-quality telescope module with conventional optics remains challenging. Patterned liquid crystal-based planar optical elements offer great design freedom for manipulating the phase profile of light in 2D space. Owing to the advantages of high efficiency, thinness, low cost, easy processing, flexibility, and response to environmental stimuli, a plethora of high-quality optical devices have been demonstrated. Here, a miniature planar telescope mediated by liquid crystal polymers is proposed to offer angle magnification independent of incident spatial location. It consists of two cascaded liquid crystal planar optical elements, each performing a predefined mathematical transformation. By this concept, planar optical elements are fabricated using a new exposure method and assembled into planar telescopes with different magnification factors. Within the incident field range, over 84.6% optical efficiency is achieved with small wavefront distortion. Such a miniature planar telescope shows the potential of cascaded liquid crystal planar optical elements for realizing functionalities that cannot be fulfilled by single optical elements, and enables lightweight, low loss, passive optical transmitters for widespread applications.

Fabrication High Aspect Ratio Nanometer Holes on the Alumina Based on Self-Organization Technology

2014 ◽  
Vol 472 ◽  
pp. 725-728
Author(s):  
Yi Gui Li ◽  
Ling Han Li ◽  
Susumu Sugiyama ◽  
Jing Quan Liu
Keyword(s):  
Aspect Ratio ◽  
Wavelength Range ◽  
High Aspect Ratio ◽  
Large Scale ◽  
High Efficiency ◽  
Low Cost ◽  
Optical Parameter ◽  
Self Organization ◽  
Optical Elements ◽  
Guided Mode

In this paper, a nanofabrication technology of alumina self-organization method for deep and self-arranged nanometer holes on high purity aluminum is presented. Deep and self-arranged nanometer holes can be used as antireflection structures, polarizing elements, guided-mode resonance filters and high efficiency diffraction optical elements. The fabrication technology provided an effective method for low-cost, large-scale manufacturing high aspect ratio nanoholes.The deep nanoholes structure is fabricated by two anodizing processes on aluminum. The theoretical calculation of reflectivity for the fabricated deep holes G-solver sofeware while the measurement setup for the reflectivity of the deep nanoholes is self-made optical parameter test system.The results show that the calculated reflectivity of the deep holes is below 8.0% within the visible wavelength range, while the measured reflectivity of the fabricated nanometer holes is under 8.30% within the wavelength range of 400-760nm and it agrees well with the theoretical analysis result.

Holographic Optical Elements: Advantages and Disadvantages for Efficient Lighting, Sun Protection, and Photovoltaic Power Supply of Buildings

2021 ◽  
pp. 10-15
Author(s):  
Alexei K. Solovyov ◽  
Hong-Tham T. Pham
Keyword(s):  
High Efficiency ◽  
Sun Protection ◽  
Hot Water ◽  
Optical Elements ◽  
Advantages And Disadvantages ◽  
Holographic Optical Elements ◽  
Research Organizations ◽  
Energy Environment ◽  
Hot Water Supply

The research of holographic optical elements (HOE) was carried out very intensively in the 1980s and 1990s. They provided great advantages in high-efficiency natural light, while at the same time providing effective sun protection and did not disturb the free view from the windows. The light-directing qualities of these devices made it possible to concentrate direct and scattered solar energy on photovoltaic batteries and solar collectors for hot water supply and solar heating. However, in recent years, research in this area has become less and less frequent without any explanation. The analysis of the research carried out in the framework of one of the latest projects carried out on behalf of the European Commission under the program “Energy, Environment, and Sustainable Development” (EU Contract Number: ENK6-CT‑2000–00327) with the participation of nine research organizations, higher schools, and universities is presented. The role of each of the participants in this interdisciplinary project was to attract experienced researchers in various fields of science and use their knowledge to obtain an objective result.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

Improvement of Ti/RuO2–IrO2 Anode Lifetime and Electrocatalytical Properties by Using an Eco-Friendly Thermal Decomposition Method Using Polyvinyl Alcohol as Solvent

2019 ◽  
Author(s):  
Charlys Bezerra ◽  
Géssica Santos ◽  
Marilia Pupo ◽  
Maria Gomes ◽  
Ronaldo Silva ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Polyvinyl Alcohol ◽  
High Efficiency ◽  
Electrochemical Impedance ◽  
Pechini Method ◽  
Low Cost ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Calcination Temperatures ◽  
Service Lifetime

<p>Electrochemical oxidation processes are promising solutions for wastewater treatment due to their high efficiency, easy control and versatility. Mixed metal oxides (MMO) anodes are particularly attractive due to their low cost and specific catalytic properties. Here, we propose an innovative thermal decomposition methodology using <a>polyvinyl alcohol (PVA)</a> as a solvent to prepare Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes. Comparative anodes were prepared by conventional method employing a polymeric precursor solvent (Pechini method). The calcination temperatures studied were 300, 400 and 500 °C. The physical characterisation of all materials was performed by X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy, while electrochemical characterisation was done by cyclic voltammetry, accelerated service lifetime and electrochemical impedance spectroscopy. Both RuO<sub>2</sub> and IrO<sub>2</sub> have rutile-type structures for all anodes. Rougher and more compact surfaces are formed for the anodes prepared using PVA. Amongst temperatures studied, 300 °C using PVA as solvent is the most suitable one to produce anodes with expressive increase in voltammetric charge (250%) and accelerated service lifetime (4.3 times longer) besides reducing charge-transfer resistance (8 times lower). Moreover, the electrocatalytic activity of the anodes synthesised with PVA toward the Reactive Blue 21 dye removal in chloride medium (100 % in 30 min) is higher than that prepared by Pechini method (60 min). Additionally, the removal total organic carbon point out improved mineralisation potential of PVA anodes. Finally, this study reports a novel methodology using PVA as solvent to synthesise Ti/RuO<sub>2</sub>–IrO<sub>2</sub> anodes with improved properties that can be further extended to synthesise other MMO compositions.</p>

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