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

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.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Simon Drieschner ◽  
Fabian Kloiber ◽  
Marc Hennemeyer ◽  
Jan J. Klein ◽  
Manuel W. Thesen

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.


2014 ◽  
Vol 623 ◽  
pp. 108-112
Author(s):  
Yu Qing Wang ◽  
Xi Zhao Li

With the requirements of machining develop towards high precision, high efficiency, intelligentization, combination and greenization, in this paper we develop a NC spherical turning and grinding machine tool with high precision and combination to meet the brisk demand of market for spherical workpieces with large diameter and high precision. According to the enterprises’ practice results ,our machine tool can finish machining of large diameter and high precision sphere quickly, with high quality and low cost, and it has a high practical value.


Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 292 ◽  
Author(s):  
Ziqian He ◽  
Fangwang Gou ◽  
Ran Chen ◽  
Kun Yin ◽  
Tao Zhan ◽  
...  

Continuous, wide field-of-view, high-efficiency, and fast-response beam steering devices are desirable in a plethora of applications. Liquid crystals (LCs)—soft, bi-refringent, and self-assembled materials which respond to various external stimuli—are especially promising for fulfilling these demands. In this paper, we review recent advances in LC beam steering devices. We first describe the general operation principles of LC beam steering techniques. Next, we delve into different kinds of beam steering devices, compare their pros and cons, and propose a new LC-cladding waveguide beam steerer using resistive electrodes and present our simulation results. Finally, two future development challenges are addressed: Fast response time for mid-wave infrared (MWIR) beam steering, and device hybridization for large-angle, high-efficiency, and continuous beam steering. To achieve fast response times for MWIR beam steering using a transmission-type optical phased array, we develop a low-loss polymer-network liquid crystal and characterize its electro-optical properties.


Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 107
Author(s):  
Tao Zhan ◽  
En-Lin Hsiang ◽  
Kun Li ◽  
Shin-Tson Wu

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.


MRS Advances ◽  
2016 ◽  
Vol 1 (43) ◽  
pp. 2947-2952
Author(s):  
L. Chen ◽  
Z.-H. Lu ◽  
T.-M. Lu ◽  
I. Bhat ◽  
S.B. Zhang ◽  
...  

ABSTRACTEpitaxial Ge films are useful as a substrate for high-efficiency solar cell applications. It is possible to grow epitaxial Ge films on low cost, cube textured Ni(001) sheets using CaF2(001) as a buffer layer. Transmission electron microscopy (TEM) analysis indicates that the CaF2(001) lattice has a 45o in-plane rotation relative to the Ni(001) lattice. The in-plane epitaxy relationships are CaF2[110]//Ni[100] and CaF2[$\bar 1$10]//Ni[010]. Energy dispersive spectroscopy (EDS) shows a sharp interface between Ge/CaF2 as well as between CaF2/Ni. Electron backscatter diffraction (EBSD) shows that the Ge(001) film has a large grain size (∼50 μm) with small angle grain boundaries (< 8o). The epitaxial Ge thin film has the potential to be used as a substrate to grow high quality III-V and II-VI semiconductors for optoelectronic applications.


2018 ◽  
Vol 51 (38) ◽  
pp. 385103 ◽  
Author(s):  
Minghuan Liu ◽  
Zhihui Diao ◽  
Li Xuan ◽  
Zenghui Peng ◽  
Lishuang Yao ◽  
...  

2014 ◽  
Vol 41 (2) ◽  
pp. 0202002
Author(s):  
师宇斌 Shi Yubin ◽  
马浩统 Ma Haotong ◽  
马阎星 Ma Yanxing ◽  
吕洋 Lü Yang ◽  
司磊 Si Lei

2018 ◽  
Vol 176 ◽  
pp. 01011
Author(s):  
YE Xin ◽  
JI Qian

The shared economy has been developing rapidly with low cost, low consumption and high environmental efficiency features under the background of internet waves. The shared economy model has emerged in housing, catering, and travel. As people look forward to high quality of life and their social interaction need, the shared kitchen platform arises at the right moment. This paper takes the shared kitchen as an example, focusing on the patients and their caregivers, the existing shared kitchens and its service platform as well as the space system design and human-computer interaction of the shared kitchen have been investigated and analysized. Taking the "high efficiency, the intelligence and the humanization" as the design principles, we are committed to exploring new directions for modular kitchen design under the background of shared economy.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Hoda Akbari ◽  
Izabela Naydenova ◽  
Lina Persechini ◽  
Sean M. Garner ◽  
Pat Cimo ◽  
...  

A holographic device characterised by a large angular range of operation is under development. The aim of this study is to increase the angular working range of the diffractive lens by stacking three layers of high efficiency optical elements on top of each other so that light is collected (and focussed) from a broader range of angles. The angular range of each individual lens element is important, and work has already been done in an acrylamide-based photosensitive polymer to broaden the angular range of individual elements using holographic recording at a low spatial frequency. This paper reports new results on the angular selectivity of stacked diffractive lenses. A working range of 12° is achieved. The diffractive focussing elements were recorded holographically with a central spatial frequency of 300 l/mm using exposure energy of 60 mJ/cm2at a range of recording angles. At this spatial frequency with layers of thickness 50 ± 5 µm, a diffraction efficiency of 80% and 50% was achieved in the single lens element and combined device, respectively. The optical recording process and the properties of the multilayer structure are described and discussed. Holographic recording of a single lens element is also successfully demonstrated on a flexible glass substrate (Corning(R) Willow(R) Glass) for the first time.


2013 ◽  
Vol 756-759 ◽  
pp. 574-578 ◽  
Author(s):  
Xue Zhe Li ◽  
Xiao Hui Feng

The gas sealing performance of electronic sphygmomanometer is an important index of its quality control. At present, the gas leak detection of sphygmomanometer is mainly by manual, which has disadvantages of low efficiency and precision, huge impact of human factors and so on. An automatic and high precision gas sealing performance inspection module is proposed in the paper, which solves the problems of pressure calibration and gas leak detection of sphygmomanometer products. The paper also introduces the principle and implementation of system project. The module is designed by STC12C5A single-chip, KPM DC air pump and the pressure sensor of E8CC, which has advantages of high precision, high efficiency, low cost, and flexible operation etc.


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