检索结果-内蒙古大学图书馆

Conference on current developments in Lens design and optical engineering XVIII

作者： Leber, I. Niesel, T. Werner, C. Yu, L. Flugge, J. Dietzel, A. TU Braunschweig Inst Mikrotech Alte Salzdahlumer Str 203 D-38124 Braunschweig Germany Phys Tech Bundesanstalt D-38116 Braunschweig Germany Harbin Inst Technol Ultraprecis Opt & Elect Instrument Engn Ctr Harbin 150001 Heilongjiang Peoples R China

ISBN: (纸本)9781510612082;9781510612075

For realization of a miniaturized optical gyroscope the precise assembly of optical micro components is crucial. To detect the rotation rate the laser beam must circulate many times and not leave the resonator due to small misalignments. The assembly of a passive free space triangular ring resonator in which the light can circulate by reflections at three mirrors is investigated. The beam path encloses an area of about 100 mm(2). The resonator shall be activated by an external light source at 1550 nm, a wavelength at which silicon is translucent and allowing to couple light into the resonator through the silicon mirrors. To utilize an inherent mirror alignment two of the mirrors are fabricated with a micro manufacturing process within the same crystal by wet etching resulting in very perfect {111} facets. The etching solution was optimized with respect to process time and smoothness of the mirror surfaces. To further increase the reflectivity of the mirrors different kinds of coatings are tested. With these two perfectly positioned mirrors the assembly challenge reduces to 3DOF alignment of a third {100} mirror for which a well-designed adjustable spacer is developed. In first tests resonance in a linear cavity test setup is demonstrated already.

关键词： silicon micro mirror optical resonator optical gyroscope optical alignment

来源：评论

学校读者我要写书评

暂无评论

optical modeling of bullet-shaped LED for use in self-luminous traffic signs 18

Optical modeling of bullet-shaped LED for use in self-lumino...

引用

Conference on current developments in Lens design and optical engineering XVIII

作者： Lee, Ted L. Chen, Yi-Chun Tsai, Ming-Siou Sun, Ching-Cherng Natl Cent Univ Dept Opt & Photon 300 Zhongda Rd Taoyuan 32001 Taiwan

ISBN: (纸本)9781510612082;9781510612075

Bullet-shaped LEDs are commonly used in self-luminous traffic signs as LED-dotted matrices due to their low cost, simplicity, robustness, and ease of installation. We proposed a simple low-cost method that creates a model suitable for the high manufacturing tolerance found in bullet-shaped LEDs. The method starts from measuring multiple one-dimensional angular intensity patterns at interested distances from multiple LEDs to form a database, including distances at 10, 15, 20, 25, 35, 50, and 100 mm. Their normalized cross-correlations are then calculated to find the batch that has the most similarity and base our model off that batch. Finally, we validate the model via Monte Carlo simulations in comparison to the original one-dimensional angular intensity patterns in the database. The platform demonstrated to obtain an average of 99% in normalized cross correlation between different batches of the same model LED, and a model of that LED is currently under development.

关键词： LED modeling midfield bullet packaging dome package traffic signs

来源：评论

学校读者我要写书评

暂无评论

design of light guide sleeve on hyperspectral imaging system for skin diagnosis 18

Design of light guide sleeve on hyperspectral imaging system...

引用

Conference on current developments in Lens design and optical engineering XVIII

作者： Yan, Yung-Jhe Chang, Chao-Hsin Huang, Ting-Wei Chiang, Hou-Chi Wu Jeng-Fu Mang Ou-Yang Natl Chiao Tung Univ Inst Elect Control Engn Hsinchu Taiwan Natl Chiao Tung Univ Inst Biomed Engn Hsinchu Taiwan Natl Chiao Tung Univ Dept Elect & Comp Engn Hsinchu Taiwan Natl Chung Shan Inst Sci & Technol Taoyuan Taiwan

ISBN: (纸本)9781510612082;9781510612075

A hyperspectral imaging system is proposed for early study of skin diagnosis. A stable and high hyperspectral image quality is important for analysis. Therefore, a light guide sleeve (LGS) was designed for the embedded on a hyperspectral imaging system. It provides a uniform light source on the object plane with the determined distance. Furthermore, it can shield the ambient light from entering the system and increasing noise. For the purpose of producing a uniform light source, the LGS device was designed in the symmetrical double-layered structure. It has light cut structures to adjust distribution of rays between two layers and has the Lambertian surface in the front-end to promote output uniformity. In the simulation of the design, the uniformity of illuminance was about 91.7%. In the measurement of the actual light guide sleeve, the uniformity of illuminance was about 92.5%.

关键词： Light guide Uniform illumination Hyperspectral Image

来源：评论

学校读者我要写书评

暂无评论

Proceedings of SPIE - The International Society for optical engineering

Proceedings of SPIE - The International Society for Optical ...

引用

current developments in Lens design and optical engineering XVIII 2017

ISBN: (纸本)9781510612075

The proceedings contain 35 papers. The topics discussed include: wavefront analysis from its slope data;parametric diffraction efficiency of non-paraxial sinusoidal reflection gratings;camera system MTF: combining optic with detector;diffraction and geometrical optical transfer functions: calculation time comparison;linear decomposition of the optical transfer function for annular pupils;assembly of a micro-optical resonator based on silicon micro mirrors for use in gyroscopes;and fabrication of multi-focal microlens array on curved surface for wideangle camera module.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Contact lens design with slope-constrained Q-type aspheres for myopia correction 18

Contact lens design with slope-constrained Q-type aspheres f...

引用

Conference on current developments in Lens design and optical engineering XVIII

作者： Peng, Wei-Jei Cheng, Yuan-Chieh Hsu, Wei-Yao Yu, Zong-Ru Ho, Cheng-Fang Abou-El-Hossein, Khaled Natl Appl Res Labs Instrument Technol Res Ctr Taiwan 20R&D Rd 6Hsinchu Sci Pk Hsinchu 300 Taiwan Nelson Mandela Metropolitan Univ Precis Engn Lab ZA-6031 Port Elizabeth South Africa

ISBN: (纸本)9781510612082;9781510612075

The design of the rigid contact lens (CL) with slope-constrained Q-type aspheres for myopia correction is presented in this paper. The spherical CL is the most common type for myopia correction, however the spherical aberration (SA) caused from the pupil dilation in dark leads to the degradation of visual acuity which cannot be corrected by spherical surface. The spherical and aspheric CLs are designed respectively based on Liou's schematic eye model, and the criterion is the modulation transfer function (MTF) at the frequency of 100 line pair per mm, which corresponds to the normal vision of one arc-minute. After optimization, the MTF of the aspheric design is superior to that of the spherical design, because the aspheric surface corrects the SA for improving the visual acuity in dark. For avoiding the scratch caused from the contact profilometer, the aspheric surface is designed to match the measurability of the interferometer. The Q-type aspheric surface is employed to constrain the root-mean-square (rms) slope of the departure from a best-fit sphere directly, because the fringe density is limited by the interferometer. The maximum sag departure from a best-fit sphere is also controlled according to the measurability of the aspheric stitching interferometer (ASI). The inflection point is removed during optimization for measurability and appearance. In this study, the aspheric CL is successfully designed with Q-type aspheres for the measurability of the interferometer. It not only corrects the myopia but also eliminates the SA for improving the visual acuity in dark based on the schematic eye model.

关键词： aspheric contact lens Q-type aspheres myopia spherical aberration schematic eye model visual acuity best-fit sphere

来源：评论

学校读者我要写书评

暂无评论

Multi-band filter design with less total film thickness for short-wave infrared 18

Multi-band filter design with less total film thickness for ...

引用

Conference on current developments in Lens design and optical engineering XVIII

作者： Yan, Yung-Jhe Chien, I-Pen Chen, Po-Han Chen, Sheng-Hui Tsai, Yi-Chun Ou-Yang, Mang Natl Chiao Tung Univ Dept Elect & Comp Engn Hsinchu Taiwan Natl Cent Univ Dept Opt & Photon Taoyuan Taiwan

ISBN: (纸本)9781510612082;9781510612075

A multi-band pass filter array was proposed and designed for short wave infrared applications. The central wavelength of the multi-band pass filters are located about 905 nm, 950 nm, 1055 nm and 1550 nm. In the simulation of an optical interference band pass filter, high spectrum performance (high transmittance ratio between the pass band and stop band) relies on (1) the index gap between the selected high/low-index film materials, with a larger gap correlated to higher performance, and (2) sufficient repeated periods of high/low-index thin-film layers. When determining high and low refractive index materials, spectrum performance was improved by increasing repeated periods. Consequently, the total film thickness increases rapidly. In some cases, a thick total film thickness is difficult to process in practice, especially when incorporating photolithography liftoff. Actually the maximal thickness of the photoresist being able to liftoff will bound the total film thickness of the band pass filter. For the application of the short wave infrared with the wavelength range from 900nm to 1700nm, silicone was chosen as a high refractive index material. Different from other dielectric materials used in the visible range, silicone has a higher absorptance in the visible range opposite to higher transmission in the short wave infrared. In other words, designing band pass filters based on silicone as a high refractive index material film could not obtain a better spectrum performance than conventional high index materials like TiO2 or Ta2O5, but also its material cost would reduce about half compared to the total film thickness with the conventional material TiO2. Through the simulation and several experimental trials, the total film thickness below 4 um was practicable and reasonable. The fabrication of the filters was employed a dual electric gun deposition system with ion assisted deposition after the lithography process. Repeating four times of lithography and deposition p

关键词： optical interference filter Photolithography Bandpass filter Short-wave infrared

来源：评论

学校读者我要写书评

暂无评论

optical MEMS for earth observation

Optical MEMS for earth observation

引用

International Conference on Space Optics 2012, ICSO 2012

作者： Liotard, Arnaud Viard, Thierry Noell, Wilfried Zamkotsian, Frédéric Freire, Marco Guldimann, Benedikt Kraft, Stefan Thales Alenia Space Cannes-la-Bocca France EPFL SAMLAB Neuchâtel Switzerland Marseille France ESA – ESTEC Noordwijk Netherlands

ISBN: (纸本)9781510616172

Due to the relatively large number of optical Earth Observation missions at ESA, this area is interesting for new space technology developments. In addition to their compactness, scalability and specific task customization, optical MEMS could generate new functions not available with current technologies and are thus candidates for the design of future space instruments. Most mature components for space applications are the digital mirror arrays, the micro-deformable mirrors, the programmable micro diffraction gratings and tiltable micromirrors. A first selection of market-pull and techno-push concepts is done. In addition, some concepts are coming from outside Earth Observation. Finally two concepts are more deeply analyzed. The first concept is a programmable slit for straylight control for space spectro-imagers. This instrument is a push-broom spectro-imager for which some images cannot be exploited because of bright sources in the field-of-view. The proposed concept consists in replacing the current entrance spectrometer slit by an active row of micro-mirrors. The MEMS will permit to dynamically remove the bright sources and then to obtain a field-of-view with an optically enhanced signal-to-noise ratio. The second concept is a push-broom imager for which the acquired spectrum can be tuned by optical MEMS. This system is composed of two diffractive elements and a digital mirror array. The first diffractive element spreads the spectrum. A micromirror array is set at the location of the spectral focal plane. By putting the micro-mirrors ON or OFF, we can select parts of field-of-view or spectrum. The second diffractive element then recombines the light on a push-broom detector. Dichroics filters, strip filter, band-pass filter could be replaced by a unique instrument. © 2012 ESA and CNES.

关键词： Bandpass filters

来源：评论

学校读者我要写书评

暂无评论

Technological developments for ultra-lightweight, large aperture, deployable mirror for space telescopes

Technological developments for ultra-lightweight, large aper...

引用

International Conference on Space Optics 2010, ICSO 2010

作者： Zuccaro Marchi, Alessandro D'Amato, Francesco Gallieni, Daniele Biasi, Roberto Molina, Marco Duò, Fabrizio Ruder, Nikolaus Salinari, Piero Lisi, Franco Riccardi, Armando Gambicorti, Lisa Simonetti, Francesca Pereira Do Carmo, Joao Pedro N. Largo Enrico Fermi 6 Firenze50125 Italy 23868 Italy Microgate Srl Via Stradivari 4 Bolzano Italy via Gallarate 15 Milano20151 Italy INAF- Arcetri Astrophysics Observatory Largo Enrico Fermi 5 Firenze50125 Italy ESA - ESTEC Keplerlaan 1 Noordwijk2200 AG Netherlands

ISBN: (纸本)9781510616196

The increasing interest on space telescopes for scientific applications leads to implement the manufacturing technology of the most critical element, i.e. the primary mirror: being more suitable a large aperture, it must be lightweight and deployable. The presented topic was originally addressed to a spaceborne DIAL (Differential Absorption LIDAR) mission operating at 935.5 nm for the measurement of water vapour profile in atmosphere, whose results were presented at ICSO 2006 and 2008. Aim of this paper is to present the latest developments on the main issues related to the fabrication of a breadboard, covering two project critical areas identified during the preliminary studies: the design and performances of the long-stroke actuators used to implement the mirror active control and the mirror survivability to launch via Electrostatic Locking (EL) between mirror and backplane. The described work is developed under the ESA/ESTEC contract No. 22321/09/NL/RA. The lightweight mirror is structured as a central sector surrounded by petals, all of them actively controlled to reach the specified shape after initial deployment and then maintained within specs for the entire mission duration. The presented study concerns: a) testing the Carbon Fiber Reinforced Plastic (CFRP) backplane manufacturing and EL techniques, with production of suitable specimens;b) actuator design optimisation;c) design of the deployment mechanism including a high precision latch;d) the fabrication of thin mirrors mock-ups to validate the fabrication procedure for the large shells. The current activity aims to the construction of an optical breadboard capable of demonstrating the achievement of all these coupled critical aspects: optical quality of the thin shell mirror surface, actuators performances and back-plane - EL subsystem functionality. © Copyright SPIE.

关键词： Mirrors

来源：评论

学校读者我要写书评

暂无评论

Space optical instruments design optimisation thanks to CMOS image sensor technology 6

Space optical instruments design optimisation thanks to CMOS...

引用

6th International Conference on Space Optics, ICSO 2006

作者： Saint-Pe, Olivier Tulet, Michel Davancens, Robert Larnaudie, Franck Bréart De Boisanger, Michel Magnan, Pierre Martin-Gonthier, Philippe Corbière, Franck Estribeau, Magali EADS Astrium 31 Avenue des Cosmonautes Toulouse Cédex 431402 France SUPAERO-CIMI 10 Avenue Edouard Belin Toulouse Cédex31055 France

ISBN: (纸本)9781510616233

Today, both CCD and CMOS sensors can be envisaged for nearly all visible sensors and instruments designed for space needs. Indeed, detectors built with both technologies allow excellent electro-optics (EO) performances to be reached, the selection of the most adequate device being driven by their functional and technological features and limits. The first part of the paper shortly recalls how far CMOS Image Sensors (CIS) EO performances have been improved these last years. The second part reviews the advantages of CMOS technology for space applications, illustrated by examples of CIS developments performed by EADS Astrium and Supaéro/CIMI for current and short term coming space programs. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

关键词： Space applications

来源：评论

学校读者我要写书评

暂无评论

Nature of Catalytically Active Sites in the Supported WO₃/ZrO₂ Solid Acid System: A current Perspective

引用

ACS CATALYSIS 2017年第3期7卷 2181-2198页

作者： Zhou, Wu Soultanidis, Nikolaos Xu, Hui Wong, Michael S. Neurock, Matthew Kiely, Christopher J. Wachs, Israel E. Univ Chinese Acad Sci CAS Key Lab Vacuum Sci Sch Phys Sci Beijing 100049 Peoples R China Lehigh Univ Dept Mat Sci & Engn Bethlehem PA 18015 USA Rice Univ Dept Chem & Biomol Engn Houston TX 77005 USA Univ Virginia Dept Chem Engn Charlottesville VA 22904 USA Lehigh Univ Dept Chem & Biomol Engn Bethlehem PA 18015 USA ExxonMobil Chem Co Global Proc Res 4500 Bayway Dr Baytown TX 77575 USA Univ Minnesota Dept Chem Engn & Mat Sci Minneapolis MN 55455 USA

Tungstated zirconia (WO3/ZrO2) is one of the most well studied solid acid catalyst systems and continues to attract the attention of both academia and industry. Understanding and controlling the properties of WO3/ZrO2 catalysts has been a topic of considerable interest over almost the past three decades, with a particular focus on discovering the relationship between catalytic activity and the molecular structure of the surface acid site. Amorphous tungsten oxide (WOx) species on ZrO2 surfaces were previously proposed to be very active for different acidic reactions such as alcohol dehydration and alkane isomerization. Recent developments in electron optical characterization and in situ spectroscopy techniques have allowed researchers to isolate the size, structure, and composition of the most active catalytic species, which are shown to be three-dimensional distorted Zr-WOx clusters (0.8-1.0 nm). Complementary theoretical calculations of the Bronsted acidity of these Zr-WOx clusters have confirmed that they possess the lowest deprotonation energy values. This new insight provides a foundation for the future characterization and theory of acidic supported metal oxide catalytic materials that will, hopefully, lead to the design of more active and selective catalysts. This perspective presents an up-to-date, comprehensive summary of the leading models of W03/ ZrO2 solid acid catalysts.

关键词： solid acid catalyst tungsten oxide zirconium oxide mixed W-Zr oxide clusters spectroscopy electron microscopy theory

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：