检索结果-内蒙古大学图书馆

Conference on current developments in Lens design and optical engineering XII/Advances in Thin Film Coatings VII

作者： Yang, Bo Lu, Kan Zhang, Wei Dai, Fujian Shanghai Univ Sci & Technol Shanghai Key Lab Contemporary Opt Syst Sch Opt Elect & Comp Engn Shanghai 200093 Peoples R China Zhejiang Sunny Opt Co Ltd R&D Dept Yuyao 315400 Zhejiang Peoples R China

ISBN: (纸本)9780819487384

A free-form lens system design is proposed for short distance projection. Free-form surface shape and non-rotational symmetrical structure provide us more freedoms for optimization. The catadioptric structure is also used to reduce the overall length of the whole system. The designed projector lens system consists of two parts. The first part is a rotationally symmetrical lens system which corrects the basic aberrations. The second part contains a free-form lens and a reflector which correct the distortion and other aberrations. We achieve 55inch projected image size at a display screen which is 300mm away from the lens system. The maximum distortion for all fields at all distances is less than 3%.

关键词： optical engine Projection lens Free-form Catadioptric Least-square fitting

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: Introduction

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

引用

current developments in Lens design and optical engineering XII;and Advances in Thin Film Coatings VII

作者： Johnson, R. Barry Mahajan, Virendra N. Thibault, Simon Alabama A and M University United States Aerospace Corporation United States ImmerVision Canada University Laval Canada

This PDF file contains the front matter associated with SPIE Proceedings Volume 8128, including the Title Page, Copyright information, Table of Contents, Introduction, and the Conference Committee listing. © 2011... 详细信息

ISBN: (纸本)9780819487384

关键词： optical engineering

来源：评论

学校读者我要写书评

暂无评论

Effects of Substrate heating and Vacuum Annealing on optical and Electrical Properties of Alumina-Doped ZnO Films Deposited by DC Magnetron Sputtering

Effects of Substrate heating and Vacuum Annealing on Optical...

引用

Conference on current developments in Lens design and optical engineering XII/Advances in Thin Film Coatings VII

作者： Tang, Chien-Jen Wang, Chun-Yuan Jaing, Cheng-Chung Minghsin Univ Sci & Technol Dept Optoelect Syst Engn Hsinchu 304 Taiwan

ISBN: (纸本)9780819487384

Alumina-doped zinc oxide (AZO) films have wide range of applications in optical and optoelectronic devices. AZO films have advantage in high transparency, high stability to hydrogen plasma and low cost to alternative ITO film. AZO film was prepared by direct-current (DC) magnetron sputtering from ceramic ZnO:Al2O3 target. The AZO films were compared in two different conditions. The first is substrate heating process, in which AZO film was deposited by different substrate temperature, room temperature, 150 degrees C and 250 degrees C. The second is vacuum annealing process, in which AZO film with deposited at room temperature have been annealed at 250 degrees C and 450 degrees C in vacuum. The optical properties, electrical properties, grain size and surface structure properties of the films were studied by UV-VIS-NIR spectrophotometer, Hall effect measurement equipment, x-ray diffraction, and scanning electron microscopy. The resistivity, carrier mobility, carrier concentration, and grain size of AZO films were 1.92x10(-3) Omega-cm, 6.38 cm(2)/Vs, 5.08x10(20) #/cm(3), and 31.48 nm respectively, in vacuum annealing of 450 degrees C. The resistivity, carrier mobility, carrier concentration, and grain size of AZO films were 8.72x10(-4) Omega-cm, 6.32 cm(2)/Vs, 1.13x10(21) #/cm(3), and 31.56 nm, respectively, when substrate temperature was at 250 degrees C. Substrate heating process is better than vacuum annealed process for AZO film deposited by DC Magnetron Sputtering.

关键词： Alumina-Doped ZnO films DC magnetron sputtering vacuum annealed substrate heating process optical properties Electrical properties

来源：评论

学校读者我要写书评

暂无评论

Testing and design of a low-cost large scale solar simulator

Testing and design of a low-cost large scale solar simulator

引用

Conference on current developments in Lens design and optical engineering XII/Advances in Thin Film Coatings VII

作者： Meng, Qinglong Wang, Yuan Changan Univ Sch Environm Sci & Engn 12 Yanta Rd Xian 710054 Shaanxi Provinc Peoples R China Xi An Jiao Tong Univ Sch Energy & Power Engn Xian 710049 Shaanxi Provinc Peoples R China

ISBN: (纸本)9780819487384

To simulate solar radiation at the earth's surface, a new economical multiple-lamp solar simulator was designed. The solar simulator is comprised of 188 reflector sunlight dysprosium lamps whose light spectrum is very similar to air mass 1.5 (AM1.5) solar spectrum terrestrial standards. Lamps are configured in a hexagonal pattern with 15 columns of 12 or 13 lamps at a lamp-to-lamp spacing and column-to-column spacing of 295mm. Without altering the radiation spectral distribution, the average irradiance on target irradiated area can be adjusted over a wide range between 150 and 1100W/m(2) by means of the variation of lamps number or/and lamp-to-irradiated area distance. At the height of 2.0m the solar simulator provides 2mx1.5m irradiated area with over 1000 W/m(2). Measurement of irradiance indicates that the multiple-lamp simulator conforms to Class B of ASTM (American Society for Testing and Materials) Standard (ASTM E927-2005) in regard to spectrum match, irradiance uniformity and stability. To enlarge the effective irradiated area, two large mirror-like stainless steel plates was mounted on both of the long sides of the solar simulator. The radiation characteristics of simulator are improved and the optimized effectively irradiation surface is expanded up to 81.6%.

关键词： solar simulator irradiance nonuniformity temporal instability

来源：评论

学校读者我要写书评

暂无评论

Adaptive optics on Petawatt lasers;current performance of the Texas Petawatt Laser

Adaptive optics on Petawatt lasers;current performance of th...

引用

Conference on Laser Resonators and Beam Control XIII

作者： Martinez, Mikael Gaul, Erhard Borger, Teddy Aymond, Frances Hammond, Douglas Ringuette, Marty Escamilla, Ramiro Ditmire, Todd Caird, John Erlandson, Al Iovanovic, Igor Ebbers, Chris Molander, Bill Univ Texas Austin 2511 Speedway C1510 Austin Austin TX 78712 USA Lawrence Livermore Natl Lab Livermore CA 94550 USA

ISBN: (纸本)9780819484505

In this paper, we report on current developments aimed at improving the focusability of the Texas Petawatt Laser. Two major campaigns have been commissioned that address the issue of focusability. First, we implemented a closed loop, 32 actuator bi-moprh deformable mirror (DFM) to compensate for aberrations in the optical train and second, a color corrector lens assembly was installed that compensates for chromatic errors accumulated in broadband (>15 nm), large aperture (> 20 cm) laser systems. We will present in detail, pre and post correction results with the DFM and describe challenges faced when one activates a single shot, high energy closed loop system. Secondly, we will provide modeling and experimental results of our color correction system. This is a novel approach to a problem only seen in high energy, broadband, large aperture laser pulses. By using color correction optics we have demonstrated a 6X increase in focal intensity. With the installation of the DFM, the rms wavefront error in the system was reduced from 2.4 waves to. 131 waves, further increasing intensities seen at focus by 1 order of magnitude.

关键词： Wavefronts design for manufacturing Diagnostics Laser systems engineering Amplifiers Pulsed laser operation Adaptive optics Crystals Mirrors Wavefront sensors

来源：评论

学校读者我要写书评

暂无评论

current developments in Lens design and optical engineering X

Current Developments in Lens Design and Optical Engineering ...

引用

current developments in Lens design and optical engineering X

ISBN: (纸本)9780819477187

The proceedings contain 22 papers. The topics discussed include: optical design dependence on technology development;practical design considerations for modern photographic optics;display systems and registration methods for mixed reality applications;efficient design process for the evaluation and control of flare in opto-mechanical systems;finding order in the design landscape of simple optical systems;design and optimization of a collimating optical system for high divergence LED light sources;point symmetric design approach to a wide-field wide-wavelength cat's eye retro-reflector anastigmat;fast catadioptric optics with large field of view;thinking outside the barrel: what really matters in modern photographic lens design;calculation of optical forces on a dielectric bead in a geometrically aberrated trap;and relationships between lens performance and different sensor sizes in professional photographic still SLR cameras.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Stability region adaptation using transmission power control for transport capacity optimization in IEEE 802.16 wireless mesh networks

引用

COMPUTER NETWORKS 2011年第16期55卷 3694-3704页

作者： Vejarano, G. Wang, D. McNair, J. Wireless and Mobile Systems Laboratory Department of Electrical and Computer Engineering University of Florida United States

Transmission power control in multihop wireless networks is a challenging problem due to the effects that different node transmission powers have across the layers of the protocol stack. In this paper, we study the problem of transmission power control in IEEE 802.16 mesh networks with distributed scheduling. We consider the effects of transmission power control on the link-scheduling performance when a set of end-to-end flows established in the network are given. The problem is approached by means of the stability region of the link-scheduling policy. Specifically, the stability region is adapted using transmission-power control to the paths of the flows. This adaptation enables the flows to support higher levels of data traffic under lower levels of end-to-end delay. To the best of our knowledge, the approach of stability-region-based transmission power control has not been studied before. We propose a heuristic transmission-power-control algorithm for solving the problem of adapting the stability region to the flows. It is shown, by means of simulation, that the algorithm outperforms the transmission power control based on spatial reuse, which is a widely used approach. Also, it is shown that the solution of the algorithm has performance close to the optimal solution for moderate-sized networks, i.e., networks with no more than 25 nodes and 25 flows. (C) 2011 Elsevier B.V. All rights reserved.

关键词： Power control Transport capacity Throughput maximization Stability region Wimax

来源：评论

学校读者我要写书评

暂无评论

Deep UV LEDs

Deep UV LEDs

引用

International Symposium Semiconductor Device Research (ISDRS)

作者： Remis Gaska Sensor Electronic Technology Inc. USA

Summary form only given. III-Nitride semiconductor-based Deep UV (DUV) LEDs are emerging as an enabling technology for diverse military, homeland security, industrial and commercial markets and space exploration. current technology allows to fabricate AlGaN-based DUV LEDs with wall-plug efficiency (WPE) between 1-2%, which is substantially lower that WPE for visible and near UV LEDs. Significant R&D efforts are under way, including DARPA's “Compact Mid-Ultraviolet Technology” (CMUVT) program, to improve materials quality, device fabrication and light extraction to increase WPE of DUV LEDs by more than order of magnitude. We will present an overview of our latest developments in the development of DUV LED technology with the main focus on novel device designs to increase quantum efficiency and improve UV light extraction and reliability of devices emitting in the range of 230 nm 340 nm. Novel QW design has been implemented to suppress polarization effects and phonon engineering approach to increase electron trapping in the active layer of the devices. Very narrow (; 0.4 eV) quantum wells were used to suppress Stark effect and increase radiative recombination. Active region of DUV LEDs was embedded inside a deep potential well (larger than the energy of optical phonon) to increase electron-LO phonon scattering and accelerate cooling of hot injected electrons. This allowed us to increase electron capture into the active region without using conventional electron "blocking layer" commonly used in visible LEDs We developed and incorporated UV-transparent p-type cladding layers to reduce optical losses due to strong absorption in the top p-AlGaN cladding layer and p+-AlGaN or p+-GaN contact layers. Combination with new type of ohmic contact reflecting in DUV spectral range allowed us to significantly improve light extraction and increase output power of DUV LEDs by 2 times in the range of 275 nm - 300 nm and 2.5 times in the range from 310 nm to 340 nm. Improved quality o

关键词： Light emitting diodes Phonons Semiconductor device reliability optical reflection optical device fabrication

来源：评论

学校读者我要写书评

暂无评论

optical design of the JWST Fine Guider Sensor

Optical Design of the JWST Fine Guider Sensor

引用

Conference on current developments in Lens design and optical engineering XI - and Advances in Thin Film Coatings VI

作者： Zheng, Sheng Hai Evans, Clinton COMDEV Int Ltd Ottawa ON K2K 3J1 Canada

ISBN: (纸本)9780819482822

The Fine Guidance Sensor (FGS) is part of the science instrumentation for the James Webb Space Telescope (JWST). The FGS is required to operate at 37 K and provide the data needed to facilitate fine pointing and attitude stabilization necessary to meet the requirements of the mission's science and engineering operations. We describe here the selection of the proper optical design form to meet requirements and its relative merits. The FGS has progressed with the successful completion of several key design reviews. The optical design of the current stage will be discussed here in detail.

关键词： Fine guidance sensor FGS James Webb space telescope JWST

来源：评论

学校读者我要写书评

暂无评论

design and Implementation of Recording and Readout System for Micro-holographic optical Data Storage

Design and Implementation of Recording and Readout System fo...

引用

Conference on current developments in Lens design and optical engineering XI - and Advances in Thin Film Coatings VI

作者： Takashima, Yuzuru Hesselink, Lambertus Stanford Univ Dept Elect Engn Stanford CA 94305 USA

A lens design having constant working distance while having variable recording depth for micro holographic data storage system has been proposed. Variation of focal length is suppressed for the entire depth within 1% ... 详细信息

ISBN: (纸本)9780819482822

关键词： Holographic Storage Aberrations Lens design

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：