检索结果-内蒙古大学图书馆

conference on current developments in Lens design and optical engineering XX

作者： Erlikhman, Jacob Krogen, Peter Srinivasan, Prashant Hettel, Will Meinhold, Peter Lubin, Philip Univ Calif Santa Barbara Dept Phys Broida Hall Santa Barbara CA 93106 USA

ISBN: (数字)9781510629028

ISBN: (纸本)9781510629028

Directed energy propulsion for interstellar travel has been proposed as an ideal method for reaching appreciable speeds relative to the speed of light: 0.2c. However, the amount of energy required necessitates a large aperture, on the order of kilometers, while mitigation of atmospheric perturbations requires a discretization of the aperture into many individual laser elements. The use of fiber lasers for these elements obligates mode-matching the fiber to the desired 10 cm aperture for a collimated beam. Various collimation systems were designed and compared. A 3-lens system with one achromat and two aspheric lenses, with two of the lenses used as a Keplerian telescope to achieve a system-shortening effect was analyzed. A similar system made with a plano-convex lens replacing the large-aperture aspheric lens with two additional compensating lenses was compared. A single diffractive optic operating at F/8 was likewise considered. The optical performance of these systems was compared, as was the cost-effectiveness. Scalability to millions of elements was required, so cost-per-system was a crucial consideration factor. Possible manufacturing processes for a diffractive system were investigated, and stamping processes for replication were analyzed to determine the possibility of replication of such an optic reliably, cheaply, and with acceptable results.

关键词： Directed energy optical design diffractive optical elements corrective optical elements laser propulsion

来源：评论

学校读者我要写书评

暂无评论

Freeform Optics design of Primary Lens for Uniform Irradiance Distribution of Concentrator Photovoltaic System 20

Freeform Optics Design of Primary Lens for Uniform Irradianc...

引用

conference on current developments in Lens design and optical engineering XX

作者： Pham Thanh Tuan Duy, N. N. Vu Ngoc Hai Shin, Seoyong Myongji Univ Dept Informat & Commun Engn Gyeonggi Do 17058 South Korea Vietnam Acad Sci & Technol Inst Appl Mat Sci Ho Chi Minh City 70072 Vietnam Phenikaa Univ Elect & Elect Engn Hanoi 1000 Vietnam Duy Tan Univ Fac Nat Sci Danang 550000 Vietnam

ISBN: (数字)9781510629028

ISBN: (纸本)9781510629028

In this paper, a primary lens of concentrator photovoltaic (CPV) system is designed by using freeform optics. The designed lens is constructed based on a basic idea of a combination of Fresnel lens and freeform optics, in which the lens is divided into an array of sub-lenses, which are designed using the conservation of optical path length and the edge ray theorem to get uniform irradiance distribution over the receiver. In this design, every sub-lens is designed to guide the direct sunlight over the receiver with uniform irradiance so that the whole of the primary lens will converge uniformly the direct sunlight over the receiver. The structure of the lens is designed firstly by using Matlab program for every sublens. The Matlab data of the designed lens structure is then used to build the three-dimensional (3D) lens in LightTools (TM) software. The ray tracing technique in LightTools (TM) software is used to find out the optimum structure of the freeform lens. Furthermore, the simulation is performed to estimate the efficiency of the lens as a concentrator of a CPV system by using the light source with the sunlight spectrum. The designed lens can achieve high geometrical concentration ratio and uniform irradiance distribution over the receiver. The simulation results show that the lens can easily reach a high concentration ratio (494 times) with uniform irradiance distribution and good optical efficiency (86%).

关键词： Concentrator photovoltaic (CPV) Primary lens Freeform optics Sub-lenses array Uniform irradiance distribution

来源：评论

学校读者我要写书评

暂无评论

Fundus Camera versus Smartphone Camera Attachment: Image Quality Analysis 20

Fundus Camera versus Smartphone Camera Attachment: Image Qua...

引用

conference on current developments in Lens design and optical engineering XX

作者： Barritt, Nicole Parthasarathy, Mohana Kuppuswamy Faruq, Ibrahim Zelek, John Lakshminarayanan, Vasudevan Univ Waterloo Biomed Engn Waterloo ON Canada Univ Waterloo Sch Optometry & Vis Sci Theoret & Expt Epistemol Lab Waterloo ON Canada Costco Opt Waterloo ON Canada Univ Waterloo Dept Syst Design Engn Waterloo ON Canada Univ Waterloo Dept Phys Waterloo ON Canada Univ Waterloo Dept ECE Waterloo ON Canada Univ Waterloo Dept Syst Design Engn Waterloo ON Canada

ISBN: (数字)9781510629028

ISBN: (纸本)9781510629028

Fundus cameras are the current clinical standard for capturing retinal images, which are used to diagnose a variety of sight-threatening conditions. Traditional fundus cameras are not easily transported, making them unsuitable for field use. In addition, traditional fundus cameras are expensive. Due to this, a variety of technologies have been developed such as the D-EYE Digital Ophthalmoscope (D-EYE Srl, Padova, Italy) which is compatible with various cellphone cameras. This paper reports on the comparison of the image quality of the Nidek RS-330 OCT Retina Scan Duo (Nidek, Tokyo, Japan) and the D-EYE paired with an iPhone 6 (Apple, Cupertino, USA). Twenty-one participants were enrolled in the study of whom 14 underwent nonmydriatic and mydriatic imaging with the D-EYE and the Nidek. Seven participants underwent nonmydriatic imaging with the D-EYE and the Nidek. The images were co-registered and cropped so that the region of interest was equal in both the D-EYE and Nidek images, as the D-EYE had a smaller field of view. Using the Nidek image as the reference, objective full-reference image quality analysis was performed. Metrics such as structural similarity index and peak signal noise ratio were obtained. It was found that the image quality of the D-EYE is limited by the attached iPhone camera, and is lower when compared to the Nidek. Quantification of the differences between the D-EYE and Nidek allows for targeted development of smartphone camera attachments that can help to bridge the current gap in image quality.

关键词： Telemedicine image quality retina fundus images smartphone attachment lenses ophthalmology optometry

来源：评论

学校读者我要写书评

暂无评论

Contact lens design to third order to compensate the spherical aberration of the eye from Zernike polynomials 20

Contact lens design to third order to compensate the spheric...

引用

conference on current developments in Lens design and optical engineering XX

作者： Garcia-Lievanos, O. Teran-Bobadilla, Emiliano Hernandez-Flores, Luis A. Sanchez-Gonzalez, Leticia Inst Politecn Nacl Ctr Interdisciplinario Ciencias Salud Unidad Santo Tomas Dept Optometry Av Maestros S-N Mexico City 11340 DF Mexico Univ Autonoma Sinaloa Dept Optometry Culiacan Rosales 80040 Sininaloa Mexico

ISBN: (数字)9781510629028

ISBN: (纸本)9781510629028

To compensate the spherical aberration of the eye using the conic constant of the first surface of a contact lens for different refractive errors. Refractive errors were simulated by modifying only the first curvature of the cornea. For every refractive error was calculating Zernike polynomials using Optics Software for Layout and Optimization (OSLO) EDU edition with and without contact lens. To calculate the conic constant of the contact lens we use the Seidel sums for thin lenses from the longitudinal spherical aberration as it proposes V. Mahajan. The value of Zernike spherical aberration coefficient for the eye with farsightedness (+ 5.00 D) + spherical contact lens was 0.142691 mu m. The conic constant value to compensate the spherical aberration was -0.222995 and the value of Zernike spherical aberration coefficient of the eye + aspherical contact lens was 0.004354 mu m. The value of Zernike spherical aberration coefficient for the eye with myopia (- 5.00 D) + spherical contact lens was 0.144505 mu m. The conic constant value to compensate the spherical aberration was -0.101424 and the value of Zernike spherical aberration coefficient of the eye + aspherical contact lens was 0.072820 mu m. The proposed method allows us to design contact lenses that compensate for the spherical aberration of the eye from the Zernike polynomials. Although the design of contact lenses is to third order, we obtain a smaller spherical aberration than the chromatic aberration on the axis without use optimization routine.

关键词： Contact lens spherical aberration aberration of the eye and Zernike polynomials

来源：评论

学校读者我要写书评

暂无评论

Comparison of the Efficacy of Three Direct Ophthalmoscopes: A Clinical Study 20

Comparison of the Efficacy of Three Direct Ophthalmoscopes: ...

引用

conference on current developments in Lens design and optical engineering XX

作者： Parthasarathy, Mohana Kuppuswamy Faruq, Ibrahim Arthurs, Eugene Lakshminarayanan, Vasudevan Univ Waterloo Sch Optometry & Vis Sci Theoret & Expt Epistemol Lab Waterloo ON Canada Costco Opt Waterloo ON Canada SPIE Bellingham WA USA Univ Waterloo Dept Phys Waterloo ON Canada Univ Waterloo Dept ECE Waterloo ON Canada Univ Waterloo Dept Syst Design Engn Waterloo ON Canada

ISBN: (数字)9781510629028

ISBN: (纸本)9781510629028

Retinal examination using direct ophthalmoscope is preferred over other techniques for screening purposes because of its portability and high magnification, despite its power sustainability and cost issues. With increasing number of low-cost sustainable devices available in the market, it is important to assess the efficacy of the devices. We compared three devices - Arclight ophthalmoscope, a D-Eye attached to iPhone 6, and conventional ophthalmoscope Heine K180 - in terms of ease of examination, usage, field of view, color rendition, patient comfort, length of examination, and closeness to the eye. Two trained optometrists examined 26 undilated eyes and graded the ease of retinal examination, ease of use and assessed vertical cup:disc ratio (VCDR). Patients reported their comfort level in terms of glare produced by the light source, length of examination and closeness to the eye. The examiners had a good agreement for all assessments. Of 26 eyes, VCDR assessment was not possible in 10/ 26 (38.4%) of the examinations, in (3/26, 11.5%) examinations with Arclight, in 0/26 examinations with D-Eye. Ease of use score was higher for Arclight and D-Eye than Heine. D-Eye had a relatively larger field of view than other 2 devices. Heine ranked first in color rendition. The luminance level of the high-beam setting of Arclight was more than twice that of Heine and D-Eye. Despite that, the patients reported experiencing uncomfortable glare in Heine (14/26, 53.8%), significant glare with Arclight (16/26, 61.5%) and some/no glare with D-Eye. The examination time was shorter when using D-Eye. Overall, D-Eye scored better in most of the evaluation items followed by Arclight.

关键词： Direct Ophthalmoscope Retina cup to disc ratio D-Eye smartphone ophthalmoscope Arclight ophthalmoscope Heine ophthalmoscope solar powered ophthalmoscope

来源：评论

学校读者我要写书评

暂无评论

optical designs of the objectives for special studies in polarizing microscope 19

Optical designs of the objectives for special studies in pol...

引用

19th conference on current developments in Lens design and optical engineering

作者： Frolov, Dmitry N. Vinogradova, Olga A. Frolov, Alexey D. Tabachkov, Alexey G. Project Labor Microscopes Zapovednaya St 51A St Petersburg 194356 Russia

Presents the results of the optical design of lens objectives for polarization light microscopes, including to ensure that the special techniques. Sometimes such methods require the use of objectives similar magnifica... 详细信息

ISBN: (数字)9781510620629

ISBN: (纸本)9781510620629

关键词： Microscopy Lens system design optical design and fabrication Objectives for microscopes Lens objectives system design Objectives for polarizing microscopes Polarizing microscopy

来源：评论

学校读者我要写书评

暂无评论

optical design of CCF PlanApo microobjectives 50 mm observation and super long working distance 19

Optical design of CCF PlanApo microobjectives 50 mm observat...

引用

19th conference on current developments in Lens design and optical engineering

作者： Frolov, Dmitry N. Vinogradova, Olga A. Frolov, Alexey D. Wen, Liyun Jing, Fanhua Project Labor Microscopes Zapovednaya St 51A St Petersburg 194356 Russia Kozo Opt Ltd 19E18 Zhenghong St Nanjing Jiangsu Peoples R China

The main difference is a significant expansion of the linear field, which reaches 50 mm in the image plane. However, in this case, a planapochromatic correction must be achieved for the usual visible spectral range. S... 详细信息

ISBN: (数字)9781510620629

ISBN: (纸本)9781510620629

关键词： Lens system design optical design and fabrication Microscopy Objectives for microscopes

来源：评论

学校读者我要写书评

暂无评论

Integrated multi-objective optimisation of the support structure of heliostats in concentrated solar power plants using a genetic algorithm

引用

IOP conference Series: Materials Science and engineering 2022年第1期1214卷

作者： L Lomazzi F Cadini M Giglio C Cancro G Ciniglio G Graditi A Pontecorvo Politecnico di Milano Department of Mechanical Engineering Via La Masa n.1 Milan Italy Italian National Agency for New Technologies Energy and Sustainable Economic Development ENEA – Research Center Piazza E. Fermi 1 80055 Portici (NA) Italy

The optimisation of the support structure of heliostats in concentrating solar power plants is a fundamental task aimed at attempting to reduce the high levelised cost of energy (LCOE) of current configurations. In this work, an integrated multi-objective optimisation framework is presented, which relies on the combination of a lean and fast structural model with a genetic algorithm to simultaneously minimise both the overall mass of the support structure and the mean angle of rotation of the mirror surface, which directly affects the optical efficiency of the component. A particular feature of the proposed framework is that it represents an integrated solution, i.e., it allows to simultaneously optimise the main components of the heliostat support structure, i.e., the pedestal, the truss and the back support structure, assuming they are off-the-shelf components easily available on the market. The optimisation problem is set up selecting as design variables (i) the number of elements in the back support structure and (ii) the relevant characteristics of all the components considered, i.e., section shape and dimensions, according to the components commercial datasheets. At each iteration of the optimisation process, the structural model is fed with the current design variables values and, according to some computed aerodynamic loads, it allows evaluating the displacement and rotation of the points of interest within the mirror surface. An aerodynamic model present in the literature based on experimental wind tunnel tests is used to estimate the wind forces acting on the heliostat as a function both of the mirror inclination angle with respect to the ground and of the wind direction with respect to the mirror orientation. In this work, the proposed methodology is demonstrated on a realistic case study and the results commented in detail, highlighting possible future developments and the limitations of the framework.

关键词：

来源：评论

学校读者我要写书评

暂无评论

design and Prototyping of a Freeform Light-Guide for Automotive Lighting 19

Design and Prototyping of a Freeform Light-Guide for Automot...

引用

19th conference on current developments in Lens design and optical engineering

作者： Brand, Audrey C. Alisafaee, Hossein Rose Hulman Inst Technol Dept Phys & Opt Engn 5500 Wabash Ave Terre Haute IN 47803 USA

ISBN: (数字)9781510620629

ISBN: (纸本)9781510620629

We have designed a light-guide for lighting applications, including automotive headlamps. The light-guide is designed based on a free-form slab. Our intention has been to optimize the design for creating legal patterns. One of our objectives has been to investigate how the changes in the shape of the freeform light-guide affects the light pattern, and how the light source geometry affects the design. For prototyping purpose, we use a particular polymer that exhibits optical performance close to acrylic (PMMA).

关键词： Automotive Lighting Lighting Light-guide optical design Illumination

来源：评论

学校读者我要写书评

暂无评论

optical design of LED Marine Beacons 19

Optical Design of LED Marine Beacons

引用

19th conference on current developments in Lens design and optical engineering

作者： Lin, Shih-Kang Jen, Yung-Chang Lee, Xuan-Hao Yu, Yeh-Wei Yang, Tsung-Hsun Sun, Ching-Cherng Natl Cent Univ Dept Opt & Photon Chungli 32001 Taiwan Natl Cent Univ Opt Sci Ctr Taoyuan 32001 Taiwan

ISBN: (数字)9781510620629

ISBN: (纸本)9781510620629

Two optical designs for marine beacon based on Direct In-line Package (DIP) LED is proposed and demonstrated. The luminous intensity of the marine beacon using DIP LED can achieve to the IALA recommendation's requirement of 5 nautical miles. The measurement of color coordinates can also fit the IALA recommendation's requirement. By the surface-structured TIR lens, we successfully keep the divergence angle to 68 degrees in the horizontal direction and converge to 8 degrees in the vertical direction.

关键词： DIP LED optical design marine beacons IALA

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：