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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Geometric modeling and interference detection and prismatic bodies

Ku, Tai-Son. January 1983 (has links)
Thesis (M.S.)--University of Wisconsin--Madison, 1983. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 77-81).
2

Hyperspectral prism-grating-prism imaging spectrograph /

Aikio, Mauri. January 2001 (has links) (PDF)
Thesis (doctoral)--University of Oulu, 2001. / Includes bibliographical references. Also available on the World Wide Web.
3

Analysis and design of modified Wollaston prisms

Montarou, Carole C. 12 1900 (has links)
No description available.
4

Applications of the covering property axiom

Millán Millán, Andrés. January 1900 (has links)
Thesis (Ph. D.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains vi, 72 p. Includes abstract. Includes bibliographical references (p. 69-72).
5

Nonlinear prism coupling in an organic waveguide

Keilbach, Kevin Anthony, 1963- January 1988 (has links)
Computer modeling of prism coupling of pulsed laser irradiation at a wavelength of 1064 nm into an organic polymer waveguide with Kerr Law nonlinearities showed that the prism coupling technique was inherent problems that make it difficult to accurately determine the magnitude of the refractive index change. Uncertainty in knowledge of the gap spacing under the prism leads to errors in any estimates of these nonlinear refractive index changes. Results from prism coupling experiments conducted on a polymer waveguide with a pulsed laser are inconclusive.
6

SOME DESIGN CONSIDERATIONS FOR PRISMATIC ANAMORPHS

Swindell, W. 30 September 1970 (has links)
QC 351 A7 no. 59 / The optical properties of two prisms combined as a single anamorphic element are discussed. There is a family of solutions for which the angular magnification versus field angle is U-shaped. Thus there are regions for which the angular magnification is almost constant. The distortions associated with these regions are explored. It is shown how distortion can be effectively eliminated over a restricted field by cascading a negative and a positive anamorphic element.
7

Infrared Hyperspectral Imaging Stokes Polarimeter

Jones, Julia Craven January 2011 (has links)
This work presents the design, development, and testing of a field portable imaging spectropolarimeter that operates over the short-wavelength and middle-wavelength portion of the infrared spectrum. The sensor includes a pair of sapphire Wollaston prisms and several high order retarders to produce the first infrared implementation of an imaging Fourier transform spectropolarimeter, providing for the measurement of the complete spectropolarimetric datacube over the passband. The Wollaston prisms serve as a birefringent interferometer with reduced sensitivity to vibration when compared to an unequal path interferometer, such as a Michelson. Polarimetric data are acquired through the use of channeled spectropolarimetry to modulate the spectrum with the Stokes parameter information. The collected interferogram is Fourier filtered and reconstructed to recover the spatially and spectrally varying Stokes vector data across the image.The intent of this dissertation is to provide the reader with a detailed understanding of the steps involved in the development of this infrared hyperspectral imaging polarimeter (IHIP) instrument. First, Chapter 1 provides an overview of the fundamental concepts relevant to this research. These include imaging spectrometers, polarimeters, and spectropolarimeters. A detailed discussion of channeled spectropolarimetry, including a historical study of previous implementations, is also presented. Next a few of the design alternatives that are possible for this work are outlined and discussed in Chapter 2. The configuration that was selected for the IHIP is then presented in detail, including the optical layout, design, and operation. Chapter 3 then presents an artifact reduction technique (ART) that was developed to improve the IHIP's spectropolarimetric reconstructions by reducing errors associated with non-band-limited spectral features. ART is experimentally verified in the infrared using a commercial Fourier transform spectrometer in combination with Yttrium Vanadate as well as Cadmium Sulfide retarders.The remainder of this dissertation then details the testing and analysis of the IHIP instrument. Implementation of ART with the IHIP as well as the employed calibration techniques are described in Chapter 4. Complete calibration of the IHIP includes three distinct processes to provide radiometric, spectral, and polarimetric calibration. With the instrument assembled and calibrated, results and error analyses are presented in Chapter 5. Spectropolarimetric results are obtained in the laboratory as well as outdoors to test the IHIP's real world functionality. The performance of the instrument is also assessed, including experimental measurement of signal-to-noise ratio (SNR), and an analysis of the potential sources of systematic error (such as retarder misalignment and finite polarizer extinction ratio). Chapter 6 presents the design and experimental results for a variable Wollaston prism that can be added to the IHIP to vary the fringe contrast across the field of view. Finally, Chapter 7 includes brief closing remarks summarizing this work and a few observations which may be useful for future infrared imaging Fourier transform channeled spectropolarimeter instruments.
8

Computational design and prototype development of optical prism for augmented reality projection.

January 2012 (has links)
虛擬現實(VR)為用家提供了一個結合了人工場境和現實世界的練習環境。隨著在醫療,軍事和娛樂行業日益增長的需求,虛擬現實化的設備將會越來越受歡迎。頭戴式顯示器(HMD)是一種利用自由曲面的光學棱鏡,以投射由微型顯示器顯示的圖像,讓用家能夠在近距離觀看和體驗虛擬環境的產品。 / 頭戴式顯示器由兩個基本部分組成,液晶顯示屏和一個光學元件,以能夠在很短的距離顯示圖像到用家的眼睛。光學自由曲面棱鏡在HMD研究中是一個主要的課題。設計的棱鏡需要運用大多數的光學理論和一些商業光學設計軟件的輔助。在市場,只有有限的光學軟件能深入地協助設計光學元件和系統。同時,成本高昂和不容易使用的光學軟件令到光學設計並不普及的原因。在下面的部分將用光學軟件ZEMAX去驗證每個設計。 / 自由曲面棱鏡的幾何形狀設計是為構建一個頭盔顯示器的關鍵問題。通常情況下,頭盔內自由曲面棱鏡由三面特別設計的非球面表面而組成。源圖像經過三個非球面反映後,可參照圖6,將圖像投射到人類視網膜上而形成圖像。棱鏡上的三個面的互相協調將是一個具有挑戰性的問題。 / 跟據現有的產品和研究分析,研發了一種新風格的棱鏡。在這篇論文中,由射線追踪和光學理論的幫忙,建議了一款凸-平棱鏡作HMD上的光學棱鏡。利用光學設計軟件分析和優化以追求一個可穿戴和低像差的光學棱鏡作目標。光學棱鏡中有兩個面為平面,因此光線能在棱鏡中穩步地轉化,從而,降低光學系統的像差。製作了經優化表面定位的原型,雖然原型是成本低,但它們比半透明的鏡子有一個更好的分辨率。在新設計的一個HMD上,一個廣闊和清晰的圖像將顯示。 / Virtual reality (VR) provides an artificial environment to user for practicing under a synthetic environment which merges the real world with artificial scene. In response to the growing demand in medical, military and entertaining application, devices that can simulate VR will become more and more popular. Head mounted display (HMD) is a kind of wearable products that utilize freeform optical prisms to project images generated by microdisplays, enabling users to situate in virtual environments. / HMD has two basic components, a LCD and an optical element, to display image to naked eye in a short distance. An optical freeform prism will be a main research topic in HMD. To design the prism will require substantial knowledge in optical theory and the aid of some commercial optical design software. In the market, there is limited number of software for in depth optical analysis. Meanwhile, costly and not user-friendly software is a problem of unpopularity of optical design. Zemax has been used for verifying the each design in the below sections. / The design of geometric shape for the freeform prism is crucial for constructing a HMD. Typically, the freeform prisms inside HMD comprise of 3 specially designed aspherical surfaces. The source image is reflected by those three surfaces to form image on human retina. The interplay of three surfaces will is the main challenging problem. With the analysis of existing products and researches, a new-style prism is proposed. In this thesis, with the aid of ray tracing and optical theory, a convex-plano prism is developed. / Analyses of optical design software and optimization are utilized to pursue the goal of wearable and low aberration HMD optical prism. Prototypes with the optimized surfaces alignment are fabricated. With two flat surfaces on the prism, the rays translate steadily in the prism. Hence, the optical system’s aberration is reduced. Although the prototypes are low cost, they have a better resolution than half-transparent mirror. Also a wide and clear image will show on the new style see-through HMD. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Ho, Pui Lam. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 57-59). / Abstracts also in Chinese. / Abstract --- p.i / Abstract (Chinese) 摘要 --- p.iii / Acknowledgement --- p.iv / List of Figure and Table --- p.vii / Paper published --- p.xi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Overview on Near Eye Display (NED) --- p.1 / Chapter 1.2 --- Literature Review on HMD --- p.1 / Chapter 1.3 --- Motivation and Research Objective --- p.7 / Chapter 1.4 --- Thesis Outline --- p.8 / Chapter Chapter 2 --- Fundamental Design Concept --- p.9 / Chapter 2.1 --- Prism --- p.9 / Chapter 2.2 --- Convex Lens --- p.11 / Chapter 2.3 --- Combination of Convex lens and Regular Prism --- p.12 / Chapter Chapter 3 --- Optical Design Analysis by Software Package --- p.16 / Chapter 3.1 --- Surface Alignment --- p.16 / Chapter 3.2 --- Distortion --- p.18 / Chapter 3.3 --- MTF --- p.19 / Chapter 3.4 --- Image Simulation --- p.20 / Chapter 3.5 --- Aberration analysis --- p.21 / Chapter 3.6 --- Aspherical surface --- p.22 / Chapter Chapter 4 --- Design Principle and Procedure --- p.26 / Chapter 4.1 --- Basic Criteria --- p.26 / Chapter 4.2 --- See-throughPurpose --- p.27 / Chapter 4.3 --- Material --- p.28 / Chapter 4.4 --- SurfacesAlignment --- p.29 / Chapter 4.5 --- Compensator --- p.30 / Chapter 4.6 --- Angle Alignment --- p.30 / Chapter Chapter 5 --- System Efficiency --- p.32 / Chapter 5.1 --- System Efficiency --- p.32 / Chapter 5.2 --- System Analysis --- p.35 / Chapter Chapter 6 --- Prototype Fabrication and Testing --- p.38 / Chapter 6.1 --- Display System --- p.38 / Chapter 6.2 --- Monocular Configurations --- p.39 / Chapter 6.3 --- Prototypes Building --- p.40 / Chapter 6.4 --- Advantages --- p.54 / Chapter 6.5 --- Limitation --- p.54 / Chapter Chapter 7 --- Conclusions and Future Work --- p.55 / Chapter 7.1 --- Conclusions --- p.55 / Chapter 7.2 --- Future work --- p.55 / Reference --- p.57 / Appendix --- p.60 / Chapter Appendix 1 --- Background Theory --- p.60 / Chapter A1.1 --- Optical Theory --- p.60 / Chapter A1.2 --- Matrix Method --- p.65 / Chapter A1.3 --- Human Vision --- p.66 / Chapter Appendix 2 --- Simulation of reflection --- p.67 / Chapter Appendix 3 --- Aberration analysis of prisms --- p.70 / Chapter Appendix 4 --- Specification --- p.71
9

Development and Standardization of the NIST Rapid Sulphate Resistance Test

Aleksic, Mila 14 December 2010 (has links)
The NIST miniature paste prism test was developed to assess sulphate resistance of cements faster than the commonly used ASTM C 1012 test. The goal of this research is to address the current limitations regarding the NIST procedure to determine the optimum testing parameters and to establish appropriate expansion limits. A range of variables including details of specimen design, curing regime, water-to-cementitious materials ratio, and prism length were tested on the materials with a wide range of sulphate performance. The findings of the study demonstrate that even though it can yield results in only three months, the NIST test can provide an erroneous differentiation between certain cementitious materials. Reliability and repeatability of the test results can be improved by using longer specimens and longer curing times. The NIST test can be used as a preliminary screening test, but users need to be aware of its limitations.
10

Development and Standardization of the NIST Rapid Sulphate Resistance Test

Aleksic, Mila 14 December 2010 (has links)
The NIST miniature paste prism test was developed to assess sulphate resistance of cements faster than the commonly used ASTM C 1012 test. The goal of this research is to address the current limitations regarding the NIST procedure to determine the optimum testing parameters and to establish appropriate expansion limits. A range of variables including details of specimen design, curing regime, water-to-cementitious materials ratio, and prism length were tested on the materials with a wide range of sulphate performance. The findings of the study demonstrate that even though it can yield results in only three months, the NIST test can provide an erroneous differentiation between certain cementitious materials. Reliability and repeatability of the test results can be improved by using longer specimens and longer curing times. The NIST test can be used as a preliminary screening test, but users need to be aware of its limitations.

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