DOCSLIB.ORG

Multiplexed Digital Holography Incorporating Speckle Correlation

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Multiplexed Digital Holography Incorporating Speckle Correlation DOCTORAL T H E SIS Department of Engineering Sciences and Mathematics Division of Fluid and Experimental Mechanics Davood Khodadad Multiplexed Digital incorporating Holography Khodadad Multiplexed Speckle Correlation Davood ISSN 1402-1544 Multiplexed Digital Holography ISBN 978-91-7583-517-4 (print) ISBN 978-91-7583-518-1 (pdf) incorporatingMultiplexed SpeckleDigital Holography Correlation Luleå University of Technology 2016 incorporating Speckle Correlation Davood Khodadad Davood Khodadad Experimental Mechanics Multiplexed Digital Holography incorporating Speckle Correlation Davood Khodadad Luleå University of Technology Department of Engineering Sciences and Mathematics Division of Fluid and Experimental Mechanics February 2016 Printed by Luleå University of Technology, Graphic Production 2016 ISSN 1402-1544 ISBN 978-91-7583-517-4 (print) ISBN 978-91-7583-518-1 (pdf) Luleå 2016 www.ltu.se To you who always believe in me, my beloved parents and sisters, words could never explain how I feel about you. i Preface This work has been carried out at the Division of Fluid and Experimental Mechanics, Department of Engineering Sciences and Mathematics at Luleå University of Technology (LTU) in Sweden. The research was performed during the years 2012-2016, under the supervision of Prof. Mikael Sjödahl, LTU, Dr. Emil Hällstig, Fotonic, and Dr. Erik Olsson, LTU. First I would like to thank my supervisors Prof. Mikael Sjödahl, Dr. Emil Hällstig and Dr. Erik Olsson for their valuable support, ideas and encouragement during this work. I would also like to thank Dr. Per Gren, Dr. Henrik Lycksam and Dr. Eynas Amer for all the help in the lab. Secondly, I would like to express my gratitude to Prof. Wolfgang Osten and Dr. Giancarlo Pedrini at the Institute of Applied Optics at University of Stuttgart, for inviting me to Stuttgart and giving me the opportunity to work in one of the most exciting places in optics in the world. Thanks to Alok Kumar Singh for his help in the laboratory and many fruitful discussions. I am also grateful to the rest of the Coherent Measurement Techniques group at the Institute of Applied Optics for making my visit there both a pleasant and an interesting experience. This work has been a part of the HOLOPRO project and has been financially supported by the Swedish Governmental Agency for Innovation Systems, VINNOVA. I would also like to thank the collaboration partners in this project; the research group at the Division of Scientific Computing at LTU especially Dr. Per Bergström for nice cooperation. I am also grateful for the collaboration with Emil Melander from the Department of Physics and Astronomy, Uppsala University. Furthermore I would like to thank my office mates, Ammar Hazim Saber and Yiling Li; also my colleagues at the Division of Fluid and Experimental Mechanics for interesting discussions and everyone else at the department that made my time here so amazingly inspiring and enjoyable. Finally, I give my deepest gratitude to my beloved family for caring and believing in me, even though not always understanding the meaning of what I have been doing for all these years. Davood Khodadad Luleå, Februaty 2016 ii iii Abstract In manufacturing industry there is a high demand for on line quality control to minimize the risk of incorrectly produced objects. Conventional contact measurement methods are usually slow and invasive, meaning that they cannot be used for soft materials and for complex shapes without influencing the controlled parts. In contrast, interferometry and digital holography in combination with computers become faster, more reliable and highly accurate as an alternative non-contact technique for industrial shape evaluation. For example in digital holography, access to the complex wave field and the possibility to numerically reconstruct holograms in different planes introduce a new degree of flexibility to optical metrology. With digital holography high resolution and precise three dimensional (3D) images of the manufactured parts can be generated. This technique can also be used to capture data in a single exposure, which is important when doing measurements in a disturbed environment. The aim of this thesis is devoted to the theoretical and experimental development of shape and deformation measurements. To perform online process control of free-form manufactured objects, the measured shape is compared with the CAD-model to obtain deviations. To do this, a new technique to measure surface gradients and shape based on single-shot multiplexed dual-wavelength digital holography and image correlation of speckle displacements is demonstrated. Based on an analytical relation between phase gradients and speckle displacements it is shown that an object is retrieved uniquely to shape, position and deformation without the unwrapping problems that usually appear in dual-wavelength holography. The method is first demonstrated using continues-wave laser light from two temperature controlled laser diodes operating at 640 nm. Then a specially designed dual core diode pumped fiber laser that produces pulsed light with wavelengths close to 1030 nm is used. In addition, a Nd:YAG laser with the wavelength of 532 nm is used for 3D deformation measurements. One significant problem when using the dual-wavelength single-shot approach is that phase ambiguities are built in to the system that needs to be corrected. An automatic calibration scheme is therefore required. The intrinsic flexibility of digital holography gives a possibility to compensate these aberrations and to remove errors, fully numerically without mechanical movements. In this thesis I present a calibration method which allows multiplexed single- shot online shape evaluation in a disturbed environment. It is shown that phase maps and speckle displacements can be recovered free of chromatic aberrations. This is the first time iv that a multiplexed single-shot dual-wavelength calibration is reported by defining a criteria to make an automatic procedure. Further, Digital Speckle Photography (DSP) is used for the full field measurement of 3D deformations. In order to do 3D deformation measurement, usually multi-cameras and intricate set-up are required. In this thesis I demonstrate the use of only one single camera to record four sets of speckle patterns recorded by illuminating the object from four different directions. In this manner, meanwhile 3D speckle displacement is calculated and used for the measurement of the 3D deformations, wrapping problems are also avoided. Further, the same scale of speckle images of the surface for all four images is guaranteed. Furthermore, a need for calibration of the 3D deformation measurement that occurs in the multi-camera methods, is removed. By the results of the presented work, it is experimentally verified that the multiplexed single- shot dual wavelength digital holography and numerically generated speckle images can be used together with digital speckle correlation to retrieve and evaluate the object shape. Using multidirectional illumination, the 3D deformation measurements can also be obtained. The proposed method is robust to large phase gradients and large movements within the intensity patterns. The advantage of the approach is that, using speckle displacements, shape and deformation measurements can be performed even though the synthetic wavelength is out of the dynamic range of the object deformation and/or height variation. v Thesis This thesis consists of a background of the work and the following papers: Paper A D. Khodadad, E. Hällstig, and M. Sjödahl, "Dual-wavelength digital holographic shape measurement using speckle movements and phase gradients," Optical Engineering, vol. 52, pp. 101912-101912, 2013. Paper B P. Bergström, D. Khodadad, E. Hällstig, and M. Sjödahl, "Dual-wavelength digital holography: single-shot shape evaluation using speckle displacements and regularization," Applied Optics, vol. 53, pp. 123-131, 2014. Paper C D. Khodadad, P. Bergström, E. Hällstig, and M. Sjödahl, "Single Shot Dual- Wavelength Digital Holography: Calibration Based on Speckle Displacements," International Journal of Optomechatronics 8, 326-339 (2014). Paper D D. Khodadad, P. Bergström, E. Hällstig, and M. Sjödahl, "Fast and robust automatic calibration for single-shot dual-wavelength digital holography based on speckle displacements," Applied Optics, vol. 54, pp. 5003-5010 (2015). Paper E D. Khodadad, A. K. Singh, G. Pedrini, W. Osten, and M. Sjödahl, " Full field 3D deformation measurement based on 3D laser speckle displacements," manuscript. Additional papers, related to the thesis but not included: Paper F D. Khodadad, "Phase-derivative-based estimation of digital reference wave from single off-axis digital hologram," Applied Optics, vol. 55(12), 2016. Paper G D. Khodadad, E. Amer, P. Gren, E. Melander, E. Hällstig and M. Sjödahl, " Single-shot dual-polarization holography: measurement of the polarization state of a magnetic sample," Proc. SPIE 9660, SPECKLE 2015: VI vi International Conference on Speckle Metrology, 96601E (August 24, 2015); doi:10.1117/12.2189782; http://dx.doi.org/10.1117/12.2189782 Paper H D. Khodadad, P. Bergström, E. Hällstig, and M. Sjödahl, " Dual-wavelength digital holography: single shot calibration ", Proc. SPIE 9203, Interferometry XVII: Techniques and Analysis, 920305 (August 18, 2014); doi:10.1117/12.2062101; http://dx.doi.org/10.1117/12.2062101 Paper I P. Bergström, D. Khodadad, E. Hällstig, and M. Sjödahl, " Single Shot Shape Evaluation Using Dual-Wavelength Holographic
Load more

Recommended publications
  • Laser Speckle Imaging: a Quantitative Tool for Flow Analysis
    LASER SPECKLE IMAGING: A QUANTITATIVE TOOL FOR FLOW ANALYSIS A Thesis presented to the Faculty of California Polytechnic State University, San Luis Obispo In Partial Fulfillment of the Requirements for the Degree Master of Science in Biomedical Engineering by Taylor Andrew Hinsdale June 2014 © 2014 Taylor Andrew Hinsdale ALL RIGHTS RESERVED ii COMMITTEE MEMBERSHIP TITLE: Laser Speckle Imaging: A Quantitative Tool for Flow Analysis AUTHOR: Taylor Andrew Hinsdale DATE SUBMITTED: June 2104 COMMITTEE CHAIR: Lily Laiho, PhD Associate Professor of Biomedical Engineering COMMITTEE MEMBER: David Clague, PhD Associate Professor of Biomedical Engineering COMMITTEE MEMBER: John Sharpe, PhD Professor of Physics iii ABSTRACT Laser Speckle Imaging: A Quantitative Tool for Flow Analysis Taylor Andrew Hinsdale Laser speckle imaging, often referred to as laser speckle contrast analysis (LASCA), has been sought after as a quasi-real-time, full-field, flow visualization method. It has been proven to be a valid and reliable qualitative method, but there has yet to be any definitive consensus on its ability to be used as a quantitative tool. The biggest impediment to the process of quantifying speckle measurements is the introduction of additional non dynamic speckle patterns from the surroundings. The dynamic speckle pattern under investigation is often obscured by noise caused by background static speckle patterns. One proposed solution to this problem is known as dynamic laser speckle imaging (dLSI). dLSI attempts to isolate the dynamic speckle signal from the previously mentioned background and provide a consistent dynamic measurement. This paper will investigate the use of this method over a range of experimental and simulated conditions.
    [Show full text]
  • Industrial Applications of Speckle Techniques
    TRITA-IIP-02-03 ISSN-1650-1888 Industrial Applications of Speckle Techniques -Measurement of Deformation and Shape Wei An Doctoral Thesis Chair of Industrial Metrology & Optics Department of Production Engineering Stockholm 2002 Royal Institute of Technology Industrial Applications of Speckle Techniques -Measurement of Deformation and Shape Wei An Doctoral Thesis TRITA-IIP-02-03 ISSN-1650-1888 Royal Institute of Technology Department of Production Engineering Chair of Industrial Metrology & Optics 100 44 Stockholm, Sweden 2002 TRITA-IIP-02-03 ISSN-1650-1888 Copyright © Wei An Department of Production Engineering Royal Institute of Technology S-100 44 Stockholm Sweden ABSTRACT Modern industry needs quick and reliable measurement methods for measuring deformation, position, shape, roughness, etc. This thesis is mainly concerned with industrial applications of speckle metrology. Speckle metrology is an optical non-contact whole field technique that provides the means to measure; deformation and displacement, object shape, surface roughness, vibration, and dynamic events, on rough surfaces and with a sensitivity of the order of a light wavelength. In particular, the electronic speckle metrology technique combined with advanced computers, fast frame grabbers, and image processing makes it very suitable for industrial applications. The thesis consists of four main parts. The first part presents the basic principle of speckle metrology. Some formulas and theoretical analysis are reviewed. The procedure of recording electronic speckle patterns is discussed. The phase shifting and the phase unwrapping techniques are also presented in this part. The second part considers some applications of speckle metrology technique. Four types of measurements have been done during this thesis period. They correspond to deformation measurements of solder joints on electronic device boards, 3D shape measurement with light-in-flight electronic speckle pattern interferometry, continuous deformation measurement, and cutting tool monitoring.
    [Show full text]
  • Laser Speckle Photometry – Optical Sensor Systems for Condi- Tion and Process Monitoring
    MATERIALS TESTING FOR JOINING AND ADDITIVE MANUFACTURING APPLICATIONS 213 Laser speckle photometry – Optical sensor systems for condi- tion and process monitoring Lili Chen, Ulana Cikalova, Beatrice Bendjus, Laser speckle photometry (LSP) is an innovative, non-destruc- Andreas Gommlich, Shohag Roy Sudip, tive monitoring technique based on the detection and analy- Carolin Schott, Juliane Steingroewer, Dresden, sis of thermally or mechanically activated speckle dynamics Matthias Belting, Aachen, and in a non-stationary optical field. With the development of Stefan Kleszczynski, Duisburg, Germany speckle theories, it has been found that speckle patterns carry information about surface characteristics. Therefore, LSP offers a great potential for the characterization of mate- rial properties and monitoring of manufacturing processes. In contrast to the speckle interferometry method, LSP is very simple and robust. The sample is illuminated by only one la- ser beam to generate a speckle pattern on the surface. The Article Information signals obtained are directly recorded by a CCD or CMOS Correspondence Address Dr.-Ing. Beatrice Bendjus camera. By appropriate optical solutions for the beam path, Fraunhofer Institute for Ceramic typically, resolutions of less than 10 μm are reached if larger Technologies and Systems IKTS Maria-Reiche-Str. 2 areas are illuminated. LSP is definitely a contactless, quick 01109 Dresden, Germany and quality relevant material characterization and defect de- E-mail: [email protected] tection method, allowing process monitoring in many indus- Keywords trial fields. Examples from online biotechnological monitoring Laser speckle photometry, process-monitoring, defect-monitoring, build-up welding, additive and laser based manufacturing demonstrate further poten- manufacturing, biomass tials of the method for process monitoring and controlling.
    [Show full text]
  • Robustness of Laser Speckles As Unique Traceable Markers of Metal Components
    Article Robustness of Laser Speckles as Unique Traceable Markers of Metal Components Mikael Sjödahl * and Erik Olsson Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-971 87 Luleå, Sweden; [email protected] * Correspondence: [email protected] Abstract: The traceability of manufactured components is growing in importance with the greater use of digital service solutions offered and with an increased digitalization of manufacturing logistics. In this paper, we investigate the use of image-plane laser speckles as a tool to acquire a unique code from the surface of the component and the ability to use this pattern as a secure component-specific digital fingerprint. Intensity correlation is used as a numerical identifier. Metal sheets of different materials and steel pipes are considered. It is found that laser speckles are robust against surface alterations caused by surface compression and scratching and that the correct pattern reappears from a surface contaminated by oil after cleaning. In this investigation, the detectability is close to 100% for all surfaces considered, with zero false positives. The exception is a heavily oxidized surface wiped by a cotton cloth between recordings. It is further found that the main source for lost detectability is caused by misalignment between the registration and detection geometries where a positive match is lost by a change in angle in the order of 60 mrad. Therefore, as long as the registration and detection systems, respectively, use the same optical arrangement, laser speckles have the ability to serve as unique component identifiers without having to add extra markings or a dedicated sensor to the component.
    [Show full text]
  • Customizing Speckle Intensity Statistics
    Research Article Vol. 5, No. 5 / May 2018 / Optica 595 Customizing speckle intensity statistics 1 1 2 1, NICHOLAS BENDER, HASAN YILMAZ, YARON BROMBERG, AND HUI CAO * 1Department of Applied Physics, Yale University, New Haven, Connecticut 06520, USA 2Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel *Corresponding author: [email protected] Received 9 February 2018; revised 6 April 2018; accepted 7 April 2018 (Doc. ID 322894); published 9 May 2018 Speckles commonly satisfy Rayleigh statistics. However, in many applications, non-Rayleigh speckles with customized intensity statistics are desirable. Here, we present a general method for customizing the intensity statistics of speckle patterns on a target plane. By judiciously modulating the phase front of a monochromatic laser beam, we experi- mentally generate speckle patterns with arbitrarily tailored intensity probability density functions. Relative to Rayleigh speckles, our customized speckles exhibit radically different topologies yet maintain the same spatial corre- lation length. The customized speckles are fully developed, ergodic, and stationary–with circular non-Gaussian statistics for the complex field. Propagating away from the target plane, the customized speckles revert back to Rayleigh speckles. This work provides a versatile framework for tailoring speckle patterns with varied applications in microscopy, imaging, and optical manipulation. © 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement OCIS codes: (030.0030) Coherence and statistical optics; (030.6140) Speckle; (030.6600) Statistical optics. https://doi.org/10.1364/OPTICA.5.000595 1. INTRODUCTION the speckle pattern could possess an intensity PDF with a tail Speckle formation is a phenomenon inherent to both classical and decaying either slower or faster than a negative-exponential func- quantum waves.
    [Show full text]
  • Simple and Versatile Heterodyne Whole-Field Interferometer for Phase Optics Characterization D
    Simple and versatile heterodyne whole-field interferometer for phase optics characterization D. M. Silva, E. A. Barbosa, and N. U. Wetter Citation: Rev. Sci. Instrum. 83, 103103 (2012); doi: 10.1063/1.4757396 View online: http://dx.doi.org/10.1063/1.4757396 View Table of Contents: http://rsi.aip.org/resource/1/RSINAK/v83/i10 Published by the American Institute of Physics. Related Articles Continuously tunable optical multidimensional Fourier-transform spectrometer Rev. Sci. Instrum. 84, 023107 (2013) The frequency stabilization method of laser feedback interferometer based on external cavity modulation Rev. Sci. Instrum. 84, 025108 (2013) Efficient end-fire coupling of surface plasmons on flat metal surfaces for improved plasmonic Mach-Zehnder interferometer J. Appl. Phys. 113, 053101 (2013) Automation of an “Aculight” continuous-wave optical parametric oscillator Rev. Sci. Instrum. 84, 013102 (2013) Two-path solid-state interferometry using ultra-subwavelength two-dimensional plasmonic waves Appl. Phys. Lett. 102, 021104 (2013) Additional information on Rev. Sci. Instrum. Journal Homepage: http://rsi.aip.org Journal Information: http://rsi.aip.org/about/about_the_journal Top downloads: http://rsi.aip.org/features/most_downloaded Information for Authors: http://rsi.aip.org/authors Downloaded 14 Mar 2013 to 143.107.255.190. Redistribution subject to AIP license or copyright; see http://rsi.aip.org/about/rights_and_permissions REVIEW OF SCIENTIFIC INSTRUMENTS 83, 103103 (2012) Simple and versatile heterodyne whole-field interferometer for
    [Show full text]
  • Robust Single Shot Structured Light
    Robust Single-Shot Structured Light 3D Scanning Robuste 3D-Vermessung mit strukturierter Beleuchtung in Einzelbildern Der Technischen Fakultät der Universität Erlangen–Nürnberg zur Erlangung des Grades DOKTOR–INGENIEUR vorgelegt von Christoph Schmalz Erlangen — 2011 Als Dissertation genehmigt von der Technischen Fakultät der Universität Erlangen-Nürnberg Tag der Einreichung: 29.08.2011 Tag der Promotion: 05.03.2012 Dekan: Prof. Dr.-Ing. habil. Marion Merklein Berichterstatter: Prof. Dr.-Ing. Joachim Hornegger Prof. Dr.-Ing. Gerd Häusler Abstract In this thesis a new robust approach for Single-Shot Structured Light 3D scanning is developed. As the name implies, this measurement principle requires only one image of an object, illuminated with a suitable pattern, to reconstruct the shape and distance of the object. This technique has several advantages. It can be used to record 3D video with a moving sensor or of a moving scene. Since the required hardware is very simple, the sensor can also be easily miniaturized. Single-Shot Structured Light, thus, has the potential to be the basis of a versatile and inexpensive 3D scanner. One focus of the work is the robustness of the method. Existing approaches are mostly limited to simple scenes, that is, smooth surfaces with neutral color and no external light. In contrast, the proposed method can work with almost any close-range scene and produces reliable range images even for very low-quality input images. An important consideration in this respect is the design of the illumination pattern. We show how suitable color stripe patterns for different applications can be created. A major part of the robustness is also due to the graph-based decoding algorithm for the pattern images.
    [Show full text]
  • Universal Sensitivity of Speckle Intensity Correlations to Wavefront Change in Light Diffusers
    Universal sensitivity of speckle intensity correlations to wavefront change in light diffusers KyungDuk Kim,1 HyeonSeung Yu,1 KyeoReh Lee,1 and YongKeun Park1* 1Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Republic of Korea Here, we present a concept based on the realization that a complex medium can be used as a simple interferometer. Changes in the wavefront of an incident coherent beam can be retrieved by analyzing changes in speckle patterns when the beam passes through a light diffuser. We demonstrate that the spatial intensity correlations of the speckle patterns are independent of the light diffusers, and are solely determined by the phase changes of an incident beam. With numerical simulations using the random matrix theory, and an experimental pressure-driven wavefront- deforming setup using a microfluidic channel, we theoretically and experimentally confirm the universal sensitivity of speckle intensity correlations, which is attributed to the conservation of optical field correlation despite multiple light scattering. This work demonstrates that a complex media is a simple interferometer, and presents opportunities to replace complicated reference-beam-assisted interferometers with a simple and compact scattering layer in various applications in metrology, analytical chemistry, and biomedicine. I. INTRODUCTION Speckle is a granular pattern that appears when highly coherent light is scattered by a random structure [1]. In contrast to efforts to suppress speckle to improve imaging quality [2-5], there have also been approaches to exploit speckle patterns as a means of gathering physical information about a target. This field of research, known as speckle metrology, enables the measurement of various physical quantities such as vibration [6], roughness [7], and velocity [8].
    [Show full text]
  • Application of Electronic Speckle Pattern Interferometry Method for Simultaneous Measurement of Young’S Modulus and the Poisson’S Ratio of Metals †
    Proceedings Application of Electronic Speckle Pattern Interferometry Method for Simultaneous Measurement of Young’s Modulus and the Poisson’s Ratio of Metals † Alexandre Michtchenko *, Juan Benito Pascual Francisco and Omar Barragán Pérez Instituto Politécnico Nacional, Seccion de Estudios de Posgrado e Investigación, ESIME-ZAC, México 07738, Mexico; [email protected] (J.B.P.F.); [email protected] (O.B.P.) * Correspondence: [email protected]; Tel.: +52-5512-9773-26 † Presented at the 18th International Conference on Experimental Mechanics (ICEM18), Brussels, Belgium, 1–5 July 2018. Published: 28 June 2018 Abstract: In this paper, mechanical experiments with a low-cost interferometry set-up are presented. The set-up is suitable for an undergraduate laboratory where optical equipment is absent. The arrangement consists of two planes of illumination, allowing the measurement of the two perpendicular in-plane displacement directions. An axial load was applied to three different metals, and the longitudinal and transversal displacements were measured sequentially. A digital camera was used to acquire the images of the different states of the load of the illuminated area. A personal computer was used to perform the digital subtraction of the images to obtain the fringe correlations, which are needed to calculate the displacements. Finally, Young’s modulus and Poisson’s ratio of the metals were calculated using the displacement data. Keywords: electronic speckle pattern interferometry; Poisson’s ratio; Young’s modulus 1. Introduction Electronic Speckle Pattern Interferometry (ESPI) is a technique for full-field displacement measurement and has been well accepted in experimental mechanics field [1,2]. Sophisticated equipment has been developed for this purpose, and usually employ relative expensive items such as CCD camera, frame grabber, mirror mounts, PZT, etc.
    [Show full text]
  • Speckling in Diffraction Patterns and Optical Images Formed with the Laser
    viii SPECKLING IN DIFFRACTION PATTERNS AND OPTICAL IMAGES FORMED WITH THE LASER H.H. Hopkins H. Tiziani The University, Reading E.T.H., Zurich Abstract Elementary physical considerations are used to show that the waves scattered from an optically rough surface have not only random phases but also random real amplitudes. The same simple physical model serves to establish the main features of speckling in diffraction patterns, namely (i) that the smallest size of detail in any azimuth is determined by the formula O.5A/e, where 0 is the angular diameter of the object in that azimuth, (ii) that the scale of the speckling is predominantly of this order of size, and (iii) that speckling is expected to be of high contrast. This last conclusion is easily derived from the randomness of the real amplitudes of the scattered waves. The result (ii) is obtained by finding the autocorrelation function of the diffracted intensity distribution, following Goldfischer (1965). In the formation of the image of a rough object using coherent light, the entrance pupil is illuminated by a speckled diffraction pattern. This random illumination then appears in the exit pupil, so that the speckling in the image is determined by considering the exit pupil to act as a rough object. The order of size of speckling in the image is thus determined by the formula O. S6 /A, where 6 is now the total convergence angle of the image-forming pencil. 0 0 (1) Physical Considerations : The Envelope of the Diffraction Pattern and the Minimum Size of Speckle We silall consider first the factors wbich determine the form of the envelope of the intensity in the diffraction pattern.
    [Show full text]
  • Holographic and Speckle Methods - A
    EXPERIMENTAL MECHANICS - Holographic and Speckle Methods - A. Albertazzi G. Jr, M. R. Viotti HOLOGRAPHIC AND SPECKLE METHODS A. Albertazzi G. Jr Department of Mechanical Engineering, Universidade Federal de Santa Catarina, Brazil M. R. Viotti Optical Metrology Division, Photonita Ltda, Brazil Keywords: Experimental mechanics, optical metrology, holography, holographic interferometry, digital holography, speckle, speckle correlation, speckle interferometry, DSPI, ESPI. Contents 1. Holographic Methods 1.1. Light Waves 1.1.1. Wave mathematics 1.1.2. Interference 1.1.3. Interference Fringes 1.1.4. Phase Extraction 1.2. Film Holography 1.2.1. Hologram Recording 1.2.2. Hologram Reconstruction 1.3. Holographic Interferometry 1.3.1. Double Exposure Holographic Interferometry 1.3.2. Real Time Holographic Interferometry 1.3.3. Time Average Holographic Interferometry 1.3.4. Interpretation of Interference Fringes 1.3.5. Special Applications 1.4. Digital Holography 1.4.1. Basic Principle 1.4.2. Digital holographic interferometry 2. Speckle Methods 2.1 The speckle effect 2.1.1. Objective speckle 2.1.2. Subjective speckle 2.2 Speckle Photography 2.3. Digital Speckle Interferometry 2.3.1. Basic Principle 2.3.2. Interpretation of Interference Fringes 2.3.3. Special Configurations 2.3.4. Vibration measurement 2.4. Shearography 2.4.1. Basic principle 2.4.2. Formation and Interpretation of Interference Fringes 2.4.3. Applications Glossary ©Encyclopedia of Life Support Systems(EOLSS) EXPERIMENTAL MECHANICS - Holographic and Speckle Methods - A. Albertazzi G. Jr, M. R. Viotti Bibliography Biographical Sketches Summary Two important full filed optical techniques widely used in experimental mechanic applications are presented in this topic: holography and speckle methods.
    [Show full text]
  • Speckle Mechanism in Holographic Optical
    SPECKLE MECHANISM IN HOLOGRAPHIC OPTICAL COHERENCE IMAGING _______________________________________________________________________________ A Dissertation Presented to The Faculty of the Graduate School University of Missouri _____________________________________________________________ In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy _____________________________________________________________ By HAIBO LIN Dr. Ping Yu, Dissertation Supervisor May 2009 The undersigned, appointed by the Dean of the Graduate School, have examined the dissertation entitled: SPECKLE MECHANISM IN HOLOGRAPHIC OPTICAL COHERENCE IMAGING presented by Haibo Lin a candidate for the degree of Doctor of Philosophy and hereby certify that in their opinion, it is worthy of acceptance. ____________________________________ Dr. Ping Yu ____________________________________ Dr. Liqun (Andrew) Gu ____________________________________ Dr. Meera Chandrasekhar ____________________________________ Dr. Suchismita Guha ____________________________________ Dr. H. R. Chandrasekhar To my parents: Aimei He and Zhimin Lin and my wife: Huifang Zhai ACKNOWLEDGEMENTS I have been fortunate to work with professors who have been encouraging and supportive of my endeavors during my Ph.D. study. I would like to specially thank my thesis advisor, Prof. Ping Yu who has been invaluable in his constant support, continuous motivation and inspiration, and in allowing me to work in an environment with the freedom to explore different avenues of research. In giving me the opportunity to attend conferences, he has contributed immeasurably to my personal and professional growth. I would like to thank Prof. Lixin Ma and Dr. Sunder Balasubramanian for their help and support since the beginning of my research. Thanks to Prof. David Nolte, Dr. Kwan Jeong and Yihong Liu from Purdue University for generously providing the quantum well device and training for device fabrication.
    [Show full text]