Michigan Technological University Digital Commons @ Michigan Tech Dissertations, Master's Theses and Master's Reports 2019 Enhancing the Resolution of Imaging Systems by Spatial Spectrum Manipulation Wyatt Adams Michigan Technological University, [email protected] Copyright 2019 Wyatt Adams Recommended Citation Adams, Wyatt, "Enhancing the Resolution of Imaging Systems by Spatial Spectrum Manipulation", Open Access Dissertation, Michigan Technological University, 2019. https://doi.org/10.37099/mtu.dc.etdr/861 Follow this and additional works at: https://digitalcommons.mtu.edu/etdr Part of the Electromagnetics and Photonics Commons ENHANCING THE RESOLUTION OF IMAGING SYSTEMS BY SPATIAL SPECTRUM MANIPULATION By Wyatt Adams A DISSERTATION Submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY In Electrical Engineering MICHIGAN TECHNOLOGICAL UNIVERSITY 2019 © 2019 Wyatt Adams This dissertation has been approved in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY in Electrical Engineering. Department of Electrical and Computer Engineering Dissertation Advisor: Dr. Durdu G¨uney Committee Member: Dr. Paul Bergstrom Committee Member: Dr. Christopher Middlebrook Committee Member: Dr. Miguel Levy Department Chair: Dr. Glen Archer Dedication To my parents for their love, guidance, and wisdom. Contents Preface ...................................... xi Acknowledgments ............................... xv Abstract ..................................... xvii 1 Introduction ................................. 1 1.1 Overview................................. 1 1.2 ProblemStatementandGoals . 3 1.3 SummaryofResearch.......................... 4 References .................................... 7 2 Review of Near-field Optics and Superlenses for Nano-imaging . 9 2.1 Introduction............................... 9 2.2 ApertureScanningNear-FieldMicroscopy . 12 2.2.1 ApertureSNOMConcept ................... 12 2.2.2 Near-fieldofasubwavelengthaperture . 13 2.2.3 ApertureSNOMprobes .................... 15 vii 2.2.4 Implementation ......................... 18 2.3 Apertureless Scanning Near-Field Microscopy . 19 2.3.1 AperturelessSNOMConcept . 19 2.3.2 Near-fieldofasharpprobe. 22 2.3.3 AperturelessSNOMprobes . 24 2.3.4 Application ........................... 25 2.4 Superlens for Sub-diffraction-limited Imaging . ...... 28 2.4.1 DevelopmentofSuperlenses . 28 2.4.2 Leveraging Superlensing and Near-field Optics for Imaging. 30 2.5 FutureOutlook ............................. 37 2.5.1 FutureResearchforSuperlensImaging . 37 2.6 Conclusion................................ 40 References .................................... 41 3 Bringing the ‘perfect lens’ into focus by near-perfect compensation of losses without gain media ....................... 75 3.1 Introduction............................... 75 3.2 Methods................................. 79 3.3 Results.................................. 87 3.4 Conclusion................................ 93 References .................................... 95 viii 4 Plasmonic superlens image reconstruction using intensity data . 105 4.1 Introduction............................... 105 4.2 ImagingTheoryandSimulation . 110 4.3 Results.................................. 119 4.4 DiscussionandConclusion . 127 References .................................... 129 5 Plasmonic Superlens Imaging Enhanced by Incoherent Active Convolved Illumination .......................... 139 5.1 Introduction............................... 139 5.2 Theoretical Description and Noise Characterization . ...... 142 5.3 ImagingSimulation........................... 147 5.4 ResultsandDiscussion . 150 5.5 Conclusion................................ 160 References .................................... 162 6 Enhanced Lateral Spatial Resolution in Far-field Imaging .... 177 6.1 Introduction............................... 177 6.2 Theory.................................. 179 6.2.1 IncoherentImaging . 179 6.2.2 DetectionandNoise ...................... 181 6.2.3 TailoringtheSpectralSNR . 184 ix 6.3 Experiment ............................... 187 6.4 Results.................................. 190 6.4.1 Point Spread Functions and Transfer Functions . 190 6.4.2 SpectralSNR .......................... 190 6.4.3 TestImages ........................... 193 6.5 Discussion................................ 196 6.5.1 PixelSaturation......................... 196 6.5.2 RelationshiptoPreviousWorks . 197 6.6 An application to Superresolution Imaging . .. 199 6.6.1 Far-fieldSuperlensing. 199 6.6.2 Theory.............................. 200 6.6.3 DesignandSimulation . 202 6.7 Conclusion................................ 207 References .................................... 208 A Letters of Permission ........................... 213 A.1 Permission to reprint the article from AIP Advances ......... 213 A.2 Permission to reprint the article from New Journal of Physics ... 220 A.3 Permission to reprint the article from Journal of the Optical Society of America B ................................ 222 A.4 Permission to reprint the article from ACS Photonics ........ 226 x Preface This dissertation is mostly comprised of the four published articles in Chapters 2-5. Permissions to reuse the published articles have been obtained from the publishers, and letters of permission can be found in Appendix A. The majority of Chapter 6 is a draft of a paper which will be submitted for publication later. The main contributions by the author to this research and to the body of knowledge are: 1. The theory and simulation of the proposed loss mitigation and resolution en- hancement methods for incoherent light. 2. The implementation, design, construction, and analysis of the experiment in Chapter 6 to verify the proposed methods and extend them to far-field imaging. 3. The spectral SNR equation (Eq. 6.16) which quantitatively shows how to ma- nipulate the pupil or transfer function of an imaging system to achieve a desired high spatial frequency SNR. The individual contributions for each chapter are as follows: xi 1Chapter 2: W. Adams performed the literature review, organized the paper, and wrote the body text. M. Sadatgol and D. G¨uney provided technical comments and edited the manuscript. 2Chapter 3: W. Adams and M. Sadatgol performed modeling and wrote data analysis code to obtain the primary results in the paper. W. Adams and M. Sadatgol organized the paper. W. Adams wrote the body text. X. Zhang and D. G¨uney provided technical comments. M. Sadatgol and D. G¨uney edited the manuscript. 3Chapter 4: W. Adams performed the modeling and data analysis to obtain the main results in the paper. W. Adams organized and wrote the paper. A. Ghoshroy and D. G¨uney provided technical comments. D. G¨uney edited the manuscript. 4Chapter 5: W. Adams performed the modeling and data analysis to obtain the main results in the paper. W. Adams organized and wrote the paper. A. Ghoshroy and D. G¨uney provided technical comments. D. G¨uney edited the manuscript. Chapter 6: W. Adams, A. Ghoshroy, and D. G¨uney developed the underlying theory and core concepts. W. Adams constructed the experimental imaging system, collected 1W. Adams, M. Sadatgol, and D. O.¨ G¨uney, “Review of Near-field Optics and Superlenses for Sub-diffraction-limited Nano-imaging,” AIP Advances 6, 100701 (2016). 2W. Adams, M. Sadatgol, X. Zhang, and D. O.¨ G¨uney, “Bringing the ‘perfect lens’ into focus by near-perfect compensation of losses without gain media,” New Journal of Physics 18, 125004 (2016). 3W. Adams, A. Ghoshroy, and D. O.¨ G¨uney, “Plasmonic superlens image reconstruction using intensity data and equivalence to structured light illumination for compensation of losses,” Journal of the Optical Society of America B 34, 2161-2168 (2017). 4W. Adams, A. Ghoshroy, and D. O.¨ G¨uney, ”Plasmonic Superlens Imaging Enhanced by Incoherent Active Convolved Illumination,” ACS Photonics 5, 1294-1302 (2018). xii experimental data, performed modeling, designed the superlensing device, performed all data and image processing, and wrote the chapter text. C. Kendrick printed the spatial filter transparencies for the experimental imaging system. C. Middlebrook provided the lab space and some of the optics equipment to obtain the experimental results. xiii Acknowledgments I would like to express my gratitude to everyone at Michigan Technological University who has enabled me to pursue a PhD. Deserving of acknowledgement are my fellow students at Michigan Tech who have inspired and assisted this work through fruitful discussion, critique, and instruction, including Dr. Ankit Vora, Dr. Mehdi Sadatgol, Dr. Xu Zhang, Anindya Ghoshroy, Jiemin Zhang, James Davis, Michael Briseno, Michael Maurer, and Evan Gawron. I would like to thank Dr. Paul Bergstrom, Dr. Christopher Middlebrook, and Dr. Miguel Levy for agreeing to serve on my dissertation committee. Additionally I wish to thank Dr. Middlebrook for generously allowing me to use his lab space and optics equipment for a portion of this work. A special thank you is reserved for my PhD advisor, Dr. Durdu G¨uney, for his unrelenting support and guidance throughout the entirety of my graduate studies. He has taught me to not be too quick to doubt my ideas, even when they at first seem insignificant or far-fetched. I have never met such a forward-thinking person as him, a trait which I have found genuinely inspiring. Finally, I owe a deep debt of gratitude to my family and friends. Their positive xv contribution to my life, and consequently this work, is something I simply cannot even hope to