Quasioptical Systems & Components for Terahertz Astronomy Item Type text; Electronic Dissertation Authors Golish, Dathon R Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 06/10/2021 06:08:18 Link to Item http://hdl.handle.net/10150/195891 QUASIOPTICAL SYSTEMS & COMPONENTS FOR TERAHERTZ ASTRONOMY by Dathon R Golish ________________________ A Dissertation Submitted to the Faculty of the DEPARTMENT OF OPTICAL SCIENCES In Partial Fulfillment of Requirements For the Degree of DOCTOR OF PHILOSOPHY In the Graduate College THE UNIVERSITY OF ARIZONA 2008 2 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE As members of the Dissertation Committee, we certify that we have read the dissertation prepared by Dathon R Golish entitled Quasioptical Systems and Components for Terahertz Astronomy and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Doctor of Philosophy _______________________________________________________________________ Date: 8/6/08 Christopher Walker, Dissertation Director _______________________________________________________________________ Date: 8/6/08 James Burge, Member _______________________________________________________________________ Date: 8/6/08 Mahmoud Fallahi, Member _______________________________________________________________________ Date: _______________________________________________________________________ Date: Final approval and acceptance of this dissertation is contingent upon the candidate’s submission of the final copies of the dissertation to the Graduate College. I hereby certify that I have read this dissertation prepared under my direction and recommend that it be accepted as fulfilling the dissertation requirement. ________________________________________________ Date: 8/6/08 Dissertation Director: Christopher Walker 3 STATEMENT BY AUTHOR This dissertation has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the head of the major department or the Dean of the Graduate College when in his or her judgment the proposed use of the material is in the interests of scholarship. In all other instances, however, permission must be obtained from the author. SIGNED: Dathon Golish 4 ACKNOWLEGMENTS No project, let alone projects of the size and diversity I have had the privilege to work on in SORAL over the past eight years, can be done by any one person. They all required a large network of people from many institutions with varied talents and areas of expertise. I owe each and everyone one of them a great deal of gratitude for allowing me to play in their sandbox. Most importantly, I owe great thanks to my advisor, Christopher Walker, for pulling me out of Popeye’s Chicken & Biscuits and into to the world of submillimeter astronomy. He has guided my educational career for almost a decade now, and I can absolutely say I would not be where I am without his advice and support. He is that extraordinary type of advisor who can shield his students from the horrors of funding and politics, while still pushing them to grow and succeed. My SORAL friends have been instrumental to the success of the work described here. Chris Groppi could make a receiver work in a dark room with only a rubber band and a toothpick. I have yet to ask Craig Kulesa a question he couldn’t answer, and he always does so with patience and genuine interest. No receiver has left SORAL without their prints on it and they are all better for it. In particular I must thank Christian d’Aubigny who has helped me from my first graduate class to the writing of this dissertation. He has always helped me any time I got stuck on this optical principle or that, and has been a remarkable advisor, employer, and friend. My thanks go out to every other SORAL member for their assistance – including Abby Hedden, Patrick Pütz, Paul Gensheimer, Mike Schein, Jenna Kloosterman, and Brian Duffy – and to the many other groups here at Arizona and at JPL, CalTech, Köln, Harvard, UMass, Northwestern, NASA, Virginia, and more. Thank you to my committee members – Jim Burge and Mahmoud Fallahi – for your advice in this final effort. Thank you to the support staffs at both OSC and Steward, you are all critical to any of us getting anything done. My graduate career has been made all the more interesting by participating in a new company. So to my friends at TeraVision – Abe Young, Doug Miller, James Gonnason, Bill Peters, and Robert & Anya Stickney – and to Christian and Chris Walker for leading us, thank you. I hope we all achieve great success with TeraVision, but either way it has been wonderful to work with you all. Graduate school is supposed to be the end of your social life, but for me it was the beginning of some lifelong friendships. I wouldn’t have made it through the homework and studying in our OpSci classes without Jenn Jannusch. Thank you for your friendship and for reminding me whether it’s sine or cosine in Snell’s law. Incredible thanks to Abby Hedden and Michael Stenner for being wonderful friends, Tucson is boring without you. And I can’t forget my climbing friends, my game night friends, and my D&D friends, thanks for getting me out of the lab! 5 DEDICATION To my family, the source of any success I have ever had or will have. To Gilbert and Rose, for never believing me when I said it was too hard. To Corwin and Zac, for giving me something to live up to. To Adam, for always caring about his brother, despite our different lives. And to Jodi and Dan, for teaching me how to be smart, how to be caring, how to be good, and that I will always be loved. 6 TABLE OF CONTENTS LIST OF FIGURES .............................................................................................................9 LIST OF TABLES.............................................................................................................19 ABSTRACT.......................................................................................................................20 CHAPTER 1 INTRODUCTION .....................................................................................21 1.1 Motivation: Remote Sensing Applications ......................................................22 1.1.1 Far-IR Astronomy......................................................................................22 1.1.2 Array Development....................................................................................25 1.1.3 Security......................................................................................................26 1.1.4 Medical......................................................................................................27 1.2 Geometric vs. Gaussian Optics........................................................................28 1.3 Gaussian Beam Propagation............................................................................30 1.3.1 Paraxial Wave Equation.............................................................................30 1.3.2 Complex Beam Parameter .........................................................................31 1.3.3 Propagation Equations...............................................................................34 1.3.4 Edge Taper.................................................................................................36 1.3.5 Confocal Distance......................................................................................37 1.3.6 Far-field Divergence Angle .......................................................................38 1.3.7 Beam Coupling..........................................................................................39 1.4 Summary..........................................................................................................41 CHAPTER 2 GAUSSIAN BEAM SYSTEMS................................................................42 2.1 Telescopes........................................................................................................42 2.1.1 Efficiency...................................................................................................43 2.2 Detectors ..........................................................................................................45 2.3 Local Oscillator................................................................................................48 2.3.1 Quasioptical Injection................................................................................48 2.3.2 Waveguide Injection..................................................................................54 2.4 Mirrors & Lenses .............................................................................................55 2.5 Feedhorns.........................................................................................................57 2.5.1 Diagonal Horn............................................................................................59