Optics For Dummies

Galen Duree, Jr., PhD, is Professor of Physics and Optical Engineering at Rose-Hulman Institute of Technology in Indiana, where he is also the Director of the Center for Applied Optics Studies. Duree jointly established the Ultrashort Pulse Laser Laboratory at RHIT and continues to work with the Navy.

• Introduction 1About This Book 1Conventions Used in This Book 2What You’re Not to Read 3Foolish Assumptions 3How This Book Is Organized 3Part I: Getting Up to Speed on Optics Fundamentals 4Part II: Geometrical Optics: Working with More Than One Ray 4Part III: Physical Optics: Using the Light Wave 4Part IV: Optical Instrumentation: Putting Light to Practical Use 4Part V: Hybrids: Exploring More Complicated Optical Systems 5Part VI: More Than Just Images: Getting into Advanced Optics 5Part VII: The Part of Tens 5Icons Used in This Book 5Where to Go from Here 6Part I: Getting Up to Speed on Optics Fundamentals 7Chapter 1: Introducing Optics, the Science of Light 9Illuminating the Properties of Light 9Creating images with the particle property of light 10Harnessing interference and diffraction with the wave property of light 10Using Optics to Your Advantage: Basic Applications 11Expanding Your Understanding of Optics 12Considering complicated applications 12Adding advanced optics 13Paving the Way: Contributions to Optics 13Chapter 2: Brushing Up on Optics-Related Math and Physics 15Working with Physical Measurements 15Refreshing Your Mathematics Memory 16Juggling variables with algebra 16Finding lengths and angles with trigonometry 18Exploring the unknown with basic matrix algebra 21Reviewing Wave Physics 26The wave function: Understanding its features and variables 26Medium matters: Working with mechanical waves 28Using wavefronts in optics 29Chapter 3: A Little Light Study: Reviewing Light Basics 31Developing Early Ideas about the Nature of Light 31Pondering the particle theory of light 32Walking through the wave theory of light 32Taking a Closer Look at Light Waves 33If light is a wave, what’s waving? Understanding electromagnetic radiation 33Dealing with wavelengths and frequency: The electromagnetic spectrum 36Calculating the intensity and power of light 36Einstein’s Revolutionary Idea about Light: Quanta 37Uncovering the photoelectric effect and the problem with light waves 38Merging wave and particle properties: The photon 39Let There Be Light: Understanding the Three Processes that Produce Light 40Atomic transitions 40Accelerated charged particles 41Matter-antimatter annihilation 42Introducing the Three Fields of Study within Optics 42Geometrical optics: Studying light as a collection of rays 42Physical optics: Exploring the wave property of light 43Quantum optics: Investigating small numbers of photons 43Chapter 4: Understanding How to Direct Where Light Goes 45Reflection: Bouncing Light Off Surfaces 45Determining light’s orientation 46Understanding the role surface plays in specular and diffuse reflection 47Appreciating the practical difference between reflection and scattering 48Refraction: Bending Light as It Goes Through a Surface 50Making light slow down: Determining the index of refraction 50Calculating how much the refracted ray bends: Snell’s law 51Bouncing light back with refraction: Total internal reflection 52Varying the refractive index with dispersion 53Birefringence: Working with two indices of refraction for the same wavelength 54Diffraction: Bending Light around an Obstacle 55Part II: Geometrical Optics: Working with More Than One Ray 57Chapter 5: Forming Images with Multiple Rays of Light 59The Simplest Method: Using Shadows to Create Images 60Forming Images Without a Lens: The Pinhole Camera Principle 62Eyeing Basic Image Characteristics for Optical System Design 63The type of image created: Real or virtual 63The orientation of the image relative to the object 63The size of the image relative to the object 64Zeroing In on the Focal Point and Focal Length 65Determining the focal point and length 65Differentiating real and virtual focal points 66Chapter 6: Imaging with Mirrors: Bouncing Many Rays Around 69Keeping it Simple with Flat Mirrors 69Changing Shape with Concave and Convex Mirrors 70Getting a handle on the mirror equation and sign conventions 71Working with concave mirrors 72Exploring convex mirrors 74Chapter 7: Imaging with Refraction: Bending Many Rays at the Same Time 77Locating the Image Produced by a Refracting Surface 78Calculating where an image will appear 78Solving single-surface imaging problems 80Working with more than one refracting surface 83Looking at Lenses: Two Refracting Surfaces Stuck Close Together 85Designing a lens: The lens maker’s formula 85Taking a closer look at convex and concave lenses 88Finding the image location and characteristics for multiple lenses 89D’oh, fuzzy again! Aberrations 91Part III: Physical Optics: Using the Light Wave 95Chapter 8: Optical Polarization: Describing the Wiggling Electric Field in Light 97Describing Optical Polarization 97Focusing on the electric field’s alignment 98Polarization: Looking at the plane of the electric field 99Examining the Different Types of Polarization 100Linear, circular, or elliptical: Following the vector path 100Random or unpolarized: Looking at changing or mixed states 107Producing Polarized Light 108Selective absorption: No passing unless you get in line 108Scattering off small particles 109Reflection: Aligning parallel to the surface 110Birefringence: Splitting in two 111Chapter 9: Changing Optical Polarization 113Discovering Devices that Can Change Optical Polarization 113Dichroic filters: Changing the axis with linear polarizers 114Birefringent materials: Changing or rotating the polarization state 117Rotating light with optically active materials 121Jones Vectors: Calculating the Change in Polarization 121Representing the polarization state with Jones vectors 121Jones matrices: Showing how devices will change polarization 124Matrix multiplication: Predicting how devices will affect incident light 126Chapter 10: Calculating Reflected and Transmitted Light with Fresnel Equations 131Determining the Amount of Reflected and Transmitted Light 131Transverse modes: Describing the orientation of the fields 132Defining the reflection and transmission coefficients 133Using more powerful values: Reflectance and transmittance 134The Fresnel equations: Finding how much incident light is reflected or transmitted 135Surveying Special Situations Involving Reflection and the Fresnel Equations 136Striking at Brewster’s angle 137Reflectance at normal incidence: Coming in at 0 degrees 137Reflectance at glancing incidence: Striking at 90 degrees 138Exploring internal reflection and total internal reflection 138Frustrated total internal reflection: Dealing with the evanescent wave 139Chapter 11: Running Optical Interference: Not Always a Bad Thing 143Describing Optical Interference 143On the fringe: Looking at constructive and destructive interference 144Noting the conditions required to see optical interference 145Perusing Practical Interference Devices: Interferometers 146Wavefront-splitting interferometers 146Amplitude-splitting interferometers 151Accounting for Other Amplitude-Splitting Arrangements 154Thin film interference 154Newton’s rings 157Fabry-Perot interferometer 158Chapter 12: Diffraction: Light’s Bending around Obstacles 161From Near and Far: Understanding Two Types of Diffraction 162Defining the types of diffraction 162Determining which type of diffraction you see 163Going the Distance: Special Cases of Fraunhofer Diffraction 164Fraunhofer diffraction from a circular aperture 165Fraunhofer diffraction from slits 167Getting Close: Special Cases of Fresnel Diffraction 172Fresnel diffraction from a rectangular aperture 173Fresnel diffraction from a circular aperture 174Fresnel diffraction from a solid disk 175Diffraction from Fresnel zone plates 175Part IV: Optical Instrumentation: Putting Light to Practical Use 179Chapter 13: Lens Systems: Looking at Things the Way You Want to See Them 181Your Most Important Optical System: The Human Eye 181Understanding the structure of the human eye 182Accommodation: Flexing some muscles to change the focus 183Using Lens Systems to Correct Vision Problems 185Corrective lenses: Looking at lens shape and optical power 185Correcting nearsightedness, farsightedness, and astigmatism 186Enhancing the Human Eye with Lens Systems 190Magnifying glasses: Enlarging images with the simple magnifier 191Seeing small objects with the compound microscope 192Going the distance with the simple telescope 194Jumping to the big screen: The optical projector 195Chapter 14: Exploring Light Sources: Getting Light Where You Want It 197Shedding Light on Common Household Bulbs 198Popular bulb types and how they work 198Reading electrical bulb rates 201Shining More-Efficient Light on the Subject: Light Emitting Diodes 201Looking inside an LED 202Adding color with organic light emitting diodes 203LEDs on display: Improving your picture with semiconductor laser diodes 204Zeroing in on Lasers 205Building a basic laser system 206Comparing lasers to light bulbs 211Chapter 15: Guiding Light From Here to Anywhere 213Getting Light in the Guide and Keeping it There: Total Internal Reflection 213Navigating numerical aperture: How much light can you put in? 214Examining light guide modes 215Categorizing Light Guide Types 216Fiber-optic cables 216Slab waveguides 220Putting Light Guides to Work: Common Applications 221Light pipes 221Telecommunication links 221Imaging bundles 224Part V: Hybrids: Exploring More Complicated Optical Systems 227Chapter 16: Photography: Keeping an Image Forever 229Getting an Optical Snapshot of the Basic Camera 230Lens: Determining what you see 231Aperture: Working with f-number and lens speed 234Shutter: Letting just enough light through 236Recording media: Saving images forever 236Holography: Seeing Depth in a Flat Surface 237Seeing in three dimensions 237Exploring two types of holograms 238Relating the hologram and the diffraction grating 240Graduating to 3-D Movies: Depth that Moves! 243Circular polarization 243Six-color anaglyph system 244Shutter glasses 244Chapter 17: Medical Imaging: Seeing What’s Inside You (No Knives Necessary!) 247Shining Light into You and Seeing What Comes Out 247X-rays 248Optical coherence tomography 250Endoscopes 251Reading the Light that Comes Out of You 253CAT scans 254PET scans 255NMR scans 256MRI scans 257Chapter 18: Optics Everywhere: Exploring Other Medical, Industrial, and Military Uses 259Considering Typical Medical Procedures Involving Lasers 259Removing stuff you don’t want: Tissue ablation 260Sealing up holes or incisions 263Purely cosmetic: Doing away with tattoos, varicose veins, and unwanted hair 264Getting Industrial: Making and Checking Products Out with Optics 265Monitoring quality control 265Drilling holes or etching materials 265Making life easier: Commercial applications 266Applying Optics in Military and Law Enforcement Endeavors 267Range finders 267Target designation 268Missile defense 268Night vision systems 269Thermal vision systems 270Image processing 270Chapter 19: Astronomical Applications: Using Telescopes 271Understanding the Anatomy of a Telescope 272Gathering the light 272Viewing the image with an eyepiece 273Revolutionizing Refracting Telescopes 274Galilean telescope 275Kepler’s enhancement 276Reimagining Telescope Design: Reflecting Telescopes 277Newtonian 277Cassegrain 278Gregorian 279Hybrid Telescopes: Lenses and Mirrors Working Together 280Schmidt 280Maksutov 281Invisible Astronomy: Looking Beyond the Visible 282When One Telescope Just Won’t Do: The Interferometer 283Part VI: More Than Just Images: Getting into Advanced Optics 285Chapter 20: Index of Refraction, Part 2: You Can Change It! 287Electro-Optics: Manipulating the Index of Refraction with Electric Fields 287Dielectric polarization: Understanding the source of the electro-optic effect 288Linear and quadratic: Looking at the types of electro-optic effects 289Examining electro-optic devices 293Acousto-Optics: Changing a Crystal’s Density with Sound 295The acousto-optic effect: Making a variable diffraction grating 295Using acousto-optic devices 296Frequency Conversion: Affecting Light Frequency with Light 297Second harmonic generation: Doubling the frequency 297Parametric amplification: Converting a pump beam into a signal beam 298Sum and difference frequency mixing: Creating long or short wavelengths 299Chapter 21: Quantum Optics: Finding the Photon 301Weaving Together Wave and Particle Properties 301Seeing wave and particle properties of light 302Looking at wave and particle properties of matter 304Experimental Evidence: Observing the Dual Nature of Light and Matter 306Young’s two-slit experiment, revisited 306Diffraction of light and matter 307The Mach-Zehnder interferometer 308Quantum Entanglement: Looking at Linked Photons 308Spooky action: Observing interacting photons 308Encryption and computers: Developing technology with linked photons 309Part VII: The Part of Tens 311Chapter 22: Ten Experiments You Can Do Without a $1-Million Optics Lab 313Chromatic Dispersion with Water Spray 313The Simple Magnifier 314Microscope with a Marble 314Focal Length of a Positive Lens with a Magnifying Glass 314Telescope with Magnifying Glasses 315Thin Film Interference by Blowing Bubbles 316Polarized Sunglasses and the Sky 316Mirages on a Clear Day 317Spherical Aberration with a Magnifying Glass 317Chromatic Aberration with a Magnifying Glass 318Chapter 23: Ten Major Optics Discoveries — and the People Who Made them Possible 319The Telescope (1610) 319Optical Physics (Late 1600s) 320Diffraction and the Wave Theory of Light (Late 1600s) 320Two-Slit Experiment (Early 1800s) 321Polarization (Early 1800s) 321Rayleigh Scattering (Late 1800s) 321Electromagnetics (1861) 322Electro-Optics (1875 and 1893) 322Photon Theory of Light (1905) 322The Maser (1953) and The Laser (1960) 323Index 325