Optomechanical Systems Engineering

Description

This book emphasizes a practical, systems-level overview of optomechanical engineering, showing throughout how the requirements on the optical system flow down to those on the optomechanical design. The author begins with an overview of optical engineering, including optical fundamentals as well as the fabrication and alignment of optical components such as lenses and mirrors. The concepts of optomechanical engineering are then applied to the design of optical systems, including the structural design of mechanical and optical components, structural dynamics, thermal design, and kinematic design.

Optomechanical Systems Engineering:

• Reviews the fundamental concepts of optical engineering as they apply to optomechanical design
• Illustrates the fabrication and alignment requirements typically found in an optical system
• Examines the elements of structural design from a mechanical, optical, and vibrational viewpoint
• Develops the thermal management principles of temperature and distortion control
• Describes the optomechanical requirements for kinematic and semi-kinematic mounts
• Uses examples and case studies to illustrate the concepts and equations presented in the book
• Provides supplemental materials on a companion website

Focusing on fundamental concepts and first-order estimates of optomechanical system performance, Optomechanical Systems Engineering is accessible to engineers, scientists, and managers who want to quickly master the principles of optomechanical engineering.

Contents

Preface

1 Introduction 1

• 1.1 Optomechanical Systems 2
• 1.2 Optomechanical Engineering 4
• 1.3 Optomechanical Systems Engineering 9
• References 15

2 Optical Fundamentals 17

• 2.1 Geometrical Optics 18
• 2.2 Image Quality 26
• Problems 33
• References 34

3 Optical Fabrication 35

• 3.1 Index of Refraction 39
• 3.2 Surface Curvature 41
• 3.3 Surface Figure 43
• 3.4 Surface Finish 48
• 3.5 Surface Quality 49
• 3.6 Center Thickness 50
• 3.7 Wedge 51
• 3.8 Clear Aperture 53
• Problems 54
• References 55

4 Optical Alignment 57

• 4.1 Types of Misalignments 58
• 4.1.1 Tilt 59
• 4.1.2 Decenter 61
• 4.1.3 Despace 62
• 4.1.4 Defocus 62
• 4.2 Alignment Requirements 64
• 4.3 Correction and Mitigation 66
• 4.4 Pointing and Boresighting 70
• Problems 75
• References 76

5 Structural Design: Mechanical Elements 77

• 5.1 Stress Strain and Stiffness 78
• 5.2 Mechanics 82
• 5.3 Beam Stresses and Strains 85
• 5.3.1 Bending Stresses 86
• 5.3.2 Bending Strain 89
• 5.3.3 Shear Stresses and Strains 94
• 5.4 Structural Geometries 95
• 5.5 Structural Materials 99
• 5.5.1 Specific Stiffness 100
• 5.5.2 Microcreep 102
• 5.5.3 Materials Selection 103
• Problems 104
• References 105

6 Structural Design: Optical Components 107

• 6.1 Structural Plates 109
• 6.1.1 Windows Lenses and Mirrors 109
• 6.1.2 Poisson’s Ratio 111
• 6.1.3 Plate Bending 113
• 6.1.4 Contact Stresses 115
• 6.1.5 Stress Concentrations 120
• 6.2 Glass Strength 122
• 6.2.1 Fracture Toughness 122
• 6.2.2 Weibull Statistics 126
• Problems 130
• References 131

7 Structural Design—Vibrations 133

• 7.1 Sinusoidal Vibrations 137
• 7.1.1 Free Vibrations 137
• 7.1.2 Forced Vibrations 140
• 7.1.3 Damping 142
• 7.2 Random Vibrations 146
• 7.3 Continuous Systems 150
• 7.4 Structural Design and Materials Selection 157
• 7.5 Vibration Isolation 159
• 7.6 Vibration Compensation 166
• Problems 168
• References 169

8 Thermal Design 171

• 8.1 Thermostructural Design 173
• 8.1.1 Thermal Expansion 173
• 8.1.2 Thermal Stress 178
• 8.2 Thermo ]Optic and Stress ]Optic Effects 181
• 8.2.1 Thermo ]Optic Effect 182
• 8.2.2 Stress ]Optic Effect 185
• 8.3 Heat Transfer 187
• 8.3.1 Conduction 187
• 8.3.2 Convection 193
• 8.3.3 Radiation 196
• 8.4 Thermal Management 201
• 8.4.1 Heaters 202
• 8.4.2 Fans 203
• 8.4.3 Thermal Interface Materials (TIMs) 203
• 8.4.4 Thermoelectric Coolers (TECs) 204
• 8.5 Material Properties and Selection 205
• 8.5.1 Thermal Expansion 206
• 8.5.2 Thermal Distortion 207
• 8.5.3 Thermal Mass 208
• 8.5.4 Thermal Diffusivity 209
• 8.5.5 Thermal Shock 210
• Problems 211
• References 212

9 Kinematic Design 215

• 9.1 Kinematic and Semi ]Kinematic Mounts 216
• 9.2 Optical Component Mounts 222
• 9.3 Positioning and Alignment Mechanisms 227
• 9.4 Material Properties and Selection 233
• Problems 235
• References 235

10 System Design 237

• 10.1 Stop Analysis 239
• 10.2 Wfe and Zernike Polynomials 243
• 10.3 Material Trades 246
• References 250

Index 251

Author

Keith J. Kasunic has more than 25 years of experience developing optical, electro-optical, infrared, and laser systems. He holds a Ph.D. in Optical Sciences from the University of Arizona, an MS in Mechanical Engineering from Stanford University, and a BS in Mechanical Engineering from MIT. He is currently the Technical Director of Optical Systems Group LLC. He also teaches courses on optomechanical engineering as an SPIE Instructor, an Affiliate Instructor with Georgia Institute of Technology’s SENSIAC, an Instructor for the Optical Engineering Certificate Program at University of California–Irvine, and an Adjunct Professor at University of Central Florida’s CREOL.