Table of Contents

Fundamentals of Thin Film Optics

• 1.1. INTRODUCTION 1
• 1.2. REVIEW OF THIN FILM OPTICS PRINCIPLES 5
• 1.3. REFLECTANCE DIAGRAMS AND DESIGN 12
• 1.3.1. Low Reflectors, Antireflection Coatings 15
• 1.3.2. Physical Thickness versus Optical Thickness 22
• 1.3.3. Three-Layer AR Coating on Germanium, Example 22
• 1.3.4. Example Four-Layer Broad Band AR Coating in the Visible 26
• 1.3.5. Behavior of a High Index Slab 27
• 1.3.6. High Reflectors 29
• 1.3.7. Beamsplitters 36
• 1.3.8. Higher Harmonic Reflection Bands 36
• 1.3.9. Minus Filters and Narrow Blocking Bands 39
• 1.3.10. Another Approach to Narrow Blocking Bands 41
• 1.3.11. Fencepost and Posthole Design Approaches 42
• 1.4. APPROXIMATIONS OF INDICES AND DESIGNS 46
• 1.4.1. Herpin/Epstein Periods 46
• 1.4.2. More General Approximations 48
• 1.5. INHOMOGENEOUS INDEX FUNCTIONS 51
• 1.5.1. Step-Down Functions 52
• 1.5.2. Low Index Limitations 59
• 1.5.3. Lithographic “Moth-Eye” ARs 61
• 1.5.4. Overcoming Low Index Limitations With Thickness 63
• 1.5.5. Additional Thickness Functions 63
• 1.5.6. A Fourier Approach 69
• 1.5.7. Rugates and the EUV/Soft X-ray Spectral Region 74
• 1.5.8. Potential Quantization Effects in Designs for EUV Mirrors 86
• 1.6 ANGLES AND POLARIZATION 92
• 1.6.1. Wavelength Shift with Angle of Incidence 92
• 1.6.2. Polarization Effects of Angle of Incidence 93
• 1.6.3. Polarization as Seen in Reflectance Amplitude Diagrams 96
• 1.6.4. Polarizing Beamsplitters 99
• 1.6.5. Non-Polarizing Beamsplitters 102
• 1.7. ADDITIONAL VIEWS VIA GRAPHICS AND PLOTS 106
• 1.7.1. Admittance Diagrams 106
• 1.7.2. Ellipsometry Plots 109
• 1.7.3. Additional Graphics for Visualization 117
• 1.8. TRIANGLE DIAGRAMS AND DESIGN 118
• 1.8.1. Designing Coatings with Absorbing Materials 121
• 1.8.2. Induced Transmission Filter Example 131
• 1.8.3. NBP Reflection Filter Example 134
• 1.8.4. AR Coated Variable Neutral Density Filter Example 137
• 1.8.5. Conclusions of Designing With Metals 142
• 1.9. NARROW BANDPASS FILTERS 142
• 1.9.1. NBP Wavelength Effects as Seen on Reflectance Diagrams 149
• 1.9.2. Dense Wavelength Division Multiplexing (DWDM) Filters 152
• 1.9.3. Fiber Bragg Gratings 155
• 1.10. FENCEPOST DESIGN EXAMPLES 155
• 1.10.1. Edge Filters 158
• 1.10.2. Fencepost Narrow Bandpass Filters 160
• 1.11. OPTIMIZATION 163
• 1.11.1. Performance Goals and Weightings 164
• 1.11.2. Global versus Local Minima 165
• 1.11.3. Some Optimizing Concepts 166
• 1.11.4. Constraints 171
• 1.11.5. Quantization 173

Estimating What Can Be Done Before Designing

• 2.1. INTRODUCTION 181
• 2.2. ANTIREFLECTION COATINGS 181
• 2.2.1. Procedure 182
• 2.2.2. The Formula 183
• 2.2.3. Results 185
• 2.2.4. Berlin AR Design Contest 189
• 2.2.5. Results of Further Study 191
• 2.2.6. Estimating the Number of Layers 197
• 2.2.7. Looking Outside the Box 199
• 2.2.8. Reverse Engineering Using Number of Ripples in Band 203
• 2.3. BANDPASS AND BLOCKER COATINGS 204
• 2.3.1. Estimating the Width of a Blocking Band 204
• 2.3.2. Estimating the Optical Density of a Blocking Band 206
• 2.3.3. Estimating the Number of Layers and Thickness Needed 207
• 2.3.4. Estimating More Complex Coatings 208
• 2.3.5. Estimating Edge Filter Passband Reflection Losses 214
• 2.4. DICHROIC REFLECTION COATINGS 223
• 2.5. DWDM FILTERS 225
• 2.6. ESTIMATING OD AND BW OF FENCEPOSTS 230

Fourier Viewpoint of Optical Coatings

• 3.1. INTRODUCTION 237
• 3.2. FOURIER CONCEPTS 237
• 3.2.1. Background 239
• 3.2.2. Some Limitations 247
• 3.2.3. A Method to Determine the Multiple Reflections 253

AR Coating Design Example

• C.1. DESIGNING A VBBAR 279
• C.2. OTHER EXAMPLES 291
• C.3. REFERENCES 294

Color Measurement, Introduction

• D.1. WHAT IS COLOR MEASUREMENT? 297