Metrics for High-Quality Specular Surfaces Book

	Preface	xi
	List of Abbreviations	xiii
	List of Symbols	xiv
Chapter 1	Surface Metrics	1
1.1	Introduction	1
1.2	Why Measure Surfaces?	4
1.2.1	System function	4
1.2.2	Appearance	5
1.2.3	Manufacturing efficiency	6
1.2.4	Benefits	6
1.3	Definition of Surface Metrics	6
1.3.1	Surface metrics influencing quality	8
1.3.2	Causes of defects in surface topography	9
1.4	Chapter Conclusions	10
	References	10
Chapter 2	Surface Form	13
2.1	Introduction	13
2.2	Optical Height Probes	14
2.3	Optical Slope Probe	16
2.4	Interferometers	16
2.4.1	Twyman-Green interferometer	17
2.4.2	Laser Fizeau interferometer	18
2.4.3	Four-step measurement of phase	19
2.4.4	Interlaboratory comparison of interferometers	21
2.4.5	Interferometer error sources and calibration	21
2.5	Form Tolerances	23
2.5.1	Approximating a spherical surface	25
2.5.2	Sagitta error	25
2.5.3	Irregularity function	25
2.5.4	Irregularity	25
2.5.5	Approximating an aspheric surface	25
2.5.6	Rotationally symmetric irregularity	25
2.5.7	Total RMS deviation (RMS[subscript t])	26
2.5.8	RMS irregularity (RMS[subscript i])	26
2.5.9	RMS asymmetry (RMS[subscript a])	26
2.5.10	Form indication on drawings	26
2.6	Chapter Conclusions	26
	References	27
Chapter 3	Surface Roughness	29
3.1	Introduction	29
3.2	Typical Optical Component Roughness Values	31
3.3	Deterministic Methods	32
3.3.1	Stylus method	33
3.3.2	Profilometry metrics	33
3.3.3	Microinterferometer	34
3.4	Parametric Methods	34
3.4.1	Surface point spread functions	34
3.4.2	Total integrated scatter measurement	36
3.5	Surface Roughness Indications in Drawings	37
3.6	Chapter Conclusions	37
	References	39
Chapter 4	Surface Waviness	41
4.1	Introduction	41
4.2	Fourier Analysis of Height Profile	43
4.3	Spatial Frequency Zones	43
4.4	Computation of Texture	43
4.5	Chapter Conclusions	45
	References	45
Chapter 5	Surface Imperfections	47
5.1	Introduction	47
5.2	Imperfections and Subconscious Thoughts	49
5.3	Effect of Surface Imperfections	49
5.4	Impact of Imperfections on Market Access	50
5.5	Description of Imperfections	51
5.5.1	Terminology	51
5.5.2	Size of imperfections	51
5.5.3	Substrates/materials	51
5.5.4	Location	51
5.5.5	Characteristics	52
5.6	Influence of Imperfections on Quality	52
5.6.1	Cosmetic influence	52
5.6.2	Functional influence	52
5.7	Causes of Imperfections	53
5.8	Reduction of Damage	53
5.9	Imperfection Measurement	54
5.9.1	Why measure imperfections?	54
5.9.2	Characterization and measurement of imperfections	54
5.10	Comparison of Measurement Methods	55
5.11	Imperfection Size Versus Visibility	56
5.11.1	Surface step as an imperfection	56
5.11.2	Step measurement by interferometry	58
5.12	The Eye as a Sensor	58
5.12.1	Benefits	58
5.12.2	Disbenefits	59
5.13	Disbenefits of Inspection	59
5.14	National Standards for Scratch Assessment	60
5.14.1	United States	60
5.14.2	Germany	61
5.14.3	France	61
5.14.4	United Kingdom	61
5.15	Level of Agreement Achieved Using National Standards	61
5.16	Scratch Reference Standards	63
5.17	Target Specification for Imperfection Measurement	65
5.18	Need for Standards	66
5.19	ISO TC 172 Optics and Optical Instruments	66
5.20	Comparison of Two Methods Proposed by ISO in 1996	67
5.20.1	Method I	67
5.20.2	Method II	67
5.20.3	Comparison of Methods I and II	67
5.21	Chapter Conclusions	68
	References	68
Chapter 6	Measurement of Imperfections by Obscuration	71
6.1	Introduction	71
6.2	Optical Component Inspection	71
6.3	Radiometric Obscuration by Imperfections	71
6.4	Calibration Graticules	73
6.5	LEW and SED Measurement Requirements	74
6.6	LEW and SED Simple Viewing System	74
6.7	Analogue Microscope Image Comparator (AMIC)	75
6.7.1	Description	75
6.7.2	Theory	77
6.7.3	Method of operation	78
6.8	Digital Microscope Image Comparator (DMIC)	79
6.8.1	Description	79
6.8.2	Results and discussion	83
6.9	Chapter Conclusions	84
	References	84
Chapter 7	Surface Imperfection Quality Control	85
7.1	Introduction	85
7.2	Survey of Tolerances	85
7.2.1	British Standard BS4301 (1991)	85
7.2.2	American Standard MIL-O-13830A:1963	86
7.2.3	German Standard DIN 3140: Part 7, 1978	86
7.2.4	French Standard	86
7.3	Acceptable Thresholds for Scratches and Roughness	87
7.4	Inspection and Measurement Flow Diagram	89
7.5	Chapter Conclusions	90
	References	91
Chapter 8	Far-Field Nanoscopy	93
8.1	Introduction	93
8.2	Comparison between Subjective and Objective Measurements of Imperfections	93
8.3	Relative Contrast of Standard Scratches	94
8.4	Measurement of Imperfections and Contamination in Assemblies	96
8.5	Measurement of Imperfections in Coatings	100
8.6	Use of MIC to Measure Surface Texture	101
8.7	Use of MIC to Examine Phase Objects	107
8.8	Use of MIC in AC Mode	111
8.9	Use of MIC On-Machine	114
8.10	Chapter Conclusions	115
	References	116
Chapter 9	Strip Product Inspection	117
9.1	Introduction	117
9.2	Laser Beam Scanners	118
9.3	Camera Inspection Systems	122
9.4	Chapter Conclusions	123
	Acknowledgment	124
	References	124
Appendix 1	Quality Metrics for Digital Cameras	125
Appendix 2	Surface Cleaning	135
	Glossary	139
	Contacts and Further Reading	145
	Index	147