Field Guide to Optical Fabrication

Description

Whether you're an optical designer, optician, shop manager, or optics procurer, a working knowledge of optical fabrication can be invaluable. Have the information at your fingertips with this new Field Guide.

In Field Guide to Optical Fabrication, Ray Williamson distills the extensive knowledge gained from his long career—ranging from his work at the Optical Sciences Center at the University of Arizona to positions at Spectra-Physics, Coherent, and Los Alamos National Lab—into a ready reference for anyone needing to understand optical fabrication.

This Field Guide is a concise reference explaining:

• What every designer should know about fabrication before making final design choices
• How to specify components before they are ordered
• The details of conventional, alternative, and emerging fabrication methods
• How an optical manufacturer plans the work, evaluates product, and the calculations involved

Table of Contents

• Glossary of Symbols and Acronyms
• Introduction for Designers
• From Functional Desires to Component Tolerances
• Clear Aperture
• Thickness versus Stability and Ease of Fabrication
• Flatness versus Transmitted Wavefront
• Scale Factors for Surface and Wavefront
• Wedge in Nearly Concentric Optics
• Surface Quality versus Performance
• "Difficult" and Preferred Materials
• Pressure-Bearing Window Thickness
• Specifications Checklist
• Realistic Tolerances
• Designing Aspheres for Manufacturability
• What Kind of Shop Is It?
• Conventional Fabrication Methods
• Stages of Conventional Fabrication
• Shop Safety
• Blocking Layout
• Blocking Methods
• Pitch Pickup Blocking
• Spot Blocks
• Wedge Tools
• Sawing
• Milling
• Curve Generating
• Free-Abrasive Grinding
• Abrasive Types and Grades
• Fixed-Abrasive Lapping
• Beveling
• Dicing
• Coring and Drilling
• Edging
• Centerless Edging
• Centering
• Fractures, Chips, and Stoning
• Marking: Spot Bevels, Dots, Arrows, etc.
• Polishing
• Polishing Compounds
• Pitch Laps: Channels and Figure Control
• Polishing Pads
• Crystal Shaping and Orientation
• Crystal Lapping
• Overarm Spindle Machine
• Stick Lens Fabrication
• Planetary Lapping
• Double-Side Lapping
• Cylindrical and Toric Lapping
• Intrashop Transporting and Storage
• In-Process Cleaning
• Cleaning for Thin-Film Coating
• Thin-Film Coating
• Assembly
• Packaging for Shipping
• Alternative Fabrication Methods
• CNC with Spindle-Mounted Tools
• CNC Synchrospeed Polisher
• CNC Belt Style Machine
• CNC Bonnet Polisher
• Magnetorheological Fluid Finishing
• Fluid Jet Polishing (FJP)
• Single-Point Diamond Turning (SPDT)
• Replication
• Plastic Injection Molding
• Thermoset Casting and Compression Molding
• Hot Pressing
• Process-Planning Factors
• Raw Material and Forms of Supply
• Starting Material Dimensions
• Yield from Dicing and Coring
• Efficient Production and Optimum Quantities
• Planning for Yield Losses
• Block Capacity: Flat
• Wedge Tool Capacity
• Block Capacity: Radius
• Scheduling for Coating
• Directional Inhomogeneity
• Stresses Within Optical Components
• Stresses Applied to Optical Components
• Thermal Settling Time
• Thermal Failure
• In-Process Inspection Points
• Dice After Coating?
• Cements and Adhesives
• Evaluation
• Sampling Inspection and Acceptance Quality Level (AQL)
• Cosmetic Surface Quality
• Angle Testing With an Autocollimator
• Sagitta and Spherometers
• Radius, Irregularity, Power, and Figure
• Interferometry
• Interferometric Setups
• PV, RMS, and PVr
• Fringe Patterns
• Fringe Scale Factors
• Conics and Aspheres
• Dimensional and Geometric Measurement
• Slope Evaluation Methods
• Slope Tolerancing
• Materials Properties
• Material Properties of Interest In the Shop
• Material Properties Table
• Optical Properties Table
• Physical Properties Table
• Thermal Properties Table
• Equation Summary
• Bibliography
• Index

PREFACE

Most Field Guides address a particular subset of physics and/or mathematics and, as such, can be treated in a linear exposition of theory from first principles. In contrast, optical fabrication consists of a collection of disparate crafts, technologies, and business decisions in the service of making nearly perfect physical instances of those geometric and physical theories. I have attempted to organize the subject matter in ways that make sense to me: What the designer needs to know before making final choices, how to specify the components before they are ordered, how conventional fabrication proceeds for representative components, alternative and emerging methods, how the manufacturer plans the work, product evaluation, and calculations used.

This Field Guide is intended to serve several audiences, and introduce each to the other. I hope to provide designers and purchasers with some perspectives and appreciation for the craft and business, the shop manager with a concise reference, the optician with a wider overview than one is likely to get within any single company, and the optical community at large with some insight into this fascinating and dynamic enterprise.

Thanks are due to Oliver Fähnle for inputs to synchrospeed and fluid jet. I want to particularly acknowledge three influences, true masters in the field: Dick Sumner, Norm Brown, and Frank Cooke. Dick personified excellence in craft, a passionate curiosity, and a focus on effectiveness. Norm brought the light of science and engineering to the hidden mysteries of this once-black art with accessible clarity. Frank was an inspiration to all through his boundless creativity and zest. We are in transition between 20th Century craft and 21st Century technology, and the field will be hardly recognizable in twenty years.

Ray Williamson
August 2011