Short Courses

Optical Fabrication and Testing (OF&T)



Optical Fabrication and Testing (OF&T)

22 - 26 June 2014
The Fairmont Orchid, Kohala Coast, Hawaii, USA

Short Courses

Short Courses cover a broad range of topic areas at a variety of educational levels (introductory to advanced). The courses are taught by highly regarded industry experts in a variety of specialties. Short Courses are an excellent opportunity to learn about new products, cutting-edge technology and vital information at the forefront of your field. They are designed to increase your knowledge of a specific subject while offering you the experience of knowledgeable teachers.

Certificate of Attendances are available for those who register and attend a course. To request a Certificate of Attendance after the conference, please email cstech@osa.org with your name, the course name, conference name, and year.
 
Each Short Course requires a separate fee. Paid registration includes admission to the course and one copy of the Short Course Notes. Advance registration is advisable. The number of seats in each course is limited, and on-site registration is not guaranteed.


Classical Optics 2014 Short Course Schedule

Sunday, 22 June, 09:00-12:00
SC415 Making Sense of Waviness and Roughness on Optics
SC418 Optical Materials, Fabrication and the Testing for the Optical Engineer

Sunday, 22 June, 13:00-16:00
SC414 Understanding Scratch and Dig Specifications
SC416 Practical Aspects of Measurement Uncertainty, Calibration, Traceability and Accreditation

Sunday, 22 June, 17:00-20:00
SC417 Evaluating Aspheres for Manufacurability


2014 Short Course Descriptions


SC414 Understanding Scratch and Dig Specifications

Dave Aikens, Savvy Optics Corp, USA
Sunday, 22 June, 13:00 - 16:00

Course Description
Surface imperfection specifications (i.e. Scratch-Dig) are among the most misunderstood, misinterpreted, and ambiguous of all optics component specifications.  This course provides attendees with an understanding of the source of ambiguity in surface imperfection specifications, and provides the context needed to properly specify surface imperfections using a variety of specification standards, and to evaluate a given optic to a particular level of surface imperfection specification. The course will focus on the various interpretations of the MIL-PRF-13830, including its history and origin.  Attendees will also be introduced to ISO 10110-7, a dimensional based surface imperfection standard gaining popularity in Europe, and ANSI/OEOSC OP1.002, the American National Standard for surface imperfections on optics which includes methods of specifying either scratch-dig or a dimensional specification. Many practical and useful specification examples are included throughout, as well as demonstration of visual comparison evaluation techniques and artifacts.

Benefits and Learning Objectives
This course should enable participants to:
  • Describe the various surface imperfection specifications that exist today
  • Compose a meaningful surface imperfection specification for cosmetic imperfections using ISO, ANSI, or MIL standards
  • Identify the different illumination methods and comparison standards for evaluation
  • Demonstrate a surface imperfection visual inspection
  • Understand the options available for controlling surface imperfections in a vendor/supplier relationship
Intended Audience
This material is intended for anyone who needs specify, quote, or evaluate optics for surface imperfections. No industry experience is required; the course is benefitial to both newcomers and veterans of the industry. Those who either design their own optics or who are responsible for optics purchasing or quality control will find this course valuable.
 
Instructor Biography
Dave Aikens, a.k.a. “the scratch guy” is President and founder of Savvy Optics Corp., and has been involved in optics specifications for over 20 years. He is considered one of the foremost experts in optics surface imperfections in the world today. He is the head of the American delegation to ISO TC 172 SC1, and is Executive Director of the Optics and Electro-Optics Standards Council, OEOSC.

SC415 Making Sense of Waviness and Roughness on Optics

Dave Aikens, Savvy Optics Corp, USA
Sunday, 22 June, 09:00 - 12:00

Course Description
The surface texture of a polished optical surface is an important, if misunderstood, surface property. This course is designed to bring photonics personnel up to an immediate working knowledge on surface texture specifications and the impact surface roughness and waviness can have on an optical system.  Surface roughness causes scatter and system transmission loss, while waviness and mid-spatial frequency ripple can cause loss of resolution, image quality, veiling glare, beam modulation and a host of other issues.
 
Until recently, surface texture could be safely described by a single number, RMS roughness, following MIL-STD-10A, since most polished optical surfaces were manufactured using the same slurry-pitch process that had existed for decades. In the past 30 years, however, new manufacturing technologies have evolved using molding, diamond turning, synthetic lap polishing and deterministic figuring which have dramatically altered the surface finish of optics. In order to control the resultant surface texture errors, new specifications like gradients, correlation values, PSDs and MSF waviness specifications have been introduced. Most users do not completely understand these new notations however, and the meaning of even a simple RMS roughness specification has become obscure, or even meaningless.
 
The course defines the terms and parameters used to control surface texture in the modern optical manufacturing world. The potential performance impact of surface texture errors will be covered, and some specific case studies will be used to show the impact of various amplitudes of these errors on precision optical instrument performance. The national and international standards are introduced, and the derivation of meaningful specification for texture and waviness for common applications is discussed. Finally, the identification, measurement and reduction of these manufacturing errors is treated.

Benefits and Learning Objectives
This course should enable participants to:
  • Describe the surface texture of a polished optical surface based on its specifications
  • Understand the meaning of a Power Spectral Density plot
  • Quantify the requirements for surface texture using PSD and gradient notations
  • Predict the impact of mid-spatial frequency ripple and roughness on system performance
  • Compose a meaningful surface texture specification for both waviness and roughness
  • Identify waviness surface errors in measurement data
 
Intended Audience
This course is intended for engineers, managers and experienced technicians working in optical design, manufacturing, metrology and quality control and assurance.  Anyone who is responsible for specifying or interpreting surface roughness and waviness specifications will find it extremely useful. Some understanding of algebra is beneficial. 

Biography
Dave Aikens has been writing on the subject of surface texture and ripple for more than 20 years and is one of the foremost experts on optics mid-spatial frequency waviness today.  Dave is President and founder of Savvy Optics Corp., is the head of the American delegation to ISO TC 172 SC1, and is Executive Director of the Optics and Electro-Optics Standards Council. He also served as the project manager for the current ISO surface texture notation standards for optics.

SC416 Practical Aspects of Measurement Uncertainty, Calibration, Traceability, and Accreditation

Ulf Griesmann and Dr. Johannes A. Soons, NIST, USA
Sunday, 22 June, 13:00-16:00

Course Level
Advanced beginner - basic understanding of topic is necessary to follow the course material.

Course Description
Successful national and international trade is based on mutual understanding, trust, and verification. Standards organizations, trade associations, and professional societies have created a framework of standards that enables reliable exchange of information between trading partners. International and national measurement institutes provide the foundation for a single system of measurements throughout the world traceable to the International System of Units (SI).  We give an overview of this standards and metrology framework and describe its practical implications for the optics industry. We explain the central role of measurement uncertainty, calibrations, and check standards in a quality system for optical manufacturing and testing. Hands-on examples will be used to show how to evaluate and express the uncertainty of typical measurements encountered in optics manufacturing. We discuss common misunderstandings of measurement traceability and outline different routes that optics fabricators and metrologists may take to provide objective evidence that their measurement results are traceable. The course concludes with a discussion on the role of measurement uncertainty in conformity  assessment of products and the associated balancing of risk between trading partners.
 
Benefits and Learning Objectives
The course will enable participants to
  • Describe the concepts of the International System of Units (SI), measurement uncertainty, measurement assurance, and measurement traceability.
  • Explain the essential elements of metrological traceability and identify different approaches to achieve traceable measurements in the optics industry.
  • Apply the Guide to the expression of Uncertainty in Measurements (GUM) to evaluate and state the uncertainty of common measurements in optics manufacturing.
  • Describe the role of measurement uncertainty in conformity assessment.
  • Explain practical aspects of measurement assurance and its role in demonstrating measurement traceability.
  • Identify requirements and options for demonstrating competence of testing and calibration laboratories (ISO/IEC 17025).
  • Decide on a route to achieve traceable measurements, which suit the needs of their organization.
Intended Audience
This course is intended for practitioners: fabricators of optical components and metrologists who are increasingly urged by their customers to provide uncertainty statements and evidence of traceable measurements for their products. It is intended for quality managers planning to establish or improve a quality system for their company or who are considering laboratory accreditation. Finally, the course is also intended for anyone wishing to understand how the modern international metrology system applies to the optics industry.
 
Instructor Biographies
Ulf Griesmann is a physicist with the National Institute of Standards and Technology (NIST). He received his Dr. rer. nat. from the University in Bonn, Germany. At NIST Dr. Griesmann worked on precision spectrometry and properties of optical materials. His current research focus is form metrology of precision surfaces, methods for absolute metrology, and metrology of aspheric and free-form surfaces using nano-structured optics. Dr. Griesmann carries out calibration measurements of flatness and sphericity at NIST.

Johannes A. Soons is a mechanical engineer at the National Institute of Standards and Technology (NIST). He received his Ph.D. from the Eindhoven University of Technology in the Netherlands. Since 1994, Dr. Soons has conducted research at NIST on precision machining, documentary standards for machine tool metrology, form metrology of optical surfaces, surface texture metrology, and the role of measurement uncertainty in fabrication and testing.


SC417 Evaluating Aspheres for Manufacturability

Paul Dumas, QED Technologies, Inc., USA
Sunday, 22 June, 17:00 -20:00

Course Level
Advanced Beginner
 
Course Description
This course provides an overview of how aspheric surfaces are designed, manufactured, and measured. The primary goal of this course is to teach how to determine whether a particular aspheric surface design will be difficult to make and/or test. This will facilitate cost/performance trade off discussions between designers, fabricators, and metrologists.

We will begin with a discussion of what an asphere is and how they benefit optical designs. Next we will explain various asphere geometry characteristics, especially how to evaluate local curvature plots. We will also review flaws of the standard polynomial representation, and how the Forbes polynomials can simplify asphere analysis. Then we will discuss how various specifications (such as figure error and local slope) can influence the difficulty of manufacturing an asphere. Optical assembly tolerances, however, are beyond the scope of this course - we will focus on individual elements (lenses / mirrors).

The latter half of the course will focus on the more common technologies used to generate, polish, and/or measure aspheric surfaces (e.g. diamond turning, glass molding, pad polishing, interferometry). We'll give an overview of a few generic manufacturing processes (e.g. generate-polish-measure). Then we'll review the main strengths and weaknesses of each technology in the context of cost-effective asphere manufacturing.
 
Benefits and Learning Objectives
This course will enable you to:

  • Identify the most important metrics of aspheric shape that relate to manufacturability
  • Evaluate key characteristics of an aspheric surface to determine whether an asphere will be difficult to manufacture and/or test
  • Describe how Forbes polynomials can simplify asphere interpretation
  • Interpret an aspheric prescription from an optical component print
  • List common ways aspheres are manufactured and tested
  • Answer the question "Which technologies are best suited to manufacture this asphere?"
Intended Audience
This material is intended for engineers, optical designers, and managers who want an overview of the benefits and challenges associated with manufacturing aspheric surfaces for use in optical systems. It will be of benefit for specialists in a particular area (e.g. design, manufacturing, or testing), as it will give a broad overview in all three of those areas with a focus on aspheric surfaces. It is intended to facilitate communication between designers, fabricators, and testers of aspheric surfaces.
 
Instructor Biography
Paul Dumas is one of the founding members of QED Technologies, where he has developed software and processes for aspheric optical manufacturing.  He received his B.S. and M.S. in Optics from The Institute of Optics at the University of Rochester. In the early 1990s, and since has managed various engineering groups throughout the company's history, including Software, Systems, and Applications.

SC418 Optical Materials, Fabrication and the Testing for the Optical Engineer

Jessica Nelson, Optimax SI, USA
Sunday, 22 June, 09:00-12:00

This course is designed to give the optical engineer or lens designer an introduction to the technologies and techniques of optical materials, fabrication and testing.  This knowledge will help the optical engineer understand which optical specifications/tolerances lead to more cost effective optical components. Topics covered include optical materials, traditional, CNC and novel optical fabrication technologies, surface testing and fabrication tolerances. 

Course Level
Introductory

Benefits and Learning Objectives

This course will enable you to:

  • Identify key mechanical, chemical and thermal properties of optical materials (glass, crystals and ceramics) and how they affect the optical system performance and cost of optical components
  • Understand the basics of optical fabrication
  • Define meaningful surface tolerances
  • Communicate with optical fabricators
  • Design optical components that are able to be manufactured and measured using state of the art optical fabrication technologies
Intended Audience
Optical engineers, lens designers, or managers who wish to learn more about how optical materials, fabrication and testing affect the optical designer. Undergraduate training in engineering or science is assumed.
 
Biography
Jessica DeGroote Nelson is the R&D manager and scientist at Optimax Systems, Inc.  She specializes in optical materials and fabrication processes.  She is an adjunct faculty member at The Institute of Optics at the University of Rochester teaching an undergraduate course on Optical Fabrication and Testing, and has given several guest lectures on optical metrology methods.  She earned a Ph.D. in Optics at The Institute of Optics at the Universityand SPIE.