Diamond Machining of Freeform Optics – Dr. Matt Davies, University of North Carolina at Charlotte

Freeform optics are a revolutionary technology in the optics industry moving away from the centuries-old design principals based on optics with an axis of symmetry either on or off the optic.  Freeform shapes allow a nearly arbitrary redirection of light in three-dimensions which has many advantages including miniaturized and lower mass systems, improved performance and in some cases entirely new optical functionality.  However, the manufacturing and metrology of freeform optics remains a major challenge for the industry.  Multi-axis diamond machining including coordinated-axis diamond turning, diamond milling and precision grinding are a viable technology for freeform optics production.  This tutorial is for industry, laboratory and academic scientists and engineers who have some knowledge of conventional manufacturing and basic diamond turning.   It will cover: (1) generation of freeform surfaces by diamond machining; (2) programing and error correction techniques for multi-axis freeform diamond machining; (3) development and choice of parameters for freeform diamond machining of different materials for both reflective and transmissive applications, and (4) on-machine metrology methods.  Numerous examples of freeform optics and optical systems will be discussed including a miniature imaging spectrometer, freeform three-mirror anastigmat (TMA) systems, glass molding and numerous infrared optics.  The tutorial does not cover machining with tools that do not have a defined cutting edge such as grinding and polishing.   At the end of the tutorial successful participant will have learned the following.

  • To identify the different configurations needed to diamond machine freeform surfaces and the pros and cons of each
  • To identify which materials can be freeform diamond machined and which cannot and have a knowledge of the cutting mechanics in these materials
  • Understand how to set up a turning or milling tool for freeform machining and minimize the tool setting errors
  • Understand the methods for programming ultraprecision machines to do freeform diamond machining
  • Understand the basic concepts in the opto-mechanical design of freeform systems and how this differs from conventional optical systems
  • Be familiar with different methods of on-machine metrology for freeform optics

Diamond Machining of Freeform Optics – Dr. Matt Davies, University of North Carolina at Charlotte

Dr. Matt Davies earned a Ph.D in Aerospace Engineering from Cornell University (1993) and then joined the Manufacturing Engineering Laboratory at NIST.   He then came to the University of North Carolina at Charlotte, Center for Precision Metrology, in the spring of 2002. Dr. Davies’ research focuses on the study of applied engineering systems and the development of practical applied manufacturing and metrology solutions based on the research.  In particular, his work at NIST work was applied to the stability of high-speed machining processes and on the study of the complex plastic flows of material that occur in the vicinity of the tool in machining processes.  He has continued this research at Charlotte where his group developed a high-bandwidth thermal imaging system that produced the highest resolution thermal images of chip formation available at the time.  After coming to Charlotte, Dr. Davies pursued two new research areas, metrology and mechanics for the biomedical device industry and the ultraprecision machining of complex optics.  He published several papers on the biomechanics of implants including the first papers on the mechanics of implants for the cervical spine with articulating (ball) joints and papers on the deformation of the acetabular cup in hip implants and its implications for implant wear.   He then started a research group focused on the manufacture of freeform and structured optics and is the leader of the Freeform Optics Research Group. 

Dr. Davies was the Director for the Center for Freeform Optics ( a collaborative consortium with the University of Rochester between 2015 and 2019 and during that time he helped build the Center membership to 18 non-academic members.  Dr. Davies has received numerous honors and awards and has more than 75 technical publications and three patents.   He is a Fellow of the Fannie and John Hertz Foundation, was awarded the United States Department of Commerce Bronze Medal in 1998, the Society of Manufacturing Engineering, John T. Parsons, Outstanding Young Manufacturing Engineer Award in 2000, the Bonnie Cone Professor for Excellence in Teaching in 2007, the Bank of America Award for Teaching Excellence in 2016 and the North Carolina Board of Governors Teaching Award in 2017.  He is currently also conducting research in Adaptive Learning for the teaching of Engineering System Dynamics and has been a Fellow of the CIRP since 2009.   He has been a member of the American Society for Precision Engineering since 1994.