Plenary Event
Tuesday Plenary Session
9 April 2024 • 09:00 - 10:35 CEST | Auditorium Schweitzer, Niveau/Level 0
9:00 – 9:05 hrs CEST
Welcome and Opening Remarks
Speaker Introduction
9:05-9:50 hrs CEST
Lessons in lens design from Rudolf Kingslake: in the modern computing era can we learn anything new from the past?
Rudolf Kingslake is widely regarded as one of the founders of modern optical design. When educating his students at The Institute of Optics, Professor Kingslake championed the importance of lens design fundamentals as a complement to computer-aided design. At that time, ray tracing speed was a major bottleneck in the lens design process. Now that lens designers can trace rays in fractions of a second and have access to powerful computational tools like global optimization and AI are these same fundamentals needed? Should we keep teaching them? One of Kingslake’s biggest fears was that we would forget “our laboriously acquired knowledge of geometrical optics and substitute for it the mathematical problem of optimizing a merit function”.
There is no question that computers have done wonders for lens design and have enabled far more advanced designs than thought possible. The issue at hand is if mastery of both lens design fundamentals and computer software is required for success. Unfortunately, the current educational landscape places much more emphasis on the latter than the former, and many of the fundamentals impressed by Kingslake have been lost. However, three boxes of index cards belonging to Rudolf Kingslake were recently uncovered. Included in the collection are 171 lens design exam problems which present a fascinating perspective on lens design as it was taught in the pre-computer age. In this talk we’ll take a closer look at several of these forgotten problems and discuss how their solutions are still relevant for modern lens design today.
Julie Bentley is a Professor at The Institute of Optics, University of Rochester and has been teaching undergraduate and graduate level courses in geometrical optics, optical design, and product design for more than 25 years. She received her B.S., M.S., and PhD in Optics from The Institute of Optics. She is a Fellow of both SPIE and OSA, a former president of the Rochester Optical Society, and was recently elected into the presidential chain of SPIE. She has served as an SPIE board member, an associate editor for Optics Express, and the chair for the International Optical Design Conference (IODC) and SPIE’s optical fabrication conference (Optifab). She holds several U.S. patents and co-authored her first book, Field Guide to Lens Design, with S. Craig Olson (SPIE Press, 2012). Her expertise is in the optical design and tolerancing of precision optical assemblies. Prior to teaching full time, she managed a commercial technology team at Corning Tropel. She is also currently the president of an optical design consulting business, Bentley Optical Design, where she designs lens systems for a wide variety of applications, including medical devices, visible and infrared military optics, AR/VR systems, and other consumer optics.
9:50 - 10:35 hrs CEST:
Manufacturing ELT M1 segments: large optics in a smart factory
In 2017, the European Southern Observatory (ESO) awarded a contract for the Polishing, integration and final figuring of the Segment Assemblies of the primary mirror (M1) for the Extremely Large Telescope (ELT) to Safran Reosc. Since then, the design and commissioning of a production unit dedicated to ELT M1 has been accomplished and the plant has been producing many mirrors since spring 2022. We will introduce the smart factory, its processes and their automation that enabled reaching the current throughput of one mirror per day. We will then present the status of the project, some lessons learned and highlight the successes that have been achieved so far.
After a PhD in physics at the Ecole Normale Supérieur, Camille Frapolli joined Safran REOSC in 2017 as a metrology engineer. He worked on the development of several ELT test benches until 2020, when he became the chief engineer on ELT M1. Since 2023, he is also leading the optical design and new test benches development team at Safran REOSC.
Welcome and Opening Remarks
 |
Thierry Lépine
Institut d’Optique & Hubert Curien Lab (France) 2024 Symposium Chair |
Speaker Introduction
 |
Tina Kidger
Kidger Optics Associates (United Kingdom) 2024 Symposium Chair |
 |
Marta C. de la Fuente
ASE Optics Europe (Spain) 2024 Symposium Chair |
9:05-9:50 hrs CEST
Lessons in lens design from Rudolf Kingslake: in the modern computing era can we learn anything new from the past?
 |
Julie L. Bentley
The Institute of Optics, Univ. of Rochester (United States) |
Rudolf Kingslake is widely regarded as one of the founders of modern optical design. When educating his students at The Institute of Optics, Professor Kingslake championed the importance of lens design fundamentals as a complement to computer-aided design. At that time, ray tracing speed was a major bottleneck in the lens design process. Now that lens designers can trace rays in fractions of a second and have access to powerful computational tools like global optimization and AI are these same fundamentals needed? Should we keep teaching them? One of Kingslake’s biggest fears was that we would forget “our laboriously acquired knowledge of geometrical optics and substitute for it the mathematical problem of optimizing a merit function”.
There is no question that computers have done wonders for lens design and have enabled far more advanced designs than thought possible. The issue at hand is if mastery of both lens design fundamentals and computer software is required for success. Unfortunately, the current educational landscape places much more emphasis on the latter than the former, and many of the fundamentals impressed by Kingslake have been lost. However, three boxes of index cards belonging to Rudolf Kingslake were recently uncovered. Included in the collection are 171 lens design exam problems which present a fascinating perspective on lens design as it was taught in the pre-computer age. In this talk we’ll take a closer look at several of these forgotten problems and discuss how their solutions are still relevant for modern lens design today.
Julie Bentley is a Professor at The Institute of Optics, University of Rochester and has been teaching undergraduate and graduate level courses in geometrical optics, optical design, and product design for more than 25 years. She received her B.S., M.S., and PhD in Optics from The Institute of Optics. She is a Fellow of both SPIE and OSA, a former president of the Rochester Optical Society, and was recently elected into the presidential chain of SPIE. She has served as an SPIE board member, an associate editor for Optics Express, and the chair for the International Optical Design Conference (IODC) and SPIE’s optical fabrication conference (Optifab). She holds several U.S. patents and co-authored her first book, Field Guide to Lens Design, with S. Craig Olson (SPIE Press, 2012). Her expertise is in the optical design and tolerancing of precision optical assemblies. Prior to teaching full time, she managed a commercial technology team at Corning Tropel. She is also currently the president of an optical design consulting business, Bentley Optical Design, where she designs lens systems for a wide variety of applications, including medical devices, visible and infrared military optics, AR/VR systems, and other consumer optics.
9:50 - 10:35 hrs CEST:
Manufacturing ELT M1 segments: large optics in a smart factory
 |
Camille Frapolli
Safran Reosc (France) |
In 2017, the European Southern Observatory (ESO) awarded a contract for the Polishing, integration and final figuring of the Segment Assemblies of the primary mirror (M1) for the Extremely Large Telescope (ELT) to Safran Reosc. Since then, the design and commissioning of a production unit dedicated to ELT M1 has been accomplished and the plant has been producing many mirrors since spring 2022. We will introduce the smart factory, its processes and their automation that enabled reaching the current throughput of one mirror per day. We will then present the status of the project, some lessons learned and highlight the successes that have been achieved so far.
After a PhD in physics at the Ecole Normale Supérieur, Camille Frapolli joined Safran REOSC in 2017 as a metrology engineer. He worked on the development of several ELT test benches until 2020, when he became the chief engineer on ELT M1. Since 2023, he is also leading the optical design and new test benches development team at Safran REOSC.