Designing Optical Coatings, It Is All Done with Mirrors

Lenses typically reflect over 4% of the incident light from each uncoated surface. This causes not only loss of light to the image to be formed, but unwanted stray light which may get to the image. This problem will be illustrated with simple eyeglasses and their need for antireflection (AR) coatings. The underlying principles of optical thin film coatings will be briefly discussed and illustrated by viewing their behavior on reflectance amplitude diagrams.

The related topics to be discussed include single layer and multilayer antireflection coatings, beamsplitters, long-wave-pass filters, short-wave-pass filters, narrow bandpass filters, and the problems with polarization. Some other factors to be shown are the limitations and possibilities of AR coatings, problems of too thick or too thin coatings, too many or too few layers, quantization of designs in overall thickness, and the tendency of design optimizations to get stuck in local minima.

About the presenter
Ron Willey, optical design and production trainer and consultant, has over 50 years of experience in optical system and optical coating development, design, and production, with special emphasis in the areas of practical thin-films design, process development, and the application of industrial DOE (design of experiments) methodology. He is the inventor of a robust plasma/ion source for optical coating applications.

Willey worked in optical instrument development and production at Perkin-Elmer, Block Associates, United Aircraft, Martin Marietta, Opto Mechanik, and Hughes, and formed Willey Corporation, which serves a wide variety of clients with consulting, development, prototypes, and production. He has a Bachelor of Science degree in optical instrumentation from the Massachusetts Institute of Technology and a Master of Science degree in computer science from the Florida Institute of Technology.

He has published many papers on optical coating design and production. His recent books are Practical Design of Optical Thin Films, 6th ed. (2022), and Practical Production of Optical Thin Films, 5th ed. (2017). His weeklong course is offered quarterly and is also available on DVD. He is a fellow of The Optical Society (OSA) and SPIE and a past director of the Society of Vacuum Coaters.