Precision Optics Manufacture and Metrology

Abstract

Precision optical surfaces are amongst the most accurate surfaces made by man. The journey of a “lump“ of glass from foundry to a finished optic requires processes that can finesse the optical surface by over six orders of magnitude. At each stage, dimensional and other metrology is required for verification. Final verification of the optical surface requires methods and instrumentation that are sensitive to surface variations similar in size to one hydrogen atom. The adage, “if you cannot measure it then you cannot make it” is a truth that lies at the heart of the manufacture of optical surfaces.

In this talk we will review how a “large” precision optic is made and will discuss the verification needed at each stage of manufacture. Taking examples from science and aerospace, we will investigate how factors such as optical surface shape and size affect the metrology required and its implementation. The talk will conclude with a look at some trends in the manufacture of precision optics and the likely demands they will make of metrology.

Seminar Recording

Biography

Paul Rees is Professor of Optics: Metrology and Technology at Glyndŵr University. He is a lead systems engineer and project scientist with over twenty years’ experience in astronomical telescope design, the commissioning of instrumentation and the manufacture of large optics. He has led the metrology of large optics programme at Glyndwr University’s St Asaph Campus since 2008. He is also active in the design and manufacture of optical systems for aerospace applications.

Prior to joining Glyndwr University, Paul led the Final Acceptance programmes for the Yunnan 2.4m telescope, China, and the IUCAA 2.0m telescope, India, for Telescope Technologies Ltd, and delivered a succession of complex multi-disciplinary engineering projects for the company.

He holds a PhD in Astronomy from University College London and has been a Fellow of the Royal Astronomical Society since 1984.