Title: Some Milestones In The Design, Development And Manufacture Of Freeform Optics
Freeform optics are lenses or mirrors with surfaces having no rotational symmetry. They were conceived more than a century ago, but have recently received new attention for solving design problems. The special methods needed to manufacture them have included direct cam driven or digital grinding or milling, hot glass sagging, casting, injection molding, and fast-tool diamond turning. More recently, precision 3D printing and nano-crystalline powder compression molding have offered promising new capabilities for inexpensive high-volume commercial production in the future. Applications of freeform optics have included progressive spectacle lenses, focus adjusting devices, and aperture phase masks for special purposes. These design applications and manufacturing capabilities have been related to each other in interesting ways, and will be illustrated through a selection of patents and photographs of commercial products.
Key Words: Freeform, molding, spectacles, infrared, 3D printing
William Plummer received his PhD in physics from Johns Hopkins. He has taught optics at Hopkins, the University of Massachusetts, and Tufts, is a Senior Lecturer at MIT, and has 102 US patents. During three decades at Polaroid he was Senior Director for optical engineering.He has awards from the OSA, is an elected member of the National Academy of Engineering, and is an Advisory Board member at BMF Material Technology, Shenzhen.