Freeform optical lenses and conformal windows enable new concepts for optical system designs and allow fewer elements to be used, making the systems smaller, lighter, and more efficient. Based on their special surface shape, freeform optics can provide functions that cannot be achieved with traditional optics and can replace large component designs utilizing mirror systems. Manufacturing a freeform optic is similar to manufacturing an off-axis asphere, as surface form and local slope change are all factors that influence the complexity of the manufacturing process. A freeform or conformal surface does not have any translational or rotational symmetry, which challenges traditional manufacturing techniques.
Freeform optics manufacturing begins with the definition of the surface as a refractive element, a reflective mirror, or a conformal window. In addition to a clear description of the optic, an equation, point cloud, or 3D model is required for production. Consideration must be given to the blank material, the equipment available, and the implementation of a robust process to efficiently produce the freeform workpiece or conformal window to the specified requirements. The surface irregularity, finish, and alignment requirements must be incorporated in the manufacturing phase to yield a workpiece that performs as designed. State-of-the-art manufacturing and measuring equipment with the proper tools, fixtures, and software is critical to the deterministic production of freeform optics.
***Recording produced in collaboration with Photonics Media.
About the presenter:
David Mohring is the metrology coordinator at OptiPro Systems. He has over 30 years of experience in CNC (computer numerical control) machine and optical fabrication development for the precision optics industry. He holds a bachelor’s degree in mechanical engineering from the Rochester Institute of Technology.
Mohring has designed precision automated manufacturing systems, and he supports the development of advanced fabrication and inspection techniques, including OptiPro’s advanced optical polishing platform, the UltraForm Finishing (UFF) system. In addition, Mohring designed and implemented multiaxis metrology systems such as contact and noncontact profilometers and coordinate measurement machines.
He teaches the advanced optical fabrication course for Monroe Community College and provides on-site customer training. He is a board member of the American Precision Optics Manufacturing Association (APOMA) and a certified Zeiss Calypso Multisensor CMM trainer. He has written winning SBIR proposals for NASA and NAVAIR (Naval Air) projects to advance the technologies required for precision manufacturing of brittle materials.