Freeform and conformal optical manufacturing

Abstract

Future optical systems are moving away from traditional spherical optics. The anticipated benefits are numerous for freeform optics as they provide better aerodynamic characteristics for aircraft, lighter weight for space missions, and smaller size for medical procedures. Currently the design and utilization of conformal and freeform shapes are costly due to the difficulties introduced with fabrication and metrology of these parts. Techniques for creating these complex optical surfaces are still in development for traditional optical materials. OptiPro has a unique opportunity create manufacturing solutions through computer controlled multi-axis optical generating, polishing, and metrology machines. OptiPro Systems is continuing to develop advanced optical manufacturing technologies. OptiPro has made toric and freeform arch shapes. OptiPro’s existing manufacturing platforms include its eSX grinding, UltraForm Finishing, and UltraSurf non-contact surface scanning system, which will be used for grinding, polishing, and measuring conformal and freeform shapes. Freeform surfaces are initially generated using deterministic micro-grinding with diamond bonded tools. Tool paths with up to five axes of simultaneous motion are required to generate and polish the optical figure of conformal surfaces. Sub-aperture corrective polishing will need to vary the amount of time the tool contacts at each location in order to remove the proper amount of material. These locations and dwell times are derived from a surface figure error map provided by OptiPro’s UltraSurf. Research and development of the freeform manufacturing process will be presented.