Grinding & Polishing of meter class off-axis aspheric optics

The grinding and polishing of off-axis aspheres is particularly challenging as an axis of symmetry on the desired optical surface does not exist with which to take advantage. The tool incorporated 18 servo motors and load cells to provide closed loop force control to deform a 2 thick aluminum shell to accommodate the change in surface figure as the tool was moved across the optic by three additional servo motor controlled linear actuators. Additionally a pneumatic cylinder provided vertical load control for use on lightweight optics.