Non-contact metrology of datum surfaces and fiducials on freeform telescope mirrors

Freeform optical surfaces are becoming an important tool for improving the size, cost, and performance of optical systems. Accurate and efficient metrology tools are a core component of the manufacturing chain for freeform surfaces. Due to the unique capabilities of freeform optical surfaces, the metrology system must be able to measure both the active optical area and features that control the alignment of the freeform surface within the overall optical system. The Center for Freeform Optics fabricated a freeform metrology-artifact mirror. We will demonstrate the metrology of both the optical surface and datum surfaces for a freeform optical mirror using the QuickPRO-3D metrology tool. The figure error of the optical surface will be evaluated with respect to different coordinate systems that exist on the part.