Optical Metrology of Aspheric and Freeform Mirrors

The NASA Science Missions Directorate seeks technology for cost-effective high-performance advanced space telescopes for astrophysics and Earth science applications. These applications require instruments with large aperture light-weight highly reflecting mirrors and precision optical surfaces to gain a better understanding of how the universe works. The hard and soft X-ray mirrors have stringent surface requirements. If awarded a Phase I our plan would be to combine previous knowledge of OptiPro's UltraSurf metrology system with newly developed software. Our goal would be to create a robust solution for combining the measurement data of the mirrors with corrective machine grinding and polishing process toolpaths. This proposal includes the investigation utilizing non-contact probes on OptiPro's machining platforms to quantify the potential opportunities for in-situ mirror measurements. Understanding these surface irregularities and what in the manufacturing processes causes them is critical for improving the current TRL's. OptiPro Systems will develop a metrology system and software, that would provide feedback for manufacturing these precision mirrors and include final metrology measurement of global form error and mid-spatial content. Comparison of in-situ and off-line metrology will be key for improving the manufacturing processes. We envision that the work performed in Phase I would lead to a software and metrology solution to be built and delivered to NASA if awarded a Phase II. OptiPro's technologically advanced optical manufacturing capabilities along with our support partnership with the University of Rochester Mechanical Engineering Department, gives us a very strong team and a clear path towards solving the difficult challenges for measuring these large complex mirrors and cylindrical shells. Our goal is to provide an innovative and complete manufacturing solution for the companies that are fabricating these optical components for NASA.