Technical Abstract (Limit 2000 characters, approximately 200 words):
Free-form optics can improve sensors and instruments by enabling compact designs with fewer parts and enhanced performance. As such, they are poised to impact many NASA missions from remote sensing and communications using small satellite constellations to future x-ray observatories like Lynx and AXIS to coronagraphs within HabEx and LUVOIR.
However, free-form optics manufacturing is expensive and requires lengthy production time hindering the adoption of this new design paradigm. A significant problem with modern optics manufacturing tools is the use of open-loop control which leaves the desired ultra-precise surfaces susceptible to malformation due to non-deterministic effects. It is only through multiple iterations of machining and in-process metrology that is possible to reach nanometer precision. These manufacturing challenges are exacerbated by free-form optical designs that rely on difficult multi-axis sub-aperture machining or tool rastering and protracted 3-D surface characterization techniques.
The technical objectives in this project open the opportunity for low-cost, free-form optics manufacturing by integrating an in-situ optical metrology system into a newly-developed laser-based machining tool to achieve nanometer (x, y, z) root mean square precision over a 160 cm^2 glass workpiece. The metrology system will overcome the current challenges of characterizing free-forms with large spherical departure (>1mm), small inflection points, and asymmetries. The approach of measuring optical properties, in contrast to the – as usual – physical shape, will also ensure the parts are functionally deployable. The overall project outcome will be an optics manufacturing technology akin to the significance of CNC machining ushering in a new generation of rapid, cost-effective, and high-precision manufacturing that will be transformative to the optics industry.