Laser Fabrication with Integrated Metrology for Low-Cost Free-Form Optics

Free-form optics can improve sensors and instruments by enabling compact designs with fewer parts and enhanced performance.nbsp; 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.nbsp;nbsp;nbsp;nbsp;nbsp;nbsp;nbsp;nbsp;nbsp;nbsp;nbsp; However, free-form optics manufacturing is expensive and requires lengthy production time hindering the adoption of this new design paradigm.nbsp; A significant problem with modern optics machining is the use of open-loop control which leaves the desired ultra-precise surfaces susceptible to malformation via non-deterministic effects.nbsp; 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.nbsp;nbsp;nbsp;nbsp;nbsp;nbsp;nbsp;nbsp;nbsp;nbsp;nbsp;nbsp; 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 (gt;1mm), small inflection points, and asymmetries.nbsp; The approach of measuring optical properties, in contrast to the ndash; as usual ndash; physical shape, will also ensure the parts are functionally deployable. The overall project outcome will be a freeform 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.nbsp;