In Phase I, we have begun development of an advanced nanometer coordinate measuring machine (ANCMM; pronounced ’aŋ-kem) to complement the metrology probe and complete the metrology solution. The ANCMM will enable larger, lower cost, and higher quality freeform and aspheric optics, bridging the present gap between commercial coordinate measuring machines (CMMs) and interferometry, and, for many applications, replacing areal interferometry as the primary means of feedback to optical fabrication and requirements verification. This work will push CMM technology into the realm currently dominated by expensive, complex, and error-prone optical testing. Current and near-future, large optics applications would benefit from the ANCMM by reducing their fabrication cost and schedule and improving their technical risk posture. Current optical metrology techniques struggle to meet requirements and are rife with potential for systematic error. For many manufacturers, the expense of optical testing often precludes the types of cross checks that are important to protecting their products from systematic error. Cross checks that show that presumed superior, unverifiable, optical tests that have uncertainties which overlap higher-uncertainty, flexible, metrology can identify “gross errors”. Large, meter-class optics with figure error tolerances better than or of-order 10 nm RMS are required for current and near-future telescopes for astrophysics. The ANCMM platform concept proposed herein will incorporate new laser measurement components and strategies with the metrology loop separate from the motion control feedback loop. This concept will also incorporate a tactile and non-contact probe sensor system for datum and surface form metrology.
Primary and secondary concept mirror designs for the LUVOIR, OST and Lynx x-ray mirror assembly and off axis parabolics have been reviewed and we have developed the requirements for a next level metrology platform. The current reliance on standard interferometric measurement methods limits the geometric concept design of mirrors in new missions. Freeform surface metrology is fundamental for the success of future NASA missions in Astrophysics, Earth Science, Planetary Science and Cubesat platforms including the SAFE Minispec instrument.
OptiPro Systems provides state of the art manufacturing and measurement solutions for prime contractors and a host of precision optics manufacturers. The proposed ANCMM platform will provide a method to measure freeform optics, parabolic mirrors, Acylinder and toric geometries to lower uncertainty than currently available.