Advanced Nanometer Coordinate Measuring Machine

In Phase I, we have begun development of an advanced nanometer coordinate measuring machine (ANCMM; pronounced rsquo;a?-kem) to complement the metrology probe and complete the metrology solution.nbsp; 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.nbsp; This work will push CMM technology into the realm currently dominated by expensive, complex, and error-prone optical testing. nbsp;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.nbsp; Current optical metrology techniques struggle to meet requirements and are rife with potential for systematic error.nbsp; 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.nbsp; Cross checks that show that presumed superior, unverifiable, optical tests that have uncertainties which overlap higher-uncertainty, flexible, metrology can identify ldquo;gross errorsrdquo;.nbsp; 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.nbsp; 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. nbsp; This concept will also incorporate a tactile and non-contact probe sensor system for datum and surface form metrology.nbsp;