Advanced Nanometer Coordinate Measuring Machine

In this work, we propose the development of an Advanced Nanometer Coordinate Measuring Machine (ANCMM; pronounced rsquo;aŋ-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;ANCMM will have the capability to measure the prescription and mid- and low-order surface error for meter-class segments for large astronomical telescopes.nbsp; Accurate metrology of the prescription (i.e., radius of curvature, conic constant, and off-axis distances) will speed the fabrication, hence reducing costs, of primary mirror segments, because ANCMM metrology will have greater dynamic range than current CMM technology, allowing ANCMM to be used ldquo;deeperrdquo; into the fabrication process (i.e., from rough machining and grinding of blanks though the fine stages of optical polishing) before transitioning to an interferometric test, if that is even required for the final stages of polishing and verification.nbsp;nbsp;Both cylindrical mirrors and freeform surfaces require stringent surface requirements and plan to be implemented in future NASA missions like LISA and LUVOIR.nbsp;nbsp; OptiPro Systems and the UNC Charlotte Center for Precision Metrology have built and tested contact and non-contact multi axis measurement platforms and will be utilized during this project.nbsp; Theoretical and laboratory experimental data analysis of prospective instruments and measurement techniques will guide the development of the design constraints and provide valuable data to verify the ANCMM system uncertainty budget.