The broader/commercial impact of this Small Business Innovation Research Phase I project is to advance high-accuracy, rapid, on?shop floor or in?machine dimensional measurements of precision machined parts. These measurements are conducted with Coordinate Measuring Machines (CMM), representing a $4 B market. The proposed project will develop a new portable CMM instrument for precision machine shops, bottlenecked by their high?cost stationary CMMs or limited by low-accuracy portable CMMs. In?machine part inspection will reduce waste for one?off or prototyping shops. It will further improve CNC machining process control of large batch jobs by allowing rapid statistical sampling of the accuracy of CNC-machined parts mid?process. The new technology will improve efficiency and accuracy in machine shops, lowering the cost of manufactured parts. The intellectual merit of this project is to surmount two primary technical hurdles needed to complete a working prototype of the new interferometer?based Coordinate Measuring Machine (CMM). These hurdles include the development of an absolute distance interferometer measurement system, tuned specifically for the novel CMM, and the development of the custom mechanical, optical, and data acquisition/processing systems required for its function. The new interferometer?based CMM will have multiple inherent advantages over existing portable CMMs, including sensitivity, absolute accuracy (tied directly to the wavelength of light) and long?term reliability. The novel approach addresses many challenges in the 3D metrology domain. Research tasks include diode laser frequency locking with high absolute accuracy, merging of multiple absolute distance interferometry methods, construction and optimization of the mechanical and optical systems, and integration of software and hardware.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.