title: Accuracy of a multiple height-transfer interferometric technique for absolute distance metrology.
abstract: A multiple height-transfer interferometric technique was developed to increase the absolute distance measurement capability of a metrology system that uses a tunable laser. Using multiple accurately calibrated reference heights, this technique relaxes the requirement of knowing accurate wavelength information for multiple wavelength interferometry while maintaining its advantages. We present an uncertainty analysis, analyze the primary sources of uncertainties limiting the performance of this technique, and discuss how errors can be minimized. Measurement results of 3D images obtained from a variety of objects are presented. The measurement uncertainty is experimentally demonstrated to be 0.3 μm over 50 mm for two discontinuous surfaces with a confidence level of 95% in a lab environment.
authors.affiliation: Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48105, USA. haoyu@umich.edu
authors.forename: Hao
authors.initials: H
authors.lastname: Yu
authors.forename: Carl
authors.initials: C
authors.lastname: Aleksoff
authors.forename: Jun
authors.initials: J
authors.lastname: Ni