Accurate calibration of geometrical error in reflective surface testing based on reverse Hartmann test

The deflectometry provides a powerful metrological technique enabling the high-precision testing of reflective surfaces with high dynamic range, such as aspheric and freeform surfaces. In the fringe-illumination deflectometry based on reverse-Hartmann-test configuration, the calibration of system geometry is required to achieve "null" testing. However, the system miscalibration can introduce a significant systematic error in the testing results. A general double-step calibration method, which is based on the low-order Zernike aberration optimization and high-order aberration separation, is proposed to separate and eliminate the geometrical error due to system miscalibration. Both the numerical simulation and experiments have been performed to validate the feasibility of the proposed calibration method. The proposed method provides a general way for the accurate calibration of system geometrical error, avoids the over-correction and is feasible for the testing of various complex freeform surfaces. (c) 2018 Optical Society of America under the terms of the OSA Open Access Publishing AgreementZhejiang Provincial Natural Science Foundation of China [LY17E050014]; National Natural Science Foundation of China (NSFC) [51775528]; Project of General Administration of Quality Supervision, Inspection & Quarantine of China (AQSIQ) [2017QK033]; Guangxi Universities Key Lab of Optoelectronic Information Processing [KFJJ2017-02]Open access journal.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu