标题：Lensless phase-shifting point diffraction interferometer for spherical mirror measurement
作者：Yang, Zhongming; Dou, Jiantai; Yuan, Qun; Gao, Zhishan
作者机构：[Yang, Zhongming] Shandong Univ, Sch Informat Sci & Engn, Jinan 250100, Shandong, Peoples R China.; [Yang, Zhongming] Shandong Univ, Shandong Prov K 更多
通讯作者地址：[Yang, ZM]Shandong Univ, Sch Informat Sci & Engn, Jinan 250100, Shandong, Peoples R China;[Yang, ZM]Shandong Univ, Shandong Prov Key Lab Laser Technol 更多
来源：OPTICS AND LASERS IN ENGINEERING
关键词：Diffraction; Interferometry; Spherical surface; Metrology
摘要：We demonstrate a lensless phase-shifting point diffraction interferometer with a tiny pinhole to measure spherical mirror surface figures. The interferograms used to reconstruct the surface figure are formed without imaging optics. Fresnel diffraction calculations with a coordinate transformation are studied as a means of reconstruction method for wavefront amplitude and phase. The Radon transform is used to determine the distance from the tiny pinhole to the CCD target, which guarantees the accuracy of the diffraction calculations. Our lensless phase-shifting point diffraction interferometer not only retains the higher measurement precision by the ideal reference wavefront, but also overcome the fabrication and mounting limitation of the imaging optics. The simulations and experiments have validated the accuracy and feasibility of the spherical mirror measurement by proposed lensless phase-shifting point diffraction interferometer. (C) 2018 Elsevier Ltd. All rights reserved.