Error analysis of laser interferometric system for measuring radius of curvature

Abstract Spherical surfaces are essential components of optical systems and imaging devices. Moreover, precision spheres calibration standards for many accurate instruments in dimensional mass metrology. A spherical surface's main property is its radius curvature, which can be measured using contact or non-contact methods. Interferometry an technique, but some error sources impact it. This study investigates seventeen that affect a laser interferometric system measuring the curvature sphere. The measurements obtained Fizeau interferometer (GPI-XP, Zygo) with phase-shifting capability displacement (ZMI-1000, Zygo). silicon–nitride sphere nominal 12.49965 mm dealt this study. One contributions proposing three additional sources: focal shift, distortion, y -axis vibration. Besides, deadpath, nulling, shift contributed 70% total uncertainty budget. Also, to correlate measurement accuracy reference surface, transmission ( f /3.3, /1.5, /0.65) employed; /0.65 reported most 12.49922 ± 0.00089 mm. also dependence nulling on coverage factor defines tested surface area. analysis optimum conditions minimize system's potential described work.