The phenomenon of Talbot image formation on a stepped surface is described and demonstrated both theoretically and experimentally. The Talbot self-image shift on the surface step is observed and implemented for the measurement of the three-dimensional step height of a large discontinuous object with an optically plane surface. Due to the measurement of the phase not being required, the system is free from phase ambiguity problem. This means that the measurement range is larger as compared with the interferometric techniques. Based on the simulation analysis and experimental measurements, minimal and maximal measurable steps are calculated. (C) 2022 Society of Photo-Optical Instrumentation Engineers (SPIE)
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