White light phase-shifting interferometry with self-compensation of PZT scanning errors

One of main error sources in scanning white light interferometry is the inaccuracy of scanning mechanisms for which PZT piezoelectric ceramics actuators are widely used. In this paper, we propose a new calibration method being capable of identifying actual scanning errors directly by analyzing the spectral distribution of sampled interferograms. Experimental results prove that the method provides an effective means of in-situ self-calibration enhancing the measurement uncertainty by one order of magnitude.