Determination of Measurement Uncertainty and Calibration of the Developed Instantaneous Phase Shifting Interferometer
In this paper, detection of system noise in the optical layout for instantaneous phase shifting interferometry is discussed. Experiments were carried out on various surfaces using the developed interferometer to determine the repeatability of the system. The results were then compared with the results from a commercial profiler to ascertain the uncertainty in the developed system and to calibrate the developed system. The uncertainties identified in the system were attributed to the larger measurement area, compared to that of the commercial profiler and the use of non-standard reference surfaces for measurement. The system was found to be less sensitive compared to that of the WYKO NT 2000 white light profiler.