Suppression of random intensity error for the measurement of surface shape by using a novel phase shifting algorithm

In this paper, the method for evaluating the susceptibility of phase shifting algorithms to random intensity error is developed. In order to suppress the random intensity error, the 9N 8 algorithm comprising a new polynomial window function and a DFT is derived by using the theory of characteristic polynomial. The susceptibility of random intensity error and the root sum square error of 9N 8 algorithm is discussed and compared with several conventional algorithms. Finally, the 9N 8 algorithm was applied for the measurement of surface shape using a wavelength tuning Fizeau interferometer. The experiment results indicated that proposed algorithm is insensitive to random intensity error and the measurement accuracy is 2.401nm. CCS CONCEPTS • Computing methodologies; • Modeling and simulation; • Model development and analysis; • Model verification and validation;