Decrease in the Error at Elimination of Phase Ambiguity by Method of Equivalent Wavelength

This article describes a method for reducing the phase error in a multifrequency method for eliminating phase ambiguity in digital, including holographic, measuring systems. The proposed method involves obtaining a series of interference patterns with different wavelengths and decoding them by the phase shift method. Reduction in error is ensured by combining the integer values of the phase obtained for an equivalent wavelength with the averaged values of the phase of the original wavelengths, which allows to eliminate the effect of accumulation of errors and, accordingly, to reduce the overall error in determining the phase. This allows us to extend the range of applicability of the method for eliminating phase ambiguity when several wavelengths are used. The method was tested by deciphering test patterns with a given noise level. The method showed stability to phase and amplitude noise.