Development of error estimation method for phase detection in phase shift method

摘要

In this report, error estimation method of phase detection in phase shift method is proposed. Phase detection algorithm extracts phase of modulated signal from several numbers of interferogram that acquired during phase shifting. The fourier domain expression of phase detection algorithms show frequency response for sine and cosine components. And it shows behavior for phase detection in the case that phase shifting error exists. However, these two response functions, those are response function for sine component and that for cosine component, do not directly show frequency response of phase detection itself. On the contrary, newly developed frequency response function, which is derived from these two frequency response function, directly shows frequency response of phase detection. And it clearly shows the behavior of phase detection algorithm when phase tuning error exists. The newly developed frequency response function is similar to the Bode plot. The magnitude plot shows sensitivity for frequency components. And the phase plot can be used for error estimation of phase detection. There is good agreement between the developed frequency response function and calculated error value. These results of comparison between error estimation using developed frequency response function and calculated error value are shown in this report.