All-phase wavelength tunable interferometric synchronous measurement of multiple information for transparent planar optical elements

The traditional phase demodulation algorithm based on time-domain Fourier transform will cause phase demodulation errors due to spectral leakage caused by non-integer period truncation, thereby reducing the measurement accuracy. Therefore, a full-phase wavelength-shifting interferometry multi-information synchronous measurement method is proposed. By synthesizing a new interferogram through full-phase spectral analysis, the influence of spectral leakage on phase demodulation accuracy is suppressed to improve the measurement accuracy of the surface profile and thickness variation of optical components. In repetitive experiments, the thickness variation, the peak-to-valley (PV) difference and the root mean square (RMS) difference of the front and back surface profiles of a transparent optical plate with a thickness of 5 mm and a diameter of 150 mm were compared. The results showed that the relative standard deviation (RSD) of each index was less than 0.08, verifying the performance of the proposed method in the synchronous measurement of multiple information such as surface profile and thickness of transparent planar optical elements.