中文摘要：

提出了一种以再现参考光的峰值信噪比为判断条件的获取实际相移量的两步相移数字全息迭代方法。分析了再现参考光波的峰值信噪比与相移误差的关系。通过峰值信噪比的1阶、2阶导数来判断迭代方向及峰值信噪比是否达到最大，从而优化迭代过程、降低相移误差，并采用光学实验验证了该方法的可行性。

英文摘要：

An iterative method to extract actual phase shift in two-step phase-shifting digital holography is proposed, in which peak signal-to-noise ratio （PSNR） of the reconstructed reference wave is taken as a judging condition. The relationship between PSNR of the reconstructed reference wave and phase shift error is investigated. According to the 1st and 2nd order derivative of PSNR, the iterative direction and whether PSNR undergoes a maximum can be determined. Optical experiment is performed to demonstrate its validity.