相移误差在很大程度上影响着相移数字显微全息的测量精度。相移误差可大致分为数值误差和不均匀误差两类。相移器的标定错误和环境震动都能产生不可忽略的数值误差,因此自定标相移数字全息是值得探究的。提出了一种基于载频条纹分析方法的自定标相移数字全息显微术。利用傅里叶条纹解调分析方法,分别提取四幅全息图的载频条纹相位。通过对比载频条纹相位获得全息图间的相移量。实验装置设计的不合理导致了不均匀误差。提出一种基于改进型Linik干涉仪的相移数字全息显微装置。实验结果证明了自定标算法和改进型的Linik干涉仪具有更好的重建结果。
Small phase shift errors in phase-shifting digital holographic microscopy can cause distinct errors in wave- front reconstruction. Phase shift errors generally fall into two categories., numerical errors and uneven errors. A considerable numerical error results from miscalibration of phase shifter and ambient vibrations, Therefore, self- calibration phase-shifting scheme is worth trying. Here, a carrier frequency analysis based self-calibration phase- shifting digital holographic microscopy (PSDHM) is proposed. The actual phase shifts are calculated from Fourier analysis of holograms. The uneven errors are caused by irrational configuration of interferometer. We propose an improved Linik interferometer based setup of phase-shifting digital holography. The experimental results certify that both the self-calibration phase-shifting scheme and the proposed experimental setup have a better reconstruction quality.