Medina Orlando, Estrada Julio C, Servin M
Opt Express. 2013 Dec 2;21(24):29687-94. doi: 10.1364/OE.21.029687.
Optical interferometers are very sensitive when environment perturbations affect its optical path. The wavefront under test is not static at all. In this paper, it is proposed a novel and robust phase-shifting demodulation method. This method estimates the interferogram's phase-shifting locally, reducing detuning errors due to environment perturbations like vibrations and/or miscalibrations of the Phase-Shifting Interferometry setup. As we know, phase-shifting demodulation methods assume that the wavefront under test is static and there is a global phase-shifting for all pixels. The demodulation method presented here is based on local weighted least-squares, letting each pixel have its own phase-shifting. This is a different and better approach, considering that all previous works assume a global phase-shifting for all pixels of interferograms. Seeing this method like a black box, it receives an interferogram sequence of at least 3 interferograms and returns the modulating phase or wavefront under test. Here it is not necessary to know the phase shifts between the interferograms. It does not assume a global phase-shifting for the interferograms, is robust to the movements of the wavefront under test and tolerates miscalibrations of the optical setup.
当环境扰动影响光程时，光学干涉仪非常敏感。被测波前根本不是静态的。本文提出了一种新颖且稳健的相移解调方法。该方法在局部估计干涉图的相移，减少了由于振动和/或相移干涉测量装置校准错误等环境扰动引起的失谐误差。众所周知，相移解调方法假设被测波前是静态的，并且所有像素都有全局相移。这里提出的解调方法基于局部加权最小二乘法，使每个像素都有自己的相移。考虑到之前所有的工作都假设干涉图的所有像素有全局相移，这是一种不同且更好的方法。将此方法视为一个黑箱，它接收至少3幅干涉图的干涉图序列，并返回被测调制相位或波前。这里不需要知道干涉图之间的相移。它不假设干涉图有全局相移，对被测波前的移动具有鲁棒性，并且能容忍光学装置的校准错误。
