In phase-shifting interferometry, a phase shifter usually has tilt shift error along with translational shift error during shifting. The pixels on the same interferogram can not be shifted by an equal amount. Thus the phase measurement errors can not be avoided, even when the translational shift error has been corrected effectively. However, based on the fact that phase shifts of all the pixels on the same interferogram are still kept on the phase shift plane. So by solving this plane the phase errors can be eliminated significantly. In this paper, a new algorithm insensitive to both the translational and tilt shift errors of a phase shifter for phase-stepping interferometers is presented. The first order Taylor series expansion replaces the nonlinear equations in solving the phase shift plane, and by iterative, the accuracy can be guarantied. The simulative and experimental results show that phase measurement errors caused by both translation and tilt shift-error can be compensated significantly.
展开▼
