An effective approach to removing zero-order term overlap and controlling image distortion in digital off-axis holography

In this paper, we propose and describe a novel nonlinear numerical filtering approach to remove the zero-order term which overlaps the image, and meanwhile, to effectively control the image distortion in digital off-axis holography. To reach this goal, a special numerical filter is constructed by extracting and improving a modulation function from the G-channel sampling-gained hologram in Fourier frequency domain based on a color CCD detector. The quantitative analysis on the zero-order term suppression and image distortion control in both amplitude and phase for the filter optimization are presented in detail. The experimental result agrees with theoretical prediction well and proves the effectiveness of this method.