Improved digital holographic reconstruction algorithm by zero-order term elimination based on Riesz-transform

In order to address the issue of low effective bandwidth ratio in off-axis digital holography, which is caused by the impact of zeroth- and first-order terms on the first-order term, an improved digital holographic reconstruction algorithm by zeroth-order term elimination based on the Riesz transform is proposed in this paper. First, an off-axis hologram is convolved with the Riesz kernels. Then, in the spectrum, the zeroth-order term is effectively eliminated by a singularity at the origin of the Riesz kernels, which can improve the effective bandwidth ratio and make the best use of the bandwidth. Consequently, the phase with better reconstruction quality can be retrieved. Compared to traditional reconstruction algorithms, this algorithm can effectively eliminate the zeroth-order term, which allows high-resolution amplitude and phase retrieval. Finally, simulated and experimental results are presented to validate the effectiveness of the proposed algorithm.