Single-shot off-axis hologram reconstruction by using fractional Fourier transform domain filtering based on spatial-domain extending and hologram partitioning

A method of single-shot off-axis digital hologram reconstruction by extending and partitioning the hologram in its spatial domain, filtering in its fractional Fourier transform domain, and merging in the reconstruction imaging domain is presented, which can enhance the resolution of the reconstructed amplitude and phase maps. In the experiment, the reconstruction results of the amplitude-type and phase-type objects demonstrate the capability for improving the reconstruction resolution in effect. The procedure of partitioning the expanded hologram of spatial domain zero-padding into two slightly redundant halves is described in detail. The noise evaluation parameter for partition line noise is defined, and the effect of redundant partitioning on reducing partition line noise is verified quantitatively.