Phase-shift reconstruction imaging analysis in off-axis digital holographic microscopy with structured illumination

Abstract

Reconstructing super-resolution images typically requires three or four phase-shift holograms for spectrum decomposing and combination. In the process of recording holograms, the phase shift accuracy of the instrument and environmental vibration will affect the spectrum decomposing results, resulting in reconstruction artifacts. In the simulation, with respect to two kinds of phase shift biases, the digital holographic reconstruction results with three-step and four-step phase-shift methods are compared. All the phase shift methods are much dependent on the accuracy of phase shift values. The four-step phase shift method needs to record more holograms, so its ability to cope with bias is poor, and its spectrum decomposing results is inferior to that with the three-step phase shift method. In a structured-illumination off-axis digital holographic system, the super-resolution imaging for amplitude and phase reconstructions is performed in experiment by using three-step phase shift processing. The results demonstrate that the resolution of the reconstructed images is improved.