Spatial Consistency Calibration Based on Phase Difference Minimization for Parallel Slightly Off-Axis Digital Holographic Microscopy

In this study, we propose a spatial consistency calibration method for slightly off-axis digital holographic microscopy (SO-DHM). The acquisition of relative position errors is summarized into a solution of a nonlinear optimization problem in which the root mean squared error of phase aberration of holograms is minimized. The particle swarm optimization algorithm is chosen to solve this optimization problem due to its simple structure, high convergence efficiency, and robust global search ability. Phase-only wavefronts based on phase aberration, which remove the influence of noise, are used for calibration. The simulation result indicates that the proposed method has subpixel-level precision, and the experiment demonstrates the effectiveness of the proposed method in the SO-DHM system.