Imaging quality and resolution enhancement by iterative phase retrieval in THz off-axis digital holography

The intrinsic resolution of 2.52 THz off-axis digital holography system is known to be diffraction limited. However, in practical recording condition, reference wavefront would inevitably suffer excessive diffraction or obstruction with large off-axis angle. Consequently, the theoretical resolution cannot be achieved, and the imaging quality is degraded. We propose a phase-retrieval-assisted solution to correct the errors caused by inaccurate reference wave. Experimental results demonstrate enhanced imaging quality and recovered lateral resolution.