Lensless super-resolved quantitative phase imaging with cm-level lateral translations of two glass plates.

In this Letter, we propose a new, to the best of our knowledge, lensless on-chip holographic microscopy platform, which can acquire sub-pixel-shifting holograms through centimeter (cm)-level lateral translations. An LED light source is used to illuminate the sample, and two orthogonally tilted step-structure glass plates are inserted into the optical path. By merely displacing the glass plates under cm-level precision, a series of holograms with sub-pixel displacements can be obtained. Combined with our improved pixel super-resolution (PSR) algorithm, high-quality PSR phase imaging can be achieved. Tests on the high-resolution USAF1951 target demonstrate that the system can achieve a half-width resolution of 870 nm by a camera with a pixel size of 1.67 µm. Additionally, imaging experiments were conducted on phase-type sinusoidal gratings, yeasts, red blood cells, and lilium ovary sections, respectively. The results show that the system can achieve large field-of-view, high-resolution phase imaging under low-cost hardware conditions and holds promise for its applications in biology and medicine.