Physical pupil manipulation for speckle reduction in digital holographic microscopy

• Main Authors: Carlos Buitrago-Duque, Jorge Garcia-Sucerquia
• Format: Article
• Language: English
• Published: Elsevier 2021-01-01
• Series: Heliyon
• Subjects: Speckle; Digital holography; Image enhancement; Quantitative phase imaging
• Online Access: http://www.sciencedirect.com/science/article/pii/S2405844021002036

The reduction of speckle noise by physically changing the pupil of the imaging system, as first envisioned in optical holography, is experimentally applied to a digital holographic microscope (DHM). The imaging pupil of a DHM, operating in image plane telecentric-afocal architecture, is changed in a controlled way between successive recordings, allowing the shooting of multiple partially-decorrelated holograms. Averaging the numerically reconstructed holograms yields amplitude and/or phase images with reduced speckle noise. Experimental results of biological specimens and a phase-only resolution test show the feasibility to recover micron-sized features in images with reduced speckle noise.