In-focus quantitative phase imaging from defocused off-axis holograms: synergistic reconstruction framework.

Area of Science:

• * Biomedical optics
• * Microscopy
• * Computational imaging

Background:

• * Digital holographic microscopy (DHM) reconstructs 3D quantitative phase distributions from defocused holograms.
• * Conventional methods sequentially reconstruct complex amplitude and then focus, often leading to phase distortions.
• * Off-axis DHM systems can introduce linear tilt, complicating image reconstruction.

Purpose of the Study:

• * To develop a synergistic computational framework for off-axis DHM.
• * To simultaneously compensate for linear tilt and autofocus defocused holograms.
• * To achieve in-focus phase images with minimal distortion.

Main Methods:

• * Developed a novel computational framework integrating tilt compensation and autofocusing.
• * Employed a cost function minimization approach for simultaneous parameter correction.
• * Validated the method using defocused holograms of biological specimens.

Main Results:

• * Successfully reconstructed in-focus quantitative phase images without phase distortions.
• * Demonstrated accurate 3D reconstruction of human red blood cells.
• * Provided high-resolution 3D images of dynamic sperm cells.

Conclusions:

• * The proposed computational framework offers an efficient and accurate solution for DHM image reconstruction.
• * This method enhances the capability of DHM for analyzing dynamic biological samples.
• * The tool effectively addresses challenges of tilt and defocus in off-axis holographic microscopy.