Phase aberration separation for holographic microscopy by alternating direction sparse optimization.

Area of Science:

• Biomedical optics
• Quantitative phase imaging
• Microscopy

Background:

• Label-free tissue imaging relies on quantitative phase imaging (QPI).
• QPI is sensitive to optical field changes but susceptible to phase aberrations.
• Phase aberrations degrade the quality of reconstructed phase images.

Purpose of the Study:

• To develop a robust method for extracting phase aberrations in QPI.
• To improve the fidelity of phase reconstruction for label-free tissue imaging.
• To reduce the stringent alignment requirements for holographic microscopes.

Main Methods:

• Utilized a variable sparse splitting framework for quantitative phase aberration extraction.
• Employed an alternating direction aberration-free method.
• Decomposed optimization and regularization into object and aberration terms.
• Formulated aberration extraction as a convex quadratic problem for direct decomposition using basis functions (e.g., Zernike polynomials).

Main Results:

• Successfully extracted and eliminated global background phase aberrations.
• Achieved faithful phase reconstruction by removing aberrations.
• Demonstrated aberration-free 2D and 3D imaging experiments.
• Showcased relaxed alignment requirements for holographic microscopes.

Conclusions:

• The proposed method effectively removes phase aberrations in QPI.
• This technique enhances the quality of label-free tissue morphology and dynamics imaging.
• The findings simplify holographic microscopy operation by easing alignment constraints.