Sampling moiré method: a tool for sensing quadratic phase distortion and its correction for accurate quantitative...

Area of Science:

• Optical microscopy
• Biomedical imaging
• Phase contrast imaging

Background:

• Quantitative phase microscopy (QPM) offers label-free, high-sensitivity imaging for live cells.
• Accurate QPM phase recovery depends on interferogram fringe shape and density.
• Wavefront curvature mismatch causes quadratic phase aberrations in QPM.

Purpose of the Study:

• To implement and validate a sampling moiré method for real-time sensing and correction of wavefront curvature mismatch in QPM.
• To improve phase recovery accuracy in QPM by addressing quadratic phase aberrations.

Main Methods:

• Implemented a sampling moiré method by zooming out interferograms to generate moiré fringes for curvature identification.
• Tested the method's accuracy using white light (temporal coherence ~1.6 µm).
• Compared phase recovery accuracy against the principle component analysis method.

Main Results:

• Successfully removed quadratic phase aberration from USAF resolution targets and biological tissue samples.
• Demonstrated accurate wavefront curvature mismatch correction.
• Achieved phase recovery accuracy superior to the standard principle component analysis method.

Conclusions:

• The sampling moiré method effectively corrects wavefront curvature mismatch in QPM in real-time.
• The proposed technique requires no additional optical components or post-processing.
• This method facilitates high-throughput and accurate quantitative phase imaging.