Color-multiplexed 3D differential phase contrast microscopy with optimal annular illumination

Area of Science:

• Biomedical Optics
• Quantitative Phase Imaging
• Microscopy

Background:

• Quantitative phase imaging (QPI) quantifies refractive index variations in live cells and tissues.
• Conventional 3D differential phase contrast (3D DPC) microscopy suffers from noise and artifacts due to illumination limitations.

Purpose of the Study:

• To develop an optimized 3D DPC microscopy method for improved imaging quality.
• To enhance refractive index tomography of biological samples.

Main Methods:

• Derived optimal conditions for the 3D phase transfer function (PTF).
• Implemented 3D DPC microscopy with optimal annular illumination.
• Utilized 1/2 annular multiplexed illumination to increase imaging speed.

Main Results:

• The proposed method minimizes missing frequency components, improving noise-robustness.
• Achieved significantly increased phase contrast and reduced low-frequency artifacts.
• Demonstrated accurate 3D refractive index tomography of various samples, including cells and tissues.

Conclusions:

• A novel, compact 3D DPC microscope was developed using programmable LED illumination.
• The optimized annular illumination significantly enhances imaging performance.
• This technique holds potential for significant applications in biomedical research.