An enhanced multimode phase imaging method based on the transport of intensity equation

Area of Science:

• Biomedical Optics
• Computational Imaging
• Microscopy

Background:

• Label-free biological cell imaging requires high-contrast phase imaging in natural settings.
• Differential interference contrast (DIC) and Zernike phase contrast (ZPC) improve contrast by encoding phase into intensity.
• Existing methods have limitations in achieving multimode contrast enhancement for unstained specimens.

Purpose of the Study:

• To propose an improved multimode phase imaging method for unstained biological samples.
• To enhance image contrast using a combination of conventional microscopy and computational imaging.
• To validate the accuracy and viability of the proposed technique through simulations and experiments.

Main Methods:

• Utilized the transport of intensity equation (TIE) to solve for quantitative phase information.
• Integrated an adaptive aperture adjustment ZPC imaging module.
• Employed a rotationally symmetric shear-based technique for isotropic DIC.

Main Results:

• The proposed method enables multimode contrast-enhanced observation of unstained specimens.
• Numerical simulations and optical experiments validated the technique's accuracy and viability.
• The Michelson contrast in ZPC imaging of a resolution plate increased from 0.196 to 0.394.

Conclusions:

• The developed TIE-based multimode phase imaging method significantly enhances contrast for label-free biological samples.
• This technique offers a viable approach for advanced microscopy and unstained specimen observation.
• The integration of computational imaging with adaptive ZPC and isotropic DIC provides superior phase contrast capabilities.