Diagonal illumination scheme for Fourier ptychographic microscopy: resolution doubling and aliasing minimization

Area of Science:

• Optical Imaging
• Computational Microscopy
• Biophotonics

Background:

• Fourier ptychographic microscopy (FPM) offers high-throughput, wide-field, high-resolution imaging.
• Quantitative phase imaging (QPI) with FPM is valuable for large-scale cell analysis.
• Detector undersampling in FPM causes spectrum aliasing, degrading QPI performance, especially with high numerical aperture objectives.

Purpose of the Study:

• To introduce a diagonal illumination scheme for FPM to mitigate spectrum aliasing.
• To enable high-resolution QPI under limited detector sampling rates.
• To improve the resolution, efficiency, and quality of FPM-based QPI.

Main Methods:

• Developed and implemented a diagonal LED illumination strategy for FPM.
• Integrated the diagonal illumination with a color camera for single-shot acquisition.
• Utilized theoretical analysis, simulations, and experimental validation with resolution targets and live cells.

Main Results:

• The diagonal illumination scheme effectively minimizes spectrum aliasing in FPM.
• Achieved incoherent diffraction-limited resolution for QPI with limited detector sampling.
• Demonstrated high-throughput, single-shot QPI capabilities.

Conclusions:

• The proposed diagonal illumination scheme is a viable solution for overcoming spectrum aliasing in FPM.
• This method enables high-resolution QPI even with undersampled detectors.
• Provides a guideline for designing future FPM platforms for high-speed and high-quality QPI.