Coded aperture structured illumination digital holographic microscopy for superresolution imaging.

Area of Science:

• Optics and Photonics
• Microscopy Techniques
• Image Reconstruction

Background:

• Digital holographic microscopy (DHM) enables 3D imaging but is limited by spatial frequency coverage.
• Structured illumination (SI) enhances resolution but typically requires multiple exposures and temporal phase-shifting.
• Compressive sensing (CS) offers a way to reconstruct signals from undersampled data.

Purpose of the Study:

• To develop a novel coded aperture structured illumination (CASI) technique for DHM.
• To achieve superresolution imaging in DHM with a single-shot acquisition.
• To eliminate the need for temporal phase-shifting in SI-based DHM.

Main Methods:

• Generation of a CASI wave using two binary phase codes (0° and 120°) for spatial phase shifting.
• Interference of the CASI wave with a reference wave to form a coded Fresnel hologram in a single exposure.
• Application of compressive sensing (CS) algorithms to reconstruct phase-shifted illumination patterns and retrieve missing data.

Main Results:

• Successful implementation of CASI in DHM for superresolution imaging.
• Demonstration of single-shot acquisition, avoiding temporal phase-shifting.
• Separation of overlapped spatial frequencies leading to enhanced spatial frequency coverage.

Conclusions:

• The proposed CASI technique effectively enhances resolution in DHM.
• Single-shot acquisition with CS significantly simplifies the SI process in DHM.
• This method provides a pathway to advanced superresolution microscopy using DHM.