LED based large field of view off-axis quantitative phase contrast microscopy by hologram multiplexing

Area of Science:

• Optics and Photonics
• Biomedical Imaging
• Microscopy

Background:

• Quantitative phase imaging (QPI) is crucial for label-free biological sample analysis.
• Traditional interferometry faces challenges with low temporal coherence sources, leading to noise and reduced field of view.
• Digital holographic microscopy (DHM) offers advanced imaging capabilities but requires further optimization for biological applications.

Purpose of the Study:

• To develop a single-shot, self-referencing digital holographic microscope for large field-of-view quantitative phase imaging.
• To address limitations of low temporally coherent sources in interferometric setups.
• To enhance signal-to-noise ratio and field of view in holographic microscopy.

Main Methods:

• A wavefront division multiplexing digital holographic microscope was designed and implemented.
• Multiple Fresnel Biprisms were employed for hologram multiplexing, accommodating low temporal coherence sources.
• LED illumination sources (visible and UV) were utilized to reduce speckle noise and cost.
• The system was tested using polystyrene microspheres and human erythrocytes.

Main Results:

• The developed microscope achieved large field-of-view quantitative phase imaging.
• The use of Fresnel Biprisms effectively managed low temporal coherence, enhancing the field of view and signal-to-noise ratio.
• Speckle noise was reduced, and the cost and form factor of the setup were improved.
• Successful imaging of polystyrene microspheres and human erythrocytes was demonstrated.

Conclusions:

• The novel digital holographic microscope effectively overcomes challenges associated with low temporal coherence sources.
• The system provides a cost-effective, high-performance solution for large field-of-view quantitative phase imaging of biological samples.
• This technique holds promise for advanced label-free imaging in various biological research areas.